diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 1ddfe2fceb..6214e6ed57 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -60,7 +60,7 @@
 void hmp_handle_error(Monitor *mon, Error *err)
 {
     if (err) {
-        error_reportf_err(err, "Error: ");
+        error_report_err(err);
     }
 }
 
diff --git a/tests/qemu-iotests/020.out b/tests/qemu-iotests/020.out
index 4b722b2dd0..41171a3795 100644
--- a/tests/qemu-iotests/020.out
+++ b/tests/qemu-iotests/020.out
@@ -1093,5 +1093,5 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 backing_file=json:{'driv
                              }}}
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Block job failed: No space left on device
+qemu-img: error: Block job failed: No space left on device
 *** done
diff --git a/tests/qemu-iotests/026.out b/tests/qemu-iotests/026.out
index ff0817b6f2..554eb0005b 100644
--- a/tests/qemu-iotests/026.out
+++ b/tests/qemu-iotests/026.out
@@ -3,7 +3,7 @@ Errors while writing 128 kB
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l1_update; errno: 5; imm: off; once: on; write
+Event: l1_update; errno: 5; imm: off; once: on; write 
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -13,21 +13,21 @@ write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l1_update; errno: 5; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+Event: l1_update; errno: 5; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_update; errno: 5; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l1_update; errno: 28; imm: off; once: on; write
+Event: l1_update; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -37,21 +37,21 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l1_update; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: l1_update; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_update; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_load; errno: 5; imm: off; once: on; write
+Event: l2_load; errno: 5; imm: off; once: on; write 
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 write failed: Input/output error
@@ -67,7 +67,7 @@ read failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_load; errno: 5; imm: off; once: off; write
+Event: l2_load; errno: 5; imm: off; once: off; write 
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 write failed: Input/output error
@@ -83,7 +83,7 @@ read failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_load; errno: 28; imm: off; once: on; write
+Event: l2_load; errno: 28; imm: off; once: on; write 
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 write failed: No space left on device
@@ -99,7 +99,7 @@ read failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_load; errno: 28; imm: off; once: off; write
+Event: l2_load; errno: 28; imm: off; once: off; write 
 wrote 131072/131072 bytes at offset 0
 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 write failed: No space left on device
@@ -115,7 +115,7 @@ read failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_update; errno: 5; imm: off; once: on; write
+Event: l2_update; errno: 5; imm: off; once: on; write 
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -125,21 +125,21 @@ write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_update; errno: 5; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+Event: l2_update; errno: 5; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 5; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_update; errno: 28; imm: off; once: on; write
+Event: l2_update; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -149,21 +149,21 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_update; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: l2_update; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_update; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_alloc_write; errno: 5; imm: off; once: on; write
+Event: l2_alloc_write; errno: 5; imm: off; once: on; write 
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -173,21 +173,21 @@ write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_alloc_write; errno: 5; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+Event: l2_alloc_write; errno: 5; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_alloc_write; errno: 5; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_alloc_write; errno: 28; imm: off; once: on; write
+Event: l2_alloc_write; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -197,21 +197,21 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: l2_alloc_write; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: l2_alloc_write; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l2_alloc_write; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: write_aio; errno: 5; imm: off; once: on; write
+Event: write_aio; errno: 5; imm: off; once: on; write 
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -221,21 +221,21 @@ write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: write_aio; errno: 5; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+Event: write_aio; errno: 5; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: write_aio; errno: 5; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: write_aio; errno: 28; imm: off; once: on; write
+Event: write_aio; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -245,21 +245,21 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: write_aio; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: write_aio; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: write_aio; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_load; errno: 5; imm: off; once: on; write
+Event: refblock_load; errno: 5; imm: off; once: on; write 
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -269,21 +269,21 @@ write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_load; errno: 5; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+Event: refblock_load; errno: 5; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_load; errno: 5; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_load; errno: 28; imm: off; once: on; write
+Event: refblock_load; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -293,21 +293,21 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_load; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: refblock_load; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_load; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_update_part; errno: 5; imm: off; once: on; write
+Event: refblock_update_part; errno: 5; imm: off; once: on; write 
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -317,21 +317,21 @@ write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_update_part; errno: 5; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+Event: refblock_update_part; errno: 5; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 5; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_update_part; errno: 28; imm: off; once: on; write
+Event: refblock_update_part; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -341,21 +341,21 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_update_part; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: refblock_update_part; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_update_part; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc; errno: 5; imm: off; once: on; write
+Event: refblock_alloc; errno: 5; imm: off; once: on; write 
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -365,21 +365,21 @@ write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc; errno: 5; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+Event: refblock_alloc; errno: 5; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc; errno: 5; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc; errno: 28; imm: off; once: on; write
+Event: refblock_alloc; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -389,21 +389,21 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: refblock_alloc; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: cluster_alloc; errno: 5; imm: off; once: on; write
+Event: cluster_alloc; errno: 5; imm: off; once: on; write 
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -413,7 +413,7 @@ write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: cluster_alloc; errno: 5; imm: off; once: off; write
+Event: cluster_alloc; errno: 5; imm: off; once: off; write 
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -423,7 +423,7 @@ write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: cluster_alloc; errno: 28; imm: off; once: on; write
+Event: cluster_alloc; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -433,7 +433,7 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: cluster_alloc; errno: 28; imm: off; once: off; write
+Event: cluster_alloc; errno: 28; imm: off; once: off; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -446,7 +446,7 @@ No errors were found on the image.
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc_hookup; errno: 28; imm: off; once: on; write
+Event: refblock_alloc_hookup; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -456,21 +456,21 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc_hookup; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: refblock_alloc_hookup; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_hookup; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc_write; errno: 28; imm: off; once: on; write
+Event: refblock_alloc_write; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -480,21 +480,21 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc_write; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: refblock_alloc_write; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: on; write
+Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -504,21 +504,21 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc_write_table; errno: 28; imm: off; once: on; write
+Event: refblock_alloc_write_table; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -528,21 +528,21 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc_write_table; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: refblock_alloc_write_table; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_write_table; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc_switch_table; errno: 28; imm: off; once: on; write
+Event: refblock_alloc_switch_table; errno: 28; imm: off; once: on; write 
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -552,16 +552,16 @@ write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
-Event: refblock_alloc_switch_table; errno: 28; imm: off; once: off; write
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+Event: refblock_alloc_switch_table; errno: 28; imm: off; once: off; write 
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: refblock_alloc_switch_table; errno: 28; imm: off; once: off; write -b
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 
@@ -595,8 +595,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_write_table; errno: 5; imm: off; once: off
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -607,8 +607,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_write_table; errno: 28; imm: off; once: off
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -619,8 +619,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_activate_table; errno: 5; imm: off; once: off
-qemu-io: Failed to flush the L2 table cache: Input/output error
-qemu-io: Failed to flush the refcount block cache: Input/output error
+qemu-io: error: Failed to flush the L2 table cache: Input/output error
+qemu-io: error: Failed to flush the refcount block cache: Input/output error
 write failed: Input/output error
 No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
@@ -631,8 +631,8 @@ No errors were found on the image.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 
 Event: l1_grow_activate_table; errno: 28; imm: off; once: off
-qemu-io: Failed to flush the L2 table cache: No space left on device
-qemu-io: Failed to flush the refcount block cache: No space left on device
+qemu-io: error: Failed to flush the L2 table cache: No space left on device
+qemu-io: error: Failed to flush the refcount block cache: No space left on device
 write failed: No space left on device
 No errors were found on the image.
 
diff --git a/tests/qemu-iotests/036.out b/tests/qemu-iotests/036.out
index 0b52b934e1..b08e7c1cc6 100644
--- a/tests/qemu-iotests/036.out
+++ b/tests/qemu-iotests/036.out
@@ -6,18 +6,18 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 incompatible_features     [63]
 compatible_features       []
 autoclear_features        []
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): Unknown incompatible feature: 8000000000000000
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): Test feature
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): Unknown incompatible feature: 8000000000000000
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): Test feature
 
 === Image with multiple incompatible feature bits ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): Unknown incompatible feature: e000000000000000
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): Test feature, Unknown incompatible feature: 6000000000000000
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): Test feature, Unknown incompatible feature: c000000000000000
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): test1, test2, Unknown incompatible feature: 8000000000000000
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): test1, test2, test3
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): test2, Unknown incompatible feature: a000000000000000
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): Unknown incompatible feature: e000000000000000
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): Test feature, Unknown incompatible feature: 6000000000000000
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): Test feature, Unknown incompatible feature: c000000000000000
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): test1, test2, Unknown incompatible feature: 8000000000000000
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): test1, test2, test3
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Unsupported IMGFMT feature(s): test2, Unknown incompatible feature: a000000000000000
 === Create image with unknown autoclear feature bit ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
diff --git a/tests/qemu-iotests/043.out b/tests/qemu-iotests/043.out
index 0280f999ce..a6f307ceeb 100644
--- a/tests/qemu-iotests/043.out
+++ b/tests/qemu-iotests/043.out
@@ -2,19 +2,19 @@ QA output created by 043
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 
 == backing file references self ==
-qemu-img: Backing file 'TEST_DIR/t.IMGFMT' creates an infinite loop.
+qemu-img: error: Backing file 'TEST_DIR/t.IMGFMT' creates an infinite loop.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 backing_file=TEST_DIR/t.IMGFMT.base
 
 == parent references self ==
-qemu-img: Backing file 'TEST_DIR/t.IMGFMT' creates an infinite loop.
+qemu-img: error: Backing file 'TEST_DIR/t.IMGFMT' creates an infinite loop.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 backing_file=TEST_DIR/t.IMGFMT.1.base
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 backing_file=TEST_DIR/t.IMGFMT.2.base
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 backing_file=TEST_DIR/t.IMGFMT.3.base
 
 == ancestor references another ancestor ==
-qemu-img: Backing file 'TEST_DIR/t.IMGFMT.2.base' creates an infinite loop.
+qemu-img: error: Backing file 'TEST_DIR/t.IMGFMT.2.base' creates an infinite loop.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 backing_file=TEST_DIR/t.IMGFMT.1.base
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 backing_file=TEST_DIR/t.IMGFMT.2.base
diff --git a/tests/qemu-iotests/049.out b/tests/qemu-iotests/049.out
index affa55b341..60d75f0290 100644
--- a/tests/qemu-iotests/049.out
+++ b/tests/qemu-iotests/049.out
@@ -92,39 +92,39 @@ Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=1649267441664 cluster_size=65536 l
 == 3. Invalid sizes ==
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 -- -1024
-qemu-img: Image size must be less than 8 EiB!
+qemu-img: error: Image size must be less than 8 EiB!
 
 qemu-img create -f qcow2 -o size=-1024 TEST_DIR/t.qcow2
-qemu-img: TEST_DIR/t.qcow2: Value '-1024' is out of range for parameter 'size'
+qemu-img: error: TEST_DIR/t.qcow2: Value '-1024' is out of range for parameter 'size'
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 -- -1k
-qemu-img: Image size must be less than 8 EiB!
+qemu-img: error: Image size must be less than 8 EiB!
 
 qemu-img create -f qcow2 -o size=-1k TEST_DIR/t.qcow2
-qemu-img: TEST_DIR/t.qcow2: Value '-1k' is out of range for parameter 'size'
+qemu-img: error: TEST_DIR/t.qcow2: Value '-1k' is out of range for parameter 'size'
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 -- 1kilobyte
-qemu-img: Invalid image size specified! You may use k, M, G, T, P or E suffixes for
-qemu-img: kilobytes, megabytes, gigabytes, terabytes, petabytes and exabytes.
+qemu-img: error: Invalid image size specified! You may use k, M, G, T, P or E suffixes for 
+qemu-img: error: kilobytes, megabytes, gigabytes, terabytes, petabytes and exabytes.
 
 qemu-img create -f qcow2 -o size=1kilobyte TEST_DIR/t.qcow2
-qemu-img: TEST_DIR/t.qcow2: Parameter 'size' expects a non-negative number below 2^64
+qemu-img: error: TEST_DIR/t.qcow2: Parameter 'size' expects a non-negative number below 2^64
 Optional suffix k, M, G, T, P or E means kilo-, mega-, giga-, tera-, peta-
 and exabytes, respectively.
 
 qemu-img create -f qcow2 TEST_DIR/t.qcow2 -- foobar
-qemu-img: Invalid image size specified! You may use k, M, G, T, P or E suffixes for
-qemu-img: kilobytes, megabytes, gigabytes, terabytes, petabytes and exabytes.
+qemu-img: error: Invalid image size specified! You may use k, M, G, T, P or E suffixes for 
+qemu-img: error: kilobytes, megabytes, gigabytes, terabytes, petabytes and exabytes.
 
 qemu-img create -f qcow2 -o size=foobar TEST_DIR/t.qcow2
-qemu-img: TEST_DIR/t.qcow2: Parameter 'size' expects a non-negative number below 2^64
+qemu-img: error: TEST_DIR/t.qcow2: Parameter 'size' expects a non-negative number below 2^64
 Optional suffix k, M, G, T, P or E means kilo-, mega-, giga-, tera-, peta-
 and exabytes, respectively.
 
 == 4. Specify size twice (-o and traditional parameter) ==
 
 qemu-img create -f qcow2 -o size=10M TEST_DIR/t.qcow2 20M
-qemu-img: TEST_DIR/t.qcow2: The image size must be specified only once
+qemu-img: error: TEST_DIR/t.qcow2: The image size must be specified only once
 
 == Check correct interpretation of suffixes for cluster size ==
 
@@ -167,11 +167,11 @@ qemu-img create -f qcow2 -o compat=1.1 TEST_DIR/t.qcow2 64M
 Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=1.1 cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o compat=0.42 TEST_DIR/t.qcow2 64M
-qemu-img: TEST_DIR/t.qcow2: Invalid parameter '0.42'
+qemu-img: error: TEST_DIR/t.qcow2: Invalid parameter '0.42'
 Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=0.42 cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o compat=foobar TEST_DIR/t.qcow2 64M
-qemu-img: TEST_DIR/t.qcow2: Invalid parameter 'foobar'
+qemu-img: error: TEST_DIR/t.qcow2: Invalid parameter 'foobar'
 Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=foobar cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 == Check preallocation option ==
@@ -183,7 +183,7 @@ qemu-img create -f qcow2 -o preallocation=metadata TEST_DIR/t.qcow2 64M
 Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=65536 preallocation=metadata lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o preallocation=1234 TEST_DIR/t.qcow2 64M
-qemu-img: TEST_DIR/t.qcow2: Invalid parameter '1234'
+qemu-img: error: TEST_DIR/t.qcow2: Invalid parameter '1234'
 Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 cluster_size=65536 preallocation=1234 lazy_refcounts=off refcount_bits=16
 
 == Check encryption option ==
@@ -206,7 +206,7 @@ qemu-img create -f qcow2 -o compat=0.10,lazy_refcounts=off TEST_DIR/t.qcow2 64M
 Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=0.10 cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 qemu-img create -f qcow2 -o compat=0.10,lazy_refcounts=on TEST_DIR/t.qcow2 64M
-qemu-img: TEST_DIR/t.qcow2: Lazy refcounts only supported with compatibility level 1.1 and above (use version=v3 or greater)
+qemu-img: error: TEST_DIR/t.qcow2: Lazy refcounts only supported with compatibility level 1.1 and above (use version=v3 or greater)
 Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=67108864 compat=0.10 cluster_size=65536 lazy_refcounts=on refcount_bits=16
 
 *** done
diff --git a/tests/qemu-iotests/051.pc.out b/tests/qemu-iotests/051.pc.out
index 0ea80d35f0..ddb035cf10 100644
--- a/tests/qemu-iotests/051.pc.out
+++ b/tests/qemu-iotests/051.pc.out
@@ -5,46 +5,46 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728 backing_file=TEST_DIR/
 === Unknown option ===
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=,if=none,id=drive0
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=,if=none,id=drive0: Block format 'qcow2' does not support the option 'unknown_opt'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=,if=none,id=drive0: error: Block format 'qcow2' does not support the option 'unknown_opt'
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=on,if=none,id=drive0
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=on,if=none,id=drive0: Block format 'qcow2' does not support the option 'unknown_opt'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=on,if=none,id=drive0: error: Block format 'qcow2' does not support the option 'unknown_opt'
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=1234,if=none,id=drive0
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=1234,if=none,id=drive0: Block format 'qcow2' does not support the option 'unknown_opt'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=1234,if=none,id=drive0: error: Block format 'qcow2' does not support the option 'unknown_opt'
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=foo,if=none,id=drive0
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=foo,if=none,id=drive0: Block format 'qcow2' does not support the option 'unknown_opt'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,unknown_opt=foo,if=none,id=drive0: error: Block format 'qcow2' does not support the option 'unknown_opt'
 
 
 === Unknown protocol option ===
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=: Block protocol 'file' doesn't support the option 'unknown_opt'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=: error: Block protocol 'file' doesn't support the option 'unknown_opt'
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=on
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=on: Block protocol 'file' doesn't support the option 'unknown_opt'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=on: error: Block protocol 'file' doesn't support the option 'unknown_opt'
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=1234
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=1234: Block protocol 'file' doesn't support the option 'unknown_opt'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=1234: error: Block protocol 'file' doesn't support the option 'unknown_opt'
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=foo
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=foo: Block protocol 'file' doesn't support the option 'unknown_opt'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,file.unknown_opt=foo: error: Block protocol 'file' doesn't support the option 'unknown_opt'
 
 
 === Invalid format ===
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=foo
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=foo: Unknown driver 'foo'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=foo: error: Unknown driver 'foo'
 
 Testing: -drive file=TEST_DIR/t.qcow2,driver=foo
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,driver=foo: Unknown driver 'foo'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,driver=foo: error: Unknown driver 'foo'
 
 Testing: -drive file=TEST_DIR/t.qcow2,driver=raw,format=qcow2
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,driver=raw,format=qcow2: Cannot specify both 'driver' and 'format'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,driver=raw,format=qcow2: error: Cannot specify both 'driver' and 'format'
 
 Testing: -drive file=TEST_DIR/t.qcow2,driver=qcow2,format=qcow2
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,driver=qcow2,format=qcow2: Cannot specify both 'driver' and 'format'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,driver=qcow2,format=qcow2: error: Cannot specify both 'driver' and 'format'
 
 
 === Node names ===
@@ -54,27 +54,27 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) quit
 
 Testing: -drive file=TEST_DIR/t.qcow2,node-name=x1234567890123456789012345678901
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=x1234567890123456789012345678901: Node name too long
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=x1234567890123456789012345678901: error: Node name too long
 
 Testing: -drive file=TEST_DIR/t.qcow2,node-name=All-Types.of_all0wed_chars
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) quit
 
 Testing: -drive file=TEST_DIR/t.qcow2,node-name=123foo
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=123foo: Invalid node name
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=123foo: error: Invalid node name
 
 Testing: -drive file=TEST_DIR/t.qcow2,node-name=_foo
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=_foo: Invalid node name
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=_foo: error: Invalid node name
 
 Testing: -drive file=TEST_DIR/t.qcow2,node-name=foo#12
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=foo#12: Invalid node name
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,node-name=foo#12: error: Invalid node name
 
 
 === Device without drive ===
 
 Testing: -device VIRTIO_SCSI -device scsi-hd
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: -device scsi-hd: drive property not set
+(qemu) QEMU_PROG: -device scsi-hd: error: drive property not set
 
 
 === Overriding backing file ===
@@ -89,13 +89,13 @@ drive0 (NODE_NAME): json:{"backing": {"driver": "qcow2", "file": {"driver": "fil
 (qemu) quit
 
 Testing: -drive file=TEST_DIR/t.qcow2,driver=raw,backing.file.filename=TEST_DIR/t.qcow2.orig
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,driver=raw,backing.file.filename=TEST_DIR/t.qcow2.orig: Driver doesn't support backing files
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,driver=raw,backing.file.filename=TEST_DIR/t.qcow2.orig: error: Driver doesn't support backing files
 
 Testing: -drive file=TEST_DIR/t.qcow2,file.backing.driver=file,file.backing.filename=TEST_DIR/t.qcow2.orig
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.backing.driver=file,file.backing.filename=TEST_DIR/t.qcow2.orig: Driver doesn't support backing files
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.backing.driver=file,file.backing.filename=TEST_DIR/t.qcow2.orig: error: Driver doesn't support backing files
 
 Testing: -drive file=TEST_DIR/t.qcow2,file.backing.driver=qcow2,file.backing.file.filename=TEST_DIR/t.qcow2.orig
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.backing.driver=qcow2,file.backing.file.filename=TEST_DIR/t.qcow2.orig: Driver doesn't support backing files
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,file.backing.driver=qcow2,file.backing.file.filename=TEST_DIR/t.qcow2.orig: error: Driver doesn't support backing files
 
 
 === Enable and disable lazy refcounting on the command line, plus some invalid values ===
@@ -110,20 +110,20 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) quit
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=: Parameter 'lazy-refcounts' expects 'on' or 'off'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=: error: Parameter 'lazy-refcounts' expects 'on' or 'off'
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=42
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=42: Parameter 'lazy-refcounts' expects 'on' or 'off'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=42: error: Parameter 'lazy-refcounts' expects 'on' or 'off'
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=foo
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=foo: Parameter 'lazy-refcounts' expects 'on' or 'off'
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=foo: error: Parameter 'lazy-refcounts' expects 'on' or 'off'
 
 
 === With version 2 images enabling lazy refcounts must fail ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=on
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=on: Lazy refcounts require a qcow2 image with at least qemu 1.1 compatibility level
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=on: error: Lazy refcounts require a qcow2 image with at least qemu 1.1 compatibility level
 
 Testing: -drive file=TEST_DIR/t.qcow2,format=qcow2,lazy-refcounts=off
 QEMU X.Y.Z monitor - type 'help' for more information
@@ -142,11 +142,11 @@ QEMU X.Y.Z monitor - type 'help' for more information
 
 Testing: -drive if=ide
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: Initialization of device ide-hd failed: Device needs media, but drive is empty
+(qemu) QEMU_PROG: error: Initialization of device ide-hd failed: Device needs media, but drive is empty
 
 Testing: -drive if=virtio
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: -drive if=virtio: Device needs media, but drive is empty
+(qemu) QEMU_PROG: -drive if=virtio: error: Device needs media, but drive is empty
 
 Testing: -drive if=none,id=disk -device ide-cd,drive=disk
 QEMU X.Y.Z monitor - type 'help' for more information
@@ -159,43 +159,43 @@ QEMU X.Y.Z monitor - type 'help' for more information
 Testing: -drive if=none,id=disk -device ide-drive,drive=disk
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) QEMU_PROG: -device ide-drive,drive=disk: warning: 'ide-drive' is deprecated, please use 'ide-hd' or 'ide-cd' instead
-QEMU_PROG: -device ide-drive,drive=disk: Device needs media, but drive is empty
+QEMU_PROG: -device ide-drive,drive=disk: error: Device needs media, but drive is empty
 
 Testing: -drive if=none,id=disk -device ide-hd,drive=disk
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: -device ide-hd,drive=disk: Device needs media, but drive is empty
+(qemu) QEMU_PROG: -device ide-hd,drive=disk: error: Device needs media, but drive is empty
 
 Testing: -drive if=none,id=disk -device lsi53c895a -device scsi-disk,drive=disk
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) QEMU_PROG: -device scsi-disk,drive=disk: warning: 'scsi-disk' is deprecated, please use 'scsi-hd' or 'scsi-cd' instead
-QEMU_PROG: -device scsi-disk,drive=disk: Device needs media, but drive is empty
+QEMU_PROG: -device scsi-disk,drive=disk: error: Device needs media, but drive is empty
 
 Testing: -drive if=none,id=disk -device lsi53c895a -device scsi-hd,drive=disk
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: -device scsi-hd,drive=disk: Device needs media, but drive is empty
+(qemu) QEMU_PROG: -device scsi-hd,drive=disk: error: Device needs media, but drive is empty
 
 
 === Attach to node in non-default iothread ===
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device ide-hd,drive=disk,share-rw=on
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: -device ide-hd,drive=disk,share-rw=on: Cannot change iothread of active block backend
+(qemu) QEMU_PROG: -device ide-hd,drive=disk,share-rw=on: error: Cannot change iothread of active block backend
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-blk-pci,drive=disk,share-rw=on
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: -device virtio-blk-pci,drive=disk,share-rw=on: Cannot change iothread of active block backend
+(qemu) QEMU_PROG: -device virtio-blk-pci,drive=disk,share-rw=on: error: Cannot change iothread of active block backend
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device lsi53c895a,id=lsi0 -device scsi-hd,bus=lsi0.0,drive=disk,share-rw=on
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: -device scsi-hd,bus=lsi0.0,drive=disk,share-rw=on: HBA does not support iothreads
+(qemu) QEMU_PROG: -device scsi-hd,bus=lsi0.0,drive=disk,share-rw=on: error: HBA does not support iothreads
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-scsi,id=virtio-scsi1 -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on: Cannot change iothread of active block backend
+(qemu) QEMU_PROG: -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on: error: Cannot change iothread of active block backend
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-blk-pci,drive=disk,iohtread=iothread0,share-rw=on
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: -device virtio-blk-pci,drive=disk,iohtread=iothread0,share-rw=on: Cannot change iothread of active block backend
+(qemu) QEMU_PROG: -device virtio-blk-pci,drive=disk,iohtread=iothread0,share-rw=on: error: Cannot change iothread of active block backend
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-scsi,id=virtio-scsi1,iothread=thread0 -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on
 QEMU X.Y.Z monitor - type 'help' for more information
@@ -214,7 +214,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=ide,readonly=on
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: Initialization of device ide-hd failed: Block node is read-only
+(qemu) QEMU_PROG: error: Initialization of device ide-hd failed: Block node is read-only
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=virtio,readonly=on
 QEMU X.Y.Z monitor - type 'help' for more information
@@ -231,11 +231,11 @@ QEMU X.Y.Z monitor - type 'help' for more information
 Testing: -drive file=TEST_DIR/t.qcow2,if=none,id=disk,readonly=on -device ide-drive,drive=disk
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) QEMU_PROG: -device ide-drive,drive=disk: warning: 'ide-drive' is deprecated, please use 'ide-hd' or 'ide-cd' instead
-QEMU_PROG: -device ide-drive,drive=disk: Block node is read-only
+QEMU_PROG: -device ide-drive,drive=disk: error: Block node is read-only
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=none,id=disk,readonly=on -device ide-hd,drive=disk
 QEMU X.Y.Z monitor - type 'help' for more information
-(qemu) QEMU_PROG: -device ide-hd,drive=disk: Block node is read-only
+(qemu) QEMU_PROG: -device ide-hd,drive=disk: error: Block node is read-only
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=none,id=disk,readonly=on -device lsi53c895a -device scsi-disk,drive=disk
 QEMU X.Y.Z monitor - type 'help' for more information
@@ -270,7 +270,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) quit
 
 Testing: -drive driver=null-co,cache=invalid_value
-QEMU_PROG: -drive driver=null-co,cache=invalid_value: invalid cache option
+QEMU_PROG: -drive driver=null-co,cache=invalid_value: error: invalid cache option
 
 Testing: -drive file=TEST_DIR/t.qcow2,cache=writeback,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
 QEMU X.Y.Z monitor - type 'help' for more information
@@ -333,7 +333,7 @@ backing-file: TEST_DIR/t.qcow2.base (file, read-only)
 (qemu) quit
 
 Testing: -drive file=TEST_DIR/t.qcow2,cache=invalid_value,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0 -nodefaults
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,cache=invalid_value,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0: invalid cache option
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,cache=invalid_value,backing.file.filename=TEST_DIR/t.qcow2.base,backing.cache.no-flush=on,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,if=none,id=drive0: error: invalid cache option
 
 
 === Specifying the protocol layer ===
@@ -346,94 +346,94 @@ QEMU X.Y.Z monitor - type 'help' for more information
 === Leaving out required options ===
 
 Testing: -drive driver=file
-QEMU_PROG: -drive driver=file: The 'file' block driver requires a file name
+QEMU_PROG: -drive driver=file: error: The 'file' block driver requires a file name
 
 Testing: -drive driver=file,filename=
-QEMU_PROG: -drive driver=file,filename=: The 'file' block driver requires a file name
+QEMU_PROG: -drive driver=file,filename=: error: The 'file' block driver requires a file name
 
 Testing: -drive driver=nbd
-QEMU_PROG: -drive driver=nbd: NBD server address missing
+QEMU_PROG: -drive driver=nbd: error: NBD server address missing
 
 Testing: -drive driver=raw
-QEMU_PROG: -drive driver=raw: A block device must be specified for "file"
+QEMU_PROG: -drive driver=raw: error: A block device must be specified for "file"
 
 Testing: -drive file.driver=file
-QEMU_PROG: -drive file.driver=file: The 'file' block driver requires a file name
+QEMU_PROG: -drive file.driver=file: error: The 'file' block driver requires a file name
 
 Testing: -drive file.driver=nbd
-QEMU_PROG: -drive file.driver=nbd: NBD server address missing
+QEMU_PROG: -drive file.driver=nbd: error: NBD server address missing
 
 Testing: -drive file.driver=raw
-QEMU_PROG: -drive file.driver=raw: A block device must be specified for "file"
+QEMU_PROG: -drive file.driver=raw: error: A block device must be specified for "file"
 
 Testing: -drive foo=bar
-QEMU_PROG: -drive foo=bar: Must specify either driver or file
+QEMU_PROG: -drive foo=bar: error: Must specify either driver or file
 
 
 === Specifying both an option and its legacy alias ===
 
 Testing: -drive file=TEST_DIR/t.qcow2,iops=1234,throttling.iops-total=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops=1234,throttling.iops-total=5678: 'throttling.iops-total' and its alias 'iops' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops=1234,throttling.iops-total=5678: error: 'throttling.iops-total' and its alias 'iops' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,iops_rd=1234,throttling.iops-read=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_rd=1234,throttling.iops-read=5678: 'throttling.iops-read' and its alias 'iops_rd' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_rd=1234,throttling.iops-read=5678: error: 'throttling.iops-read' and its alias 'iops_rd' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,iops_wr=1234,throttling.iops-write=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_wr=1234,throttling.iops-write=5678: 'throttling.iops-write' and its alias 'iops_wr' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_wr=1234,throttling.iops-write=5678: error: 'throttling.iops-write' and its alias 'iops_wr' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps=1234,throttling.bps-total=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps=1234,throttling.bps-total=5678: 'throttling.bps-total' and its alias 'bps' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps=1234,throttling.bps-total=5678: error: 'throttling.bps-total' and its alias 'bps' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps_rd=1234,throttling.bps-read=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_rd=1234,throttling.bps-read=5678: 'throttling.bps-read' and its alias 'bps_rd' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_rd=1234,throttling.bps-read=5678: error: 'throttling.bps-read' and its alias 'bps_rd' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps_wr=1234,throttling.bps-write=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_wr=1234,throttling.bps-write=5678: 'throttling.bps-write' and its alias 'bps_wr' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_wr=1234,throttling.bps-write=5678: error: 'throttling.bps-write' and its alias 'bps_wr' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,iops_max=1234,throttling.iops-total-max=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_max=1234,throttling.iops-total-max=5678: 'throttling.iops-total-max' and its alias 'iops_max' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_max=1234,throttling.iops-total-max=5678: error: 'throttling.iops-total-max' and its alias 'iops_max' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,iops_rd_max=1234,throttling.iops-read-max=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_rd_max=1234,throttling.iops-read-max=5678: 'throttling.iops-read-max' and its alias 'iops_rd_max' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_rd_max=1234,throttling.iops-read-max=5678: error: 'throttling.iops-read-max' and its alias 'iops_rd_max' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,iops_wr_max=1234,throttling.iops-write-max=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_wr_max=1234,throttling.iops-write-max=5678: 'throttling.iops-write-max' and its alias 'iops_wr_max' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_wr_max=1234,throttling.iops-write-max=5678: error: 'throttling.iops-write-max' and its alias 'iops_wr_max' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps_max=1234,throttling.bps-total-max=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_max=1234,throttling.bps-total-max=5678: 'throttling.bps-total-max' and its alias 'bps_max' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_max=1234,throttling.bps-total-max=5678: error: 'throttling.bps-total-max' and its alias 'bps_max' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps_rd_max=1234,throttling.bps-read-max=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_rd_max=1234,throttling.bps-read-max=5678: 'throttling.bps-read-max' and its alias 'bps_rd_max' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_rd_max=1234,throttling.bps-read-max=5678: error: 'throttling.bps-read-max' and its alias 'bps_rd_max' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps_wr_max=1234,throttling.bps-write-max=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_wr_max=1234,throttling.bps-write-max=5678: 'throttling.bps-write-max' and its alias 'bps_wr_max' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_wr_max=1234,throttling.bps-write-max=5678: error: 'throttling.bps-write-max' and its alias 'bps_wr_max' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,iops_size=1234,throttling.iops-size=5678
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_size=1234,throttling.iops-size=5678: 'throttling.iops-size' and its alias 'iops_size' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops_size=1234,throttling.iops-size=5678: error: 'throttling.iops-size' and its alias 'iops_size' can't be used at the same time
 
 Testing: -drive file=TEST_DIR/t.qcow2,readonly=on,read-only=off
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,readonly=on,read-only=off: 'read-only' and its alias 'readonly' can't be used at the same time
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,readonly=on,read-only=off: error: 'read-only' and its alias 'readonly' can't be used at the same time
 
 
 === Catching negative/large throttling values ===
 
 Testing: -drive file=TEST_DIR/t.qcow2,iops=-1
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops=-1: bps/iops/max values must be within [0, 1000000000000000]
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,iops=-1: error: bps/iops/max values must be within [0, 1000000000000000]
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps=-2
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps=-2: bps/iops/max values must be within [0, 1000000000000000]
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps=-2: error: bps/iops/max values must be within [0, 1000000000000000]
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps_rd=-3
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_rd=-3: bps/iops/max values must be within [0, 1000000000000000]
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_rd=-3: error: bps/iops/max values must be within [0, 1000000000000000]
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps_rd_max=-3
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_rd_max=-3: bps/iops/max values must be within [0, 1000000000000000]
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps_rd_max=-3: error: bps/iops/max values must be within [0, 1000000000000000]
 
 Testing: -drive file=TEST_DIR/t.qcow2,throttling.iops-total=-4
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,throttling.iops-total=-4: bps/iops/max values must be within [0, 1000000000000000]
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,throttling.iops-total=-4: error: bps/iops/max values must be within [0, 1000000000000000]
 
 Testing: -drive file=TEST_DIR/t.qcow2,throttling.bps-total=-5
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,throttling.bps-total=-5: bps/iops/max values must be within [0, 1000000000000000]
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,throttling.bps-total=-5: error: bps/iops/max values must be within [0, 1000000000000000]
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps=0
 QEMU X.Y.Z monitor - type 'help' for more information
@@ -448,22 +448,22 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) quit
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps=1000000000000001
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps=1000000000000001: bps/iops/max values must be within [0, 1000000000000000]
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps=1000000000000001: error: bps/iops/max values must be within [0, 1000000000000000]
 
 Testing: -drive file=TEST_DIR/t.qcow2,bps=9999999999999999
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps=9999999999999999: bps/iops/max values must be within [0, 1000000000000000]
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,bps=9999999999999999: error: bps/iops/max values must be within [0, 1000000000000000]
 
 
 === Parsing protocol from file name ===
 
 Testing: -hda foo:bar
-QEMU_PROG: -hda foo:bar: Unknown protocol 'foo'
+QEMU_PROG: -hda foo:bar: error: Unknown protocol 'foo'
 
 Testing: -drive file=foo:bar
-QEMU_PROG: -drive file=foo:bar: Unknown protocol 'foo'
+QEMU_PROG: -drive file=foo:bar: error: Unknown protocol 'foo'
 
 Testing: -drive file.filename=foo:bar
-QEMU_PROG: -drive file.filename=foo:bar: Could not open 'foo:bar': No such file or directory
+QEMU_PROG: -drive file.filename=foo:bar: error: Could not open 'foo:bar': No such file or directory
 
 Testing: -hda file:TEST_DIR/t.qcow2
 QEMU X.Y.Z monitor - type 'help' for more information
@@ -474,7 +474,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) quit
 
 Testing: -drive file.filename=file:TEST_DIR/t.qcow2
-QEMU_PROG: -drive file.filename=file:TEST_DIR/t.qcow2: Could not open 'file:TEST_DIR/t.qcow2': No such file or directory
+QEMU_PROG: -drive file.filename=file:TEST_DIR/t.qcow2: error: Could not open 'file:TEST_DIR/t.qcow2': No such file or directory
 
 
 === Snapshot mode ===
@@ -559,7 +559,7 @@ wrote 4096/4096 bytes at offset 0
 read 4096/4096 bytes at offset 0
 4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 Testing: -drive driver=null-co,snapshot=on
-QEMU_PROG: -drive driver=null-co,snapshot=on: Could not get temporary filename: No such file or directory
+QEMU_PROG: -drive driver=null-co,snapshot=on: error: Could not get temporary filename: No such file or directory
 
 Testing: -drive file=TEST_DIR/t.qcow2,snapshot=on,read-only=on,if=none,id=drive0
 QEMU X.Y.Z monitor - type 'help' for more information
diff --git a/tests/qemu-iotests/054.out b/tests/qemu-iotests/054.out
index e6ec430edd..7cddf38bc0 100644
--- a/tests/qemu-iotests/054.out
+++ b/tests/qemu-iotests/054.out
@@ -1,10 +1,10 @@
 QA output created by 054
 
 creating too large image (1 EB)
-qemu-img: TEST_DIR/t.IMGFMT: The image size is too large for file format 'IMGFMT' (try using a larger cluster size)
+qemu-img: error: TEST_DIR/t.IMGFMT: The image size is too large for file format 'IMGFMT' (try using a larger cluster size)
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1152921504606846976
 
 creating too large image (1 EB) using qcow2.py
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Image is too big
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Image is too big
 *** done
diff --git a/tests/qemu-iotests/060.out b/tests/qemu-iotests/060.out
index d27692a33c..1162a9372e 100644
--- a/tests/qemu-iotests/060.out
+++ b/tests/qemu-iotests/060.out
@@ -20,7 +20,7 @@ Format specific information:
     lazy refcounts: false
     refcount bits: 16
     corrupt: true
-qemu-io: can't open device TEST_DIR/t.IMGFMT: IMGFMT: Image is corrupt; cannot be opened read/write
+qemu-io: error: can't open device TEST_DIR/t.IMGFMT: IMGFMT: Image is corrupt; cannot be opened read/write
 no file open, try 'help open'
 read 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
@@ -132,7 +132,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 qcow2: Marking image as corrupt: L2 table offset 0x42a00 unaligned (L1 index: 0); further corruption events will be suppressed
-qemu-img: Failed to turn zero into data clusters: Input/output error
+qemu-img: error: Failed to turn zero into data clusters: Input/output error
 
 === Testing unaligned L2 entry ===
 
@@ -148,7 +148,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 qcow2: Marking image as corrupt: Cluster allocation offset 0x52a00 unaligned (L2 offset: 0x40000, L2 index: 0); further corruption events will be suppressed
-qemu-img: Failed to turn zero into data clusters: Input/output error
+qemu-img: error: Failed to turn zero into data clusters: Input/output error
 
 === Testing unaligned reftable entry ===
 
@@ -270,7 +270,7 @@ No errors were found on the image.
 === Testing zero refcount table size ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.IMGFMT: Image does not contain a reference count table
+qemu-io: error: can't open device TEST_DIR/t.IMGFMT: Image does not contain a reference count table
 ERROR cluster 0 refcount=0 reference=1
 ERROR cluster 3 refcount=0 reference=1
 Rebuilding refcount structure
@@ -299,7 +299,7 @@ Can't get refcount for cluster 2: Input/output error
 Can't get refcount for cluster 3: Input/output error
 Rebuilding refcount structure
 Repairing cluster 1 refcount=1 reference=0
-qemu-io: can't open device TEST_DIR/t.IMGFMT: Could not repair dirty image: Input/output error
+qemu-io: error: can't open device TEST_DIR/t.IMGFMT: Could not repair dirty image: Input/output error
 --- Repairing ---
 Leaked cluster 1 refcount=1 reference=0
 Repairing cluster 1 refcount=1 reference=0
@@ -350,7 +350,7 @@ Can't get refcount for cluster 5: Input/output error
 Can't get refcount for cluster 6: Input/output error
 Rebuilding refcount structure
 Repairing cluster 1 refcount=1 reference=0
-qemu-img: Check failed: No medium found
+qemu-img: error: Check failed: No medium found
 Leaked cluster 1 refcount=1 reference=0
 Repairing cluster 1 refcount=1 reference=0
 The following inconsistencies were found and repaired:
@@ -365,7 +365,7 @@ No errors were found on the image.
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 qcow2: Marking image as corrupt: Refblock at 0xffffff00000000 is not covered by the refcount structures; further corruption events will be suppressed
-qemu-img: Failed to discard unused refblocks: Input/output error
+qemu-img: error: Failed to discard unused refblocks: Input/output error
 --- Checking and retrying ---
 virtual size: 64 MiB (67108864 bytes)
 No errors were found on the image.
@@ -376,7 +376,7 @@ virtual size: 32 MiB (33554432 bytes)
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 qcow2: Marking image as corrupt: Refblock at 0x1000000000 is not covered by the refcount structures; further corruption events will be suppressed
-qemu-img: Failed to discard unused refblocks: Input/output error
+qemu-img: error: Failed to discard unused refblocks: Input/output error
 --- Checking and retrying ---
 virtual size: 64 MiB (67108864 bytes)
 No errors were found on the image.
@@ -387,7 +387,7 @@ virtual size: 32 MiB (33554432 bytes)
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 qcow2: Marking image as corrupt: Cannot get entry from refcount block cache: Offset 0x200 is unaligned; further corruption events will be suppressed
-qemu-img: Failed to discard unused refblocks: Input/output error
+qemu-img: error: Failed to discard unused refblocks: Input/output error
 --- Repairing ---
 Repairing refcount block 1 is outside image
 ERROR refcount block 2 is not cluster aligned; refcount table entry corrupted
@@ -397,7 +397,7 @@ Rebuilding refcount structure
 Repairing cluster 1 refcount=1 reference=0
 Repairing cluster 2 refcount=1 reference=0
 Repairing cluster 1048576 refcount=1 reference=0
-qemu-img: Check failed: No medium found
+qemu-img: error: Check failed: No medium found
 Leaked cluster 1 refcount=1 reference=0
 Leaked cluster 2 refcount=1 reference=0
 Leaked cluster 1048576 refcount=1 reference=0
diff --git a/tests/qemu-iotests/061.out b/tests/qemu-iotests/061.out
index 8b3091a412..06245c0f99 100644
--- a/tests/qemu-iotests/061.out
+++ b/tests/qemu-iotests/061.out
@@ -349,20 +349,20 @@ No errors were found on the image.
 === Testing invalid configurations ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-img: Lazy refcounts only supported with compatibility level 1.1 and above (use compat=1.1 or greater)
-qemu-img: Lazy refcounts only supported with compatibility level 1.1 and above (use compat=1.1 or greater)
-qemu-img: Unknown compatibility level 0.42
-qemu-img: Invalid parameter 'foo'
-qemu-img: Changing the cluster size is not supported
-qemu-img: Changing the encryption flag is not supported
-qemu-img: Cannot change preallocation mode
+qemu-img: error: Lazy refcounts only supported with compatibility level 1.1 and above (use compat=1.1 or greater)
+qemu-img: error: Lazy refcounts only supported with compatibility level 1.1 and above (use compat=1.1 or greater)
+qemu-img: error: Unknown compatibility level 0.42
+qemu-img: error: Invalid parameter 'foo'
+qemu-img: error: Changing the cluster size is not supported
+qemu-img: error: Changing the encryption flag is not supported
+qemu-img: error: Cannot change preallocation mode
 
 === Testing correct handling of unset value ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 Should work:
 Should not work:
-qemu-img: Changing the cluster size is not supported
+qemu-img: error: Changing the cluster size is not supported
 
 === Testing zero expansion on inactive clusters ===
 
@@ -484,7 +484,7 @@ No errors were found on the image.
 === Testing version downgrade with external data file ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data
-qemu-img: Cannot downgrade an image with a data file
+qemu-img: error: Cannot downgrade an image with a data file
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 64 MiB (67108864 bytes)
@@ -501,10 +501,10 @@ No errors were found on the image.
 === Try changing the external data file ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-img: data-file can only be set for images that use an external data file
+qemu-img: error: data-file can only be set for images that use an external data file
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 data_file=TEST_DIR/t.IMGFMT.data
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Could not open 'foo': No such file or directory
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Could not open 'foo': No such file or directory
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 64 MiB (67108864 bytes)
@@ -517,7 +517,7 @@ Format specific information:
     data file raw: false
     corrupt: false
 
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': 'data-file' is required for this image
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': 'data-file' is required for this image
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 64 MiB (67108864 bytes)
@@ -556,7 +556,7 @@ Format specific information:
     data file raw: false
     corrupt: false
 No errors were found on the image.
-qemu-img: data-file-raw cannot be set on existing images
+qemu-img: error: data-file-raw cannot be set on existing images
 image: TEST_DIR/t.IMGFMT
 file format: IMGFMT
 virtual size: 64 MiB (67108864 bytes)
diff --git a/tests/qemu-iotests/069.out b/tests/qemu-iotests/069.out
index c78e8c2b72..96e3ff2dd6 100644
--- a/tests/qemu-iotests/069.out
+++ b/tests/qemu-iotests/069.out
@@ -4,5 +4,5 @@ QA output created by 069
 
 Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=131072
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=131072 backing_file=TEST_DIR/t.IMGFMT.base
-qemu-io: can't open device TEST_DIR/t.IMGFMT: Could not open backing file: Could not open 'TEST_DIR/t.IMGFMT.base': No such file or directory
+qemu-io: error: can't open device TEST_DIR/t.IMGFMT: Could not open backing file: Could not open 'TEST_DIR/t.IMGFMT.base': No such file or directory
 *** done
diff --git a/tests/qemu-iotests/071.out b/tests/qemu-iotests/071.out
index bca0c02f5c..30e5266583 100644
--- a/tests/qemu-iotests/071.out
+++ b/tests/qemu-iotests/071.out
@@ -86,7 +86,7 @@ read failed: Input/output error
 {"return": ""}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "SHUTDOWN", "data": {"guest": false, "reason": "host-qmp-quit"}}
-QEMU_PROG: Failed to flush the L2 table cache: Input/output error
-QEMU_PROG: Failed to flush the refcount block cache: Input/output error
+QEMU_PROG: error: Failed to flush the L2 table cache: Input/output error
+QEMU_PROG: error: Failed to flush the refcount block cache: Input/output error
 
 *** done
diff --git a/tests/qemu-iotests/074.out b/tests/qemu-iotests/074.out
index ede66c3f81..cd8bcb3b67 100644
--- a/tests/qemu-iotests/074.out
+++ b/tests/qemu-iotests/074.out
@@ -3,14 +3,14 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 === IO: pattern 102
 wrote 512/512 bytes at offset 512
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Error while reading offset 0 of blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
+qemu-img: error: Error while reading offset 0 of blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
 4
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
 Formatting 'TEST_DIR/t.IMGFMT.2', fmt=IMGFMT size=0
 === IO: pattern 102
 wrote 512/512 bytes at offset 512
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Error while reading offset 0 of blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
+qemu-img: error: Error while reading offset 0 of blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
 Warning: Image size mismatch!
 4
 Cleanup
diff --git a/tests/qemu-iotests/079.out b/tests/qemu-iotests/079.out
index aab922fb36..e3b2cf0ba1 100644
--- a/tests/qemu-iotests/079.out
+++ b/tests/qemu-iotests/079.out
@@ -9,6 +9,6 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation=metadat
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation=metadata
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation=metadata
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation=metadata
-qemu-img: TEST_DIR/t.IMGFMT: Cluster size must be a power of two between 512 and 2048k
+qemu-img: error: TEST_DIR/t.IMGFMT: Cluster size must be a power of two between 512 and 2048k
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=4294967296 preallocation=metadata
 *** done
diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out
index 45ab01db8e..b9f32f27d4 100644
--- a/tests/qemu-iotests/080.out
+++ b/tests/qemu-iotests/080.out
@@ -2,75 +2,75 @@ QA output created by 080
 
 == Huge header size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
-qemu-io: can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
+qemu-io: error: can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
+qemu-io: error: can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
 
 == Huge unknown header extension ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Invalid backing file offset
-qemu-io: can't open device TEST_DIR/t.qcow2: Header extension too large
-qemu-io: can't open device TEST_DIR/t.qcow2: Header extension too large
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Invalid backing file offset
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Header extension too large
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Header extension too large
 
 == Huge refcount table size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table too large
-qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table too large
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Reference count table too large
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Reference count table too large
 
 == Misaligned refcount table ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table offset invalid
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Reference count table offset invalid
 
 == Huge refcount offset ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Reference count table offset invalid
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Reference count table offset invalid
 
 == Invalid snapshot table ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Snapshot table too large
-qemu-io: can't open device TEST_DIR/t.qcow2: Snapshot table too large
-qemu-io: can't open device TEST_DIR/t.qcow2: Snapshot table offset invalid
-qemu-io: can't open device TEST_DIR/t.qcow2: Snapshot table offset invalid
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Snapshot table too large
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Snapshot table too large
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Snapshot table offset invalid
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Snapshot table offset invalid
 
 == Hitting snapshot table size limit ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-img: Could not create snapshot 'test': -27 (File too large)
+qemu-img: error: Could not create snapshot 'test': -27 (File too large)
 read 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == Invalid L1 table ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table too large
-qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table too large
-qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table offset invalid
-qemu-io: can't open device TEST_DIR/t.qcow2: Active L1 table offset invalid
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Active L1 table too large
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Active L1 table too large
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Active L1 table offset invalid
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Active L1 table offset invalid
 
 == Invalid L1 table (with internal snapshot in the image) ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': L1 table is too small
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': L1 table is too small
 
 == Invalid backing file size ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: Backing file name too long
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Backing file name too long
 
 == Invalid L2 entry (huge physical offset) ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Could not create snapshot 'test': -27 (File too large)
-qemu-img: Could not create snapshot 'test': -11 (Resource temporarily unavailable)
+qemu-img: error: Could not create snapshot 'test': -27 (File too large)
+qemu-img: error: Could not create snapshot 'test': -11 (Resource temporarily unavailable)
 
 == Invalid snapshot L1 table offset ==
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Failed to load snapshot: Snapshot L1 table offset invalid
-qemu-img: Snapshot L1 table offset invalid
-qemu-img: Failed to turn zero into data clusters: Invalid argument
-qemu-io: Failed to flush the refcount block cache: Invalid argument
+qemu-img: error: Failed to load snapshot: Snapshot L1 table offset invalid
+qemu-img: error: Snapshot L1 table offset invalid
+qemu-img: error: Failed to turn zero into data clusters: Invalid argument
+qemu-io: error: Failed to flush the refcount block cache: Invalid argument
 write failed: Invalid argument
-qemu-img: Snapshot L1 table offset invalid
-qemu-img: Could not apply snapshot 'test': Failed to load snapshot: Invalid argument
-qemu-img: Could not delete snapshot 'test': Snapshot L1 table offset invalid
+qemu-img: error: Snapshot L1 table offset invalid
+qemu-img: error: Could not apply snapshot 'test': Failed to load snapshot: Invalid argument
+qemu-img: error: Could not delete snapshot 'test': Snapshot L1 table offset invalid
 ERROR snapshot 1 (test) l1_offset=0x400200: L1 table is not cluster aligned; snapshot table entry corrupted
 Leaked cluster 4 refcount=2 reference=1
 Leaked cluster 5 refcount=2 reference=1
@@ -86,14 +86,14 @@ This means waste of disk space, but no harm to data.
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Failed to load snapshot: Snapshot L1 table too large
-qemu-img: Snapshot L1 table too large
-qemu-img: Failed to turn zero into data clusters: File too large
-qemu-io: Failed to flush the refcount block cache: File too large
+qemu-img: error: Failed to load snapshot: Snapshot L1 table too large
+qemu-img: error: Snapshot L1 table too large
+qemu-img: error: Failed to turn zero into data clusters: File too large
+qemu-io: error: Failed to flush the refcount block cache: File too large
 write failed: File too large
-qemu-img: Snapshot L1 table too large
-qemu-img: Could not apply snapshot 'test': Failed to load snapshot: File too large
-qemu-img: Could not delete snapshot 'test': Snapshot L1 table too large
+qemu-img: error: Snapshot L1 table too large
+qemu-img: error: Could not apply snapshot 'test': Failed to load snapshot: File too large
+qemu-img: error: Could not delete snapshot 'test': Snapshot L1 table too large
 ERROR snapshot 1 (test) l1_size=0x10000000: L1 table is too large; snapshot table entry corrupted
 Leaked cluster 4 refcount=2 reference=1
 Leaked cluster 5 refcount=2 reference=1
diff --git a/tests/qemu-iotests/081.out b/tests/qemu-iotests/081.out
index 04091b64e5..129a628f87 100644
--- a/tests/qemu-iotests/081.out
+++ b/tests/qemu-iotests/081.out
@@ -70,7 +70,7 @@ read 10485760/10485760 bytes at offset 0
 10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == checking the blkverify mode with invalid settings ==
-qemu-io: can't open: blkverify=on can only be set if there are exactly two files and vote-threshold is 2
+qemu-io: error: can't open: blkverify=on can only be set if there are exactly two files and vote-threshold is 2
 
 == dynamically adding a child to a quorum ==
 Testing:
diff --git a/tests/qemu-iotests/082.out b/tests/qemu-iotests/082.out
index 9d4ed4dc9d..8391e485da 100644
--- a/tests/qemu-iotests/082.out
+++ b/tests/qemu-iotests/082.out
@@ -233,13 +233,13 @@ Testing: create -f qcow2 -u -o backing_file=TEST_DIR/t.qcow2,,? TEST_DIR/t.qcow2
 Formatting 'TEST_DIR/t.qcow2', fmt=qcow2 size=134217728 backing_file=TEST_DIR/t.qcow2,,? cluster_size=65536 lazy_refcounts=off refcount_bits=16
 
 Testing: create -f qcow2 -o backing_file=TEST_DIR/t.qcow2, -o help TEST_DIR/t.qcow2 128M
-qemu-img: Invalid option list: backing_file=TEST_DIR/t.qcow2,
+qemu-img: error: Invalid option list: backing_file=TEST_DIR/t.qcow2,
 
 Testing: create -f qcow2 -o backing_file=TEST_DIR/t.qcow2 -o ,help TEST_DIR/t.qcow2 128M
-qemu-img: Invalid option list: ,help
+qemu-img: error: Invalid option list: ,help
 
 Testing: create -f qcow2 -o backing_file=TEST_DIR/t.qcow2 -o ,, -o help TEST_DIR/t.qcow2 128M
-qemu-img: Invalid option list: ,,
+qemu-img: error: Invalid option list: ,,
 
 Testing: create -f qcow2 -o help
 Supported qcow2 options:
@@ -274,7 +274,7 @@ The protocol level may support further options.
 Specify the target filename to include those options.
 
 Testing: create -f bochs -o help
-qemu-img: Format driver 'bochs' does not support image creation
+qemu-img: error: Format driver 'bochs' does not support image creation
 
 === convert: Options specified more than once ===
 
@@ -507,19 +507,19 @@ Supported options:
   size=<size>            - Virtual disk size
 
 Testing: convert -O qcow2 -o backing_file=TEST_DIR/t.qcow2,,help TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
-qemu-img: Could not open 'TEST_DIR/t.qcow2.base': Could not open backing file: Could not open 'TEST_DIR/t.qcow2,help': No such file or directory
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2.base': Could not open backing file: Could not open 'TEST_DIR/t.qcow2,help': No such file or directory
 
 Testing: convert -O qcow2 -o backing_file=TEST_DIR/t.qcow2,,? TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
-qemu-img: Could not open 'TEST_DIR/t.qcow2.base': Could not open backing file: Could not open 'TEST_DIR/t.qcow2,?': No such file or directory
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2.base': Could not open backing file: Could not open 'TEST_DIR/t.qcow2,?': No such file or directory
 
 Testing: convert -O qcow2 -o backing_file=TEST_DIR/t.qcow2, -o help TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
-qemu-img: Invalid option list: backing_file=TEST_DIR/t.qcow2,
+qemu-img: error: Invalid option list: backing_file=TEST_DIR/t.qcow2,
 
 Testing: convert -O qcow2 -o backing_file=TEST_DIR/t.qcow2 -o ,help TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
-qemu-img: Invalid option list: ,help
+qemu-img: error: Invalid option list: ,help
 
 Testing: convert -O qcow2 -o backing_file=TEST_DIR/t.qcow2 -o ,, -o help TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.base
-qemu-img: Invalid option list: ,,
+qemu-img: error: Invalid option list: ,,
 
 Testing: convert -O qcow2 -o help
 Supported qcow2 options:
@@ -554,21 +554,21 @@ The protocol level may support further options.
 Specify the target filename to include those options.
 
 Testing: convert -O bochs -o help
-qemu-img: Format driver 'bochs' does not support image creation
+qemu-img: error: Format driver 'bochs' does not support image creation
 
 === convert: -C and other options ===
 
 Testing: convert -C -S 4k -O qcow2 TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.target
-qemu-img: Cannot enable copy offloading when -S is used
+qemu-img: error: Cannot enable copy offloading when -S is used
 
 Testing: convert -C -S 8k -O qcow2 TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.target
-qemu-img: Cannot enable copy offloading when -S is used
+qemu-img: error: Cannot enable copy offloading when -S is used
 
 Testing: convert -C -c -O qcow2 TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.target
-qemu-img: Cannot enable copy offloading when -c is used
+qemu-img: error: Cannot enable copy offloading when -c is used
 
 Testing: convert -C --salvage -O qcow2 TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.target
-qemu-img: Cannot use copy offloading in salvaging mode
+qemu-img: error: Cannot use copy offloading in salvaging mode
 
 === amend: Options specified more than once ===
 
@@ -814,13 +814,13 @@ Testing: amend -f qcow2 -o backing_file=TEST_DIR/t.qcow2,,? TEST_DIR/t.qcow2
 Testing: rebase -u -b  -f qcow2 TEST_DIR/t.qcow2
 
 Testing: amend -f qcow2 -o backing_file=TEST_DIR/t.qcow2, -o help TEST_DIR/t.qcow2
-qemu-img: Invalid option list: backing_file=TEST_DIR/t.qcow2,
+qemu-img: error: Invalid option list: backing_file=TEST_DIR/t.qcow2,
 
 Testing: amend -f qcow2 -o backing_file=TEST_DIR/t.qcow2 -o ,help TEST_DIR/t.qcow2
-qemu-img: Invalid option list: ,help
+qemu-img: error: Invalid option list: ,help
 
 Testing: amend -f qcow2 -o backing_file=TEST_DIR/t.qcow2 -o ,, -o help TEST_DIR/t.qcow2
-qemu-img: Invalid option list: ,,
+qemu-img: error: Invalid option list: ,,
 
 Testing: amend -f qcow2 -o help
 Creation options for 'qcow2':
@@ -847,8 +847,8 @@ Creation options for 'qcow2':
 Note that not all of these options may be amendable.
 
 Testing: amend -o help
-qemu-img: Expecting one image file name
+qemu-img: error: Expecting one image file name
 
 Testing: amend -f bochs -o help
-qemu-img: Format driver 'bochs' does not support option amendment
+qemu-img: error: Format driver 'bochs' does not support option amendment
 *** done
diff --git a/tests/qemu-iotests/083.out b/tests/qemu-iotests/083.out
index 2090ee693c..696fb5ff75 100644
--- a/tests/qemu-iotests/083.out
+++ b/tests/qemu-iotests/083.out
@@ -1,43 +1,43 @@
 QA output created by 083
 === Check disconnect before neg1 ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect after neg1 ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect 8 neg1 ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect 16 neg1 ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect before export ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect after export ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect 4 export ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect 12 export ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect 16 export ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect before neg2 ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect after neg2 ===
 
@@ -45,11 +45,11 @@ read failed: Input/output error
 
 === Check disconnect 8 neg2 ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect 10 neg2 ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/foo
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/foo
 
 === Check disconnect before request ===
 
@@ -86,23 +86,23 @@ read 512/512 bytes at offset 0
 
 === Check disconnect before neg-classic ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/
 
 === Check disconnect 8 neg-classic ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/
 
 === Check disconnect 16 neg-classic ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/
 
 === Check disconnect 24 neg-classic ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/
 
 === Check disconnect 28 neg-classic ===
 
-qemu-io: can't open device nbd+tcp://127.0.0.1:PORT/
+qemu-io: error: can't open device nbd+tcp://127.0.0.1:PORT/
 
 === Check disconnect after neg-classic ===
 
@@ -110,43 +110,43 @@ read failed: Input/output error
 
 === Check disconnect before neg1 ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect after neg1 ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect 8 neg1 ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect 16 neg1 ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect before export ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect after export ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect 4 export ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect 12 export ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect 16 export ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect before neg2 ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect after neg2 ===
 
@@ -154,11 +154,11 @@ read failed: Input/output error
 
 === Check disconnect 8 neg2 ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect 10 neg2 ===
 
-qemu-io: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///foo?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect before request ===
 
@@ -195,23 +195,23 @@ read 512/512 bytes at offset 0
 
 === Check disconnect before neg-classic ===
 
-qemu-io: can't open device nbd+unix:///?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect 8 neg-classic ===
 
-qemu-io: can't open device nbd+unix:///?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect 16 neg-classic ===
 
-qemu-io: can't open device nbd+unix:///?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect 24 neg-classic ===
 
-qemu-io: can't open device nbd+unix:///?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect 28 neg-classic ===
 
-qemu-io: can't open device nbd+unix:///?socket=SOCK_DIR/nbd.sock
+qemu-io: error: can't open device nbd+unix:///?socket=SOCK_DIR/nbd.sock
 
 === Check disconnect after neg-classic ===
 
diff --git a/tests/qemu-iotests/098.out b/tests/qemu-iotests/098.out
index 7634d0e8b0..d22713052d 100644
--- a/tests/qemu-iotests/098.out
+++ b/tests/qemu-iotests/098.out
@@ -6,7 +6,7 @@ Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Could not empty blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
+qemu-img: error: Could not empty blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
 No errors were found on the image.
 
 === empty_image_prepare ===
@@ -15,7 +15,7 @@ Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Could not empty blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
+qemu-img: error: Could not empty blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
 Leaked cluster 4 refcount=1 reference=0
 Leaked cluster 5 refcount=1 reference=0
 Repairing cluster 4 refcount=1 reference=0
@@ -28,7 +28,7 @@ Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Could not empty blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
+qemu-img: error: Could not empty blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
 ERROR cluster 0 refcount=0 reference=1
 ERROR cluster 1 refcount=0 reference=1
 ERROR cluster 3 refcount=0 reference=1
@@ -42,7 +42,7 @@ Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=67108864
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t.IMGFMT.base
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Could not empty blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
+qemu-img: error: Could not empty blkdebug:TEST_DIR/blkdebug.conf:TEST_DIR/t.IMGFMT: Input/output error
 ERROR cluster 0 refcount=0 reference=1
 ERROR cluster 1 refcount=0 reference=1
 ERROR cluster 3 refcount=0 reference=1
diff --git a/tests/qemu-iotests/103.out b/tests/qemu-iotests/103.out
index 16704cf499..983212f9cf 100644
--- a/tests/qemu-iotests/103.out
+++ b/tests/qemu-iotests/103.out
@@ -5,13 +5,13 @@ wrote 65536/65536 bytes at offset 0
 
 === Testing invalid option combinations ===
 
-qemu-io: can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
-qemu-io: can't open device TEST_DIR/t.IMGFMT: l2-cache-size may not exceed cache-size
-qemu-io: can't open device TEST_DIR/t.IMGFMT: refcount-cache-size may not exceed cache-size
-qemu-io: can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
-qemu-io: can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
-qemu-io: can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
-qemu-io: can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
+qemu-io: error: can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
+qemu-io: error: can't open device TEST_DIR/t.IMGFMT: l2-cache-size may not exceed cache-size
+qemu-io: error: can't open device TEST_DIR/t.IMGFMT: refcount-cache-size may not exceed cache-size
+qemu-io: error: can't open device TEST_DIR/t.IMGFMT: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
+qemu-io: error: can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
+qemu-io: error: can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
+qemu-io: error: can't open device TEST_DIR/t.IMGFMT: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
 
 === Testing valid option combinations ===
 
diff --git a/tests/qemu-iotests/106.out b/tests/qemu-iotests/106.out
index c459957660..3c1fbcbb70 100644
--- a/tests/qemu-iotests/106.out
+++ b/tests/qemu-iotests/106.out
@@ -40,10 +40,10 @@ Image resized.
 === Testing image shrinking ===
 
 --- growth_mode=falloc ---
-qemu-img: Preallocation can only be used for growing images
+qemu-img: error: Preallocation can only be used for growing images
 
 --- growth_mode=full ---
-qemu-img: Preallocation can only be used for growing images
+qemu-img: error: Preallocation can only be used for growing images
 
 --- growth_mode=off ---
 Image resized.
diff --git a/tests/qemu-iotests/111.out b/tests/qemu-iotests/111.out
index 5279c462fc..fc13d8a635 100644
--- a/tests/qemu-iotests/111.out
+++ b/tests/qemu-iotests/111.out
@@ -1,4 +1,4 @@
 QA output created by 111
-qemu-img: TEST_DIR/t.IMGFMT: Could not open 'TEST_DIR/t.IMGFMT.inexistent': No such file or directory
+qemu-img: error: TEST_DIR/t.IMGFMT: Could not open 'TEST_DIR/t.IMGFMT.inexistent': No such file or directory
 Could not open backing image to determine size.
 *** done
diff --git a/tests/qemu-iotests/112.out b/tests/qemu-iotests/112.out
index ae0318cabe..ff5c3e8cfb 100644
--- a/tests/qemu-iotests/112.out
+++ b/tests/qemu-iotests/112.out
@@ -2,13 +2,13 @@ QA output created by 112
 
 === refcount_bits limits ===
 
-qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
+qemu-img: error: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
+qemu-img: error: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 refcount_bits=-1
-qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
+qemu-img: error: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-img: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
+qemu-img: error: TEST_DIR/t.IMGFMT: Refcount width must be a power of two and may not exceed 64 bits
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 refcount bits: 1
@@ -21,9 +21,9 @@ refcount bits: 16
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 refcount bits: 16
-qemu-img: TEST_DIR/t.IMGFMT: Different refcount widths than 16 bits require compatibility level 1.1 or above (use version=v3 or greater)
+qemu-img: error: TEST_DIR/t.IMGFMT: Different refcount widths than 16 bits require compatibility level 1.1 or above (use version=v3 or greater)
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-img: TEST_DIR/t.IMGFMT: Different refcount widths than 16 bits require compatibility level 1.1 or above (use version=v3 or greater)
+qemu-img: error: TEST_DIR/t.IMGFMT: Different refcount widths than 16 bits require compatibility level 1.1 or above (use version=v3 or greater)
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 
 === Snapshot limit on refcount_bits=1 ===
@@ -32,7 +32,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 refcount bits: 1
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Could not create snapshot 'foo': -22 (Invalid argument)
+qemu-img: error: Could not create snapshot 'foo': -22 (Invalid argument)
 Leaked cluster 6 refcount=1 reference=0
 
 1 leaked clusters were found on the image.
@@ -44,7 +44,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 refcount bits: 2
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Could not create snapshot 'baz': -22 (Invalid argument)
+qemu-img: error: Could not create snapshot 'baz': -22 (Invalid argument)
 Leaked cluster 7 refcount=1 reference=0
 
 1 leaked clusters were found on the image.
@@ -75,7 +75,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 refcount bits: 64
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Could not create snapshot 'foo': -22 (Invalid argument)
+qemu-img: error: Could not create snapshot 'foo': -22 (Invalid argument)
 Leaked cluster 5 refcount=18446744073709551615 reference=1
 Leaked cluster 6 refcount=1 reference=0
 
@@ -98,19 +98,19 @@ refcount bits: 64
 
 === Amend to compat=0.10 ===
 
-qemu-img: compat=0.10 requires refcount_bits=16
+qemu-img: error: compat=0.10 requires refcount_bits=16
 refcount bits: 64
 No errors were found on the image.
 refcount bits: 16
 refcount bits: 16
-qemu-img: Refcount widths other than 16 bits require compatibility level 1.1 or above (use compat=1.1 or greater)
+qemu-img: error: Refcount widths other than 16 bits require compatibility level 1.1 or above (use compat=1.1 or greater)
 refcount bits: 16
 
 === Amend with snapshot ===
 
 wrote 16777216/16777216 bytes at offset 0
 16 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Cannot decrease refcount entry width to 1 bits: Cluster at offset 0x50000 has a refcount of 2
+qemu-img: error: Cannot decrease refcount entry width to 1 bits: Cluster at offset 0x50000 has a refcount of 2
 No errors were found on the image.
 refcount bits: 16
 No errors were found on the image.
diff --git a/tests/qemu-iotests/113.out b/tests/qemu-iotests/113.out
index 3557e2bbf0..4d3386fa49 100644
--- a/tests/qemu-iotests/113.out
+++ b/tests/qemu-iotests/113.out
@@ -2,15 +2,15 @@ QA output created by 113
 
 === Unsupported image creation in qemu-img create ===
 
-qemu-img: nbd://example.com: Format driver 'bochs' does not support image creation
+qemu-img: error: nbd://example.com: Format driver 'bochs' does not support image creation
 
 === Unsupported image creation in qemu-img convert ===
 
-qemu-img: Format driver 'bochs' does not support image creation
+qemu-img: error: Format driver 'bochs' does not support image creation
 
 === Unsupported format in qemu-img amend ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
-qemu-img: Format driver 'IMGFMT' does not support option amendment
+qemu-img: error: Format driver 'IMGFMT' does not support option amendment
 
 *** done
diff --git a/tests/qemu-iotests/114.out b/tests/qemu-iotests/114.out
index 67adef37a4..4960bb52cf 100644
--- a/tests/qemu-iotests/114.out
+++ b/tests/qemu-iotests/114.out
@@ -7,7 +7,7 @@ virtual size: 64 MiB (67108864 bytes)
 cluster_size: 65536
 backing file: TEST_DIR/t.IMGFMT.base
 backing file format: foo
-qemu-io: can't open device TEST_DIR/t.qcow2: Could not open backing file: Unknown driver 'foo'
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Could not open backing file: Unknown driver 'foo'
 no file open, try 'help open'
 read 4096/4096 bytes at offset 0
 4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
diff --git a/tests/qemu-iotests/122.out b/tests/qemu-iotests/122.out
index 849b6cc2ef..ce69c388f4 100644
--- a/tests/qemu-iotests/122.out
+++ b/tests/qemu-iotests/122.out
@@ -79,8 +79,8 @@ read 65536/65536 bytes at offset 4194304
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 read 65536/65536 bytes at offset 8388608
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: Having a backing file for the target makes no sense when concatenating multiple input images
-qemu-img: Having a backing file for the target makes no sense when concatenating multiple input images
+qemu-img: error: Having a backing file for the target makes no sense when concatenating multiple input images
+qemu-img: error: Having a backing file for the target makes no sense when concatenating multiple input images
 
 === Compression with misaligned allocations and image sizes ===
 
diff --git a/tests/qemu-iotests/133.out b/tests/qemu-iotests/133.out
index 1491ef45a9..076ce0e6b1 100644
--- a/tests/qemu-iotests/133.out
+++ b/tests/qemu-iotests/133.out
@@ -4,18 +4,18 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 backing_file=TEST_DIR/t
 
 === Check that node-name can't be changed ===
 
-qemu-io: Cannot change the option 'node-name'
-qemu-io: Cannot change the option 'node-name'
-qemu-io: Cannot change the option 'node-name'
+qemu-io: error: Cannot change the option 'node-name'
+qemu-io: error: Cannot change the option 'node-name'
+qemu-io: error: Cannot change the option 'node-name'
 
 === Check that unchanged node-name is okay ===
 
 
 === Check that driver can't be changed ===
 
-qemu-io: Cannot change the option 'driver'
-qemu-io: Cannot change the option 'driver'
-qemu-io: Cannot change the option 'driver'
+qemu-io: error: Cannot change the option 'driver'
+qemu-io: error: Cannot change the option 'driver'
+qemu-io: error: Cannot change the option 'driver'
 
 === Check that unchanged driver is okay ===
 
@@ -27,16 +27,16 @@ format name: null-co
 
 === Check that mixing -c/-r/-w and their corresponding options is forbidden ===
 
-qemu-io: Cannot set both -r/-w and 'read-only'
-qemu-io: Cannot set both -r/-w and 'read-only'
-qemu-io: Cannot set both -c and the cache options
-qemu-io: Cannot set both -c and the cache options
-qemu-io: Cannot set both -c and the cache options
+qemu-io: error: Cannot set both -r/-w and 'read-only'
+qemu-io: error: Cannot set both -r/-w and 'read-only'
+qemu-io: error: Cannot set both -c and the cache options
+qemu-io: error: Cannot set both -c and the cache options
+qemu-io: error: Cannot set both -c and the cache options
 
 === Check that invalid options are handled correctly ===
 
-qemu-io: Parameter 'read-only' expects 'on' or 'off'
-qemu-io: Parameter 'cache.no-flush' expects 'on' or 'off'
-qemu-io: Parameter 'cache.direct' expects 'on' or 'off'
-qemu-io: Parameter 'auto-read-only' expects 'on' or 'off'
+qemu-io: error: Parameter 'read-only' expects 'on' or 'off'
+qemu-io: error: Parameter 'cache.no-flush' expects 'on' or 'off'
+qemu-io: error: Parameter 'cache.direct' expects 'on' or 'off'
+qemu-io: error: Parameter 'auto-read-only' expects 'on' or 'off'
 *** done
diff --git a/tests/qemu-iotests/137.out b/tests/qemu-iotests/137.out
index 86377c80cd..e88776f57d 100644
--- a/tests/qemu-iotests/137.out
+++ b/tests/qemu-iotests/137.out
@@ -15,30 +15,30 @@ read 33554432/33554432 bytes at offset 0
 
 === Try setting some invalid values ===
 
-qemu-io: Parameter 'lazy-refcounts' expects 'on' or 'off'
-qemu-io: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
-qemu-io: l2-cache-size may not exceed cache-size
-qemu-io: refcount-cache-size may not exceed cache-size
-qemu-io: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
-qemu-io: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
-qemu-io: Refcount cache size too big
-qemu-io: Conflicting values for qcow2 options 'overlap-check' ('constant') and 'overlap-check.template' ('all')
-qemu-io: Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
-qemu-io: Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
-qemu-io: Cache clean interval too big
+qemu-io: error: Parameter 'lazy-refcounts' expects 'on' or 'off'
+qemu-io: error: cache-size, l2-cache-size and refcount-cache-size may not be set at the same time
+qemu-io: error: l2-cache-size may not exceed cache-size
+qemu-io: error: refcount-cache-size may not exceed cache-size
+qemu-io: error: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
+qemu-io: error: L2 cache entry size must be a power of two between 512 and the cluster size (65536)
+qemu-io: error: Refcount cache size too big
+qemu-io: error: Conflicting values for qcow2 options 'overlap-check' ('constant') and 'overlap-check.template' ('all')
+qemu-io: error: Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
+qemu-io: error: Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
+qemu-io: error: Cache clean interval too big
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=36028797018963968
-qemu-io: L2 cache size too big
+qemu-io: error: L2 cache size too big
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 
 === Test transaction semantics ===
 
-qemu-io: Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
+qemu-io: error: Unsupported value 'blubb' for qcow2 option 'overlap-check'. Allowed are any of the following: none, constant, cached, all
 wrote 512/512 bytes at offset 0
 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 ./common.rc: Killed                  ( VALGRIND_QEMU="${VALGRIND_QEMU_IO}" _qemu_proc_exec "${VALGRIND_LOGFILE}" "$QEMU_IO_PROG" $QEMU_IO_ARGS "$@" )
 OK: Dirty bit not set
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: Parameter 'lazy-refcounts' expects 'on' or 'off'
+qemu-io: error: Parameter 'lazy-refcounts' expects 'on' or 'off'
 qcow2: Marking image as corrupt: Preventing invalid allocation of L2 table at offset 0; further corruption events will be suppressed
 write failed: Input/output error
 *** done
diff --git a/tests/qemu-iotests/140.out b/tests/qemu-iotests/140.out
index 86b985da75..24cb816f24 100644
--- a/tests/qemu-iotests/140.out
+++ b/tests/qemu-iotests/140.out
@@ -12,7 +12,7 @@ read 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 { 'execute': 'eject', 'arguments': { 'device': 'drv' }}
 {"return": {}}
-qemu-io: can't open device nbd+unix:///drv?socket=SOCK_DIR/nbd: Requested export not available
+qemu-io: error: can't open device nbd+unix:///drv?socket=SOCK_DIR/nbd: Requested export not available
 server reported: export 'drv' not present
 { 'execute': 'quit' }
 {"return": {}}
diff --git a/tests/qemu-iotests/142.out b/tests/qemu-iotests/142.out
index 3667e38def..a63c49044b 100644
--- a/tests/qemu-iotests/142.out
+++ b/tests/qemu-iotests/142.out
@@ -26,7 +26,7 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) quit
 
 Testing: -drive file=TEST_DIR/t.qcow2,cache=invalid_value
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,cache=invalid_value: invalid cache option
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,cache=invalid_value: error: invalid cache option
 
 
 === Check inheritance of cache modes ===
@@ -71,13 +71,13 @@ cache.writeback=off on none0
     Cache mode:       writeback
 
 cache.writeback=off on file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: error: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: error: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: error: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0
@@ -147,13 +147,13 @@ cache.writeback=off on none0
     Cache mode:       writeback
 
 cache.writeback=off on file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: error: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: error: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: error: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0
@@ -223,13 +223,13 @@ cache.writeback=off on none0
     Cache mode:       writeback, direct
 
 cache.writeback=off on file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: error: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: error: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: error: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0
@@ -299,13 +299,13 @@ cache.writeback=off on none0
     Cache mode:       writeback, direct
 
 cache.writeback=off on file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: error: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: error: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: error: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0
@@ -375,13 +375,13 @@ cache.writeback=off on none0
     Cache mode:       writeback
 
 cache.writeback=off on file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: error: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: error: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: error: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0
@@ -704,13 +704,13 @@ cache.writeback=off on none0
     Cache mode:       writeback, direct
 
 cache.writeback=off on file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,file.cache.writeback=off: error: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 cache.writeback=off on backing
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.cache.writeback=off: error: Could not open backing file: Block format 'qcow2' does not support the option 'cache.writeback'
 
 cache.writeback=off on backing-file
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,backing.file.filename=TEST_DIR/t.qcow2.base,node-name=image,backing.node-name=backing,backing.file.node-name=backing-file,file.node-name=file,backing.file.cache.writeback=off: error: Could not open backing file: Block protocol 'file' doesn't support the option 'cache.writeback'
 
 
 cache.no-flush=on on none0
diff --git a/tests/qemu-iotests/143.out b/tests/qemu-iotests/143.out
index 1f4001c601..8db19060f6 100644
--- a/tests/qemu-iotests/143.out
+++ b/tests/qemu-iotests/143.out
@@ -3,7 +3,7 @@ QA output created by 143
 {"return": {}}
 { 'execute': 'nbd-server-start', 'arguments': { 'addr': { 'type': 'unix', 'data': { 'path': 'SOCK_DIR/nbd' }}}}
 {"return": {}}
-qemu-io: can't open device nbd+unix:///no_such_export?socket=SOCK_DIR/nbd: Requested export not available
+qemu-io: error: can't open device nbd+unix:///no_such_export?socket=SOCK_DIR/nbd: Requested export not available
 server reported: export 'no_such_export' not present
 { 'execute': 'quit' }
 {"return": {}}
diff --git a/tests/qemu-iotests/153.out b/tests/qemu-iotests/153.out
index f7464dd8d3..99e7659899 100644
--- a/tests/qemu-iotests/153.out
+++ b/tests/qemu-iotests/153.out
@@ -1,6 +1,6 @@
 QA output created by 153
 == readonly=off,force-share=on should be rejected ==
-QEMU_PROG: -drive if=none,file=null-co://,readonly=off,force-share=on: force-share=on can only be used with read-only images
+QEMU_PROG: -drive if=none,file=null-co://,readonly=off,force-share=on: error: force-share=on can only be used with read-only images
 
 == Creating base image ==
 Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT size=33554432
@@ -11,11 +11,11 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=33554432 backing_file=TEST_DIR/t
 == Launching QEMU, opts: '' ==
 
 == Launching another QEMU, opts: '' ==
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,: Failed to get "write" lock
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,: error: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Launching another QEMU, opts: 'read-only=on' ==
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,read-only=on: Failed to get shared "write" lock
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,read-only=on: error: Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Launching another QEMU, opts: 'read-only=on,force-share=on' ==
@@ -23,89 +23,89 @@ Is another process using the image [TEST_DIR/t.qcow2]?
 == Running utility commands  ==
 
 _qemu_io_wrapper -c read 0 512 TEST_DIR/t.qcow2
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_io_wrapper -r -c read 0 512 TEST_DIR/t.qcow2
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_io_wrapper -c open  TEST_DIR/t.qcow2 -c read 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 no file open, try 'help open'
 
 _qemu_io_wrapper -c open -r  TEST_DIR/t.qcow2 -c read 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 no file open, try 'help open'
 
 _qemu_img_wrapper info TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper check TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper compare TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper map TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper amend -o  TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper commit TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper resize TEST_DIR/t.qcow2 32M
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper rebase TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper snapshot -l TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper convert TEST_DIR/t.qcow2 TEST_DIR/t.qcow2.convert
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper dd if=TEST_DIR/t.qcow2 of=TEST_DIR/t.qcow2.convert bs=512 count=1
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper bench -c 1 TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper bench -w -c 1 TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper create -f qcow2 TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base
-qemu-img: TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-img: error: TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 file format: IMGFMT
 
 == Running utility commands -U ==
 
 _qemu_io_wrapper -U -c read 0 512 TEST_DIR/t.qcow2
-qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: error: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 
 _qemu_io_wrapper -U -r -c read 0 512 TEST_DIR/t.qcow2
 
 _qemu_io_wrapper -c open -U TEST_DIR/t.qcow2 -c read 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: error: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 no file open, try 'help open'
 
 _qemu_io_wrapper -c open -r -U TEST_DIR/t.qcow2 -c read 0 512
@@ -119,19 +119,19 @@ _qemu_img_wrapper compare -U TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
 _qemu_img_wrapper map -U TEST_DIR/t.qcow2
 
 _qemu_img_wrapper amend -o  -U TEST_DIR/t.qcow2
-qemu-img: unrecognized option '-U'
+qemu-img: error: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
 _qemu_img_wrapper commit -U TEST_DIR/t.qcow2
-qemu-img: unrecognized option '-U'
+qemu-img: error: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
 _qemu_img_wrapper resize -U TEST_DIR/t.qcow2 32M
-qemu-img: unrecognized option '-U'
+qemu-img: error: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
 _qemu_img_wrapper rebase -U TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper snapshot -l -U TEST_DIR/t.qcow2
@@ -143,7 +143,7 @@ _qemu_img_wrapper dd -U if=TEST_DIR/t.qcow2 of=TEST_DIR/t.qcow2.convert bs=512 c
 _qemu_img_wrapper bench -U -c 1 TEST_DIR/t.qcow2
 
 _qemu_img_wrapper bench -U -w -c 1 TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': force-share=on can only be used with read-only images
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': force-share=on can only be used with read-only images
 { 'execute': 'quit' }
 
 Round done
@@ -157,7 +157,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=33554432 backing_file=TEST_DIR/t
 == Launching QEMU, opts: 'read-only=on' ==
 
 == Launching another QEMU, opts: '' ==
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,: Failed to get "write" lock
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,: error: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Launching another QEMU, opts: 'read-only=on' ==
@@ -167,13 +167,13 @@ Is another process using the image [TEST_DIR/t.qcow2]?
 == Running utility commands  ==
 
 _qemu_io_wrapper -c read 0 512 TEST_DIR/t.qcow2
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_io_wrapper -r -c read 0 512 TEST_DIR/t.qcow2
 
 _qemu_io_wrapper -c open  TEST_DIR/t.qcow2 -c read 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 no file open, try 'help open'
 
@@ -188,19 +188,19 @@ _qemu_img_wrapper compare TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
 _qemu_img_wrapper map TEST_DIR/t.qcow2
 
 _qemu_img_wrapper amend -o  TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper commit TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper resize TEST_DIR/t.qcow2 32M
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper rebase TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper snapshot -l TEST_DIR/t.qcow2
@@ -212,23 +212,23 @@ _qemu_img_wrapper dd if=TEST_DIR/t.qcow2 of=TEST_DIR/t.qcow2.convert bs=512 coun
 _qemu_img_wrapper bench -c 1 TEST_DIR/t.qcow2
 
 _qemu_img_wrapper bench -w -c 1 TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper create -f qcow2 TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base
-qemu-img: TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-img: error: TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 file format: IMGFMT
 
 == Running utility commands -U ==
 
 _qemu_io_wrapper -U -c read 0 512 TEST_DIR/t.qcow2
-qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: error: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 
 _qemu_io_wrapper -U -r -c read 0 512 TEST_DIR/t.qcow2
 
 _qemu_io_wrapper -c open -U TEST_DIR/t.qcow2 -c read 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: error: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 no file open, try 'help open'
 
 _qemu_io_wrapper -c open -r -U TEST_DIR/t.qcow2 -c read 0 512
@@ -242,19 +242,19 @@ _qemu_img_wrapper compare -U TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
 _qemu_img_wrapper map -U TEST_DIR/t.qcow2
 
 _qemu_img_wrapper amend -o  -U TEST_DIR/t.qcow2
-qemu-img: unrecognized option '-U'
+qemu-img: error: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
 _qemu_img_wrapper commit -U TEST_DIR/t.qcow2
-qemu-img: unrecognized option '-U'
+qemu-img: error: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
 _qemu_img_wrapper resize -U TEST_DIR/t.qcow2 32M
-qemu-img: unrecognized option '-U'
+qemu-img: error: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
 _qemu_img_wrapper rebase -U TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base
-qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 _qemu_img_wrapper snapshot -l -U TEST_DIR/t.qcow2
@@ -266,7 +266,7 @@ _qemu_img_wrapper dd -U if=TEST_DIR/t.qcow2 of=TEST_DIR/t.qcow2.convert bs=512 c
 _qemu_img_wrapper bench -U -c 1 TEST_DIR/t.qcow2
 
 _qemu_img_wrapper bench -U -w -c 1 TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': force-share=on can only be used with read-only images
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': force-share=on can only be used with read-only images
 { 'execute': 'quit' }
 
 Round done
@@ -327,12 +327,12 @@ file format: IMGFMT
 == Running utility commands -U ==
 
 _qemu_io_wrapper -U -c read 0 512 TEST_DIR/t.qcow2
-qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: error: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 
 _qemu_io_wrapper -U -r -c read 0 512 TEST_DIR/t.qcow2
 
 _qemu_io_wrapper -c open -U TEST_DIR/t.qcow2 -c read 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
+qemu-io: error: can't open device TEST_DIR/t.qcow2: force-share=on can only be used with read-only images
 no file open, try 'help open'
 
 _qemu_io_wrapper -c open -r -U TEST_DIR/t.qcow2 -c read 0 512
@@ -346,15 +346,15 @@ _qemu_img_wrapper compare -U TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
 _qemu_img_wrapper map -U TEST_DIR/t.qcow2
 
 _qemu_img_wrapper amend -o  -U TEST_DIR/t.qcow2
-qemu-img: unrecognized option '-U'
+qemu-img: error: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
 _qemu_img_wrapper commit -U TEST_DIR/t.qcow2
-qemu-img: unrecognized option '-U'
+qemu-img: error: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
 _qemu_img_wrapper resize -U TEST_DIR/t.qcow2 32M
-qemu-img: unrecognized option '-U'
+qemu-img: error: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
 _qemu_img_wrapper rebase -U TEST_DIR/t.qcow2 -b TEST_DIR/t.qcow2.base
@@ -368,23 +368,23 @@ _qemu_img_wrapper dd -U if=TEST_DIR/t.qcow2 of=TEST_DIR/t.qcow2.convert bs=512 c
 _qemu_img_wrapper bench -U -c 1 TEST_DIR/t.qcow2
 
 _qemu_img_wrapper bench -U -w -c 1 TEST_DIR/t.qcow2
-qemu-img: Could not open 'TEST_DIR/t.qcow2': force-share=on can only be used with read-only images
+qemu-img: error: Could not open 'TEST_DIR/t.qcow2': force-share=on can only be used with read-only images
 { 'execute': 'quit' }
 
 Round done
 
 == Two devices with the same image (read-only=off - read-only=off) ==
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=off: Failed to get "write" lock
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=off: error: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Two devices with the same image (read-only=off - read-only=on) ==
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=on: Failed to get shared "write" lock
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=on: error: Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Two devices with the same image (read-only=off - read-only=on,force-share=on) ==
 
 == Two devices with the same image (read-only=on - read-only=off) ==
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=off: Failed to get "write" lock
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2,read-only=off: error: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Two devices with the same image (read-only=on - read-only=on) ==
@@ -405,13 +405,13 @@ Formatting 'TEST_DIR/t.IMGFMT.c', fmt=IMGFMT size=33554432 backing_file=TEST_DIR
 == Two devices sharing the same file in backing chain ==
 
 == Backing image also as an active device ==
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2: Failed to get "write" lock
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2: error: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Backing image also as an active device (ro) ==
 
 == Symbolic link ==
-QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2: Failed to get "write" lock
+QEMU_PROG: -drive if=none,file=TEST_DIR/t.qcow2: error: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 == Active commit to intermediate layer should work when base in use ==
@@ -426,7 +426,7 @@ Adding drive
 {"return": "OKrn"}
 
 _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 Creating overlay with qemu-img when the guest is running should be allowed
 
@@ -447,7 +447,7 @@ _qemu_img_wrapper info TEST_DIR/t.qcow2
 {"return": ""}
 
 _qemu_io_wrapper TEST_DIR/t.qcow2 -c write 0 512
-qemu-io: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 Closing the other
 { 'execute': 'human-monitor-command', 'arguments': { 'command-line': 'drive_del d1' } }
@@ -464,10 +464,10 @@ virtual size: 1 GiB (1073741824 bytes)
 disk size: unavailable
 
 Conflict:
-qemu-img: --force-share/-U conflicts with image options
+qemu-img: error: --force-share/-U conflicts with image options
 
 No conflict:
 
 Conflict:
-qemu-io: -U conflicts with image options
+qemu-io: error: -U conflicts with image options
 *** done
diff --git a/tests/qemu-iotests/162.out b/tests/qemu-iotests/162.out
index 5a00d36d17..dc73df631c 100644
--- a/tests/qemu-iotests/162.out
+++ b/tests/qemu-iotests/162.out
@@ -1,15 +1,15 @@
 QA output created by 162
 
 === NBD ===
-qemu-img: Could not open 'json:{"driver": "nbd", "host": -1}': address resolution failed for -1:10809: Name or service not known
+qemu-img: error: Could not open 'json:{"driver": "nbd", "host": -1}': address resolution failed for -1:10809: Name or service not known
 image: nbd://localhost:PORT
 image: nbd+unix://?socket=42
 
 === SSH ===
-qemu-img: Could not open 'json:{"driver": "ssh", "host": "localhost", "port": "0", "path": "/foo"}': Failed to connect socket: Connection refused
-qemu-img: Could not open 'driver=ssh,host=localhost,port=0,path=/foo': Failed to connect socket: Connection refused
-qemu-img: Could not open 'json:{"driver": "ssh", "host": "localhost", "port": 0.42, "path": "/foo"}': Parameter 'port' expects a number
-qemu-img: Could not open 'driver=ssh,host=localhost,port=0.42,path=/foo': Parameter 'port' expects a number
+qemu-img: error: Could not open 'json:{"driver": "ssh", "host": "localhost", "port": "0", "path": "/foo"}': Failed to connect socket: Connection refused
+qemu-img: error: Could not open 'driver=ssh,host=localhost,port=0,path=/foo': Failed to connect socket: Connection refused
+qemu-img: error: Could not open 'json:{"driver": "ssh", "host": "localhost", "port": 0.42, "path": "/foo"}': Parameter 'port' expects a number
+qemu-img: error: Could not open 'driver=ssh,host=localhost,port=0.42,path=/foo': Parameter 'port' expects a number
 
 === blkdebug ===
 image: blkdebug:42:null-co://
diff --git a/tests/qemu-iotests/172.out b/tests/qemu-iotests/172.out
index 7abbe82427..6d07b96028 100644
--- a/tests/qemu-iotests/172.out
+++ b/tests/qemu-iotests/172.out
@@ -724,10 +724,10 @@ Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device fl
                 drive-type = "144"
 
 Testing: -fda TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device floppy,drive=none0,unit=0
-QEMU_PROG: -device floppy,drive=none0,unit=0: Floppy unit 0 is in use
+QEMU_PROG: -device floppy,drive=none0,unit=0: error: Floppy unit 0 is in use
 
 Testing: -fdb TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device floppy,drive=none0,unit=1
-QEMU_PROG: -device floppy,drive=none0,unit=1: Floppy unit 1 is in use
+QEMU_PROG: -device floppy,drive=none0,unit=1: error: Floppy unit 1 is in use
 
 
 === Mixing -drive and -device ===
@@ -809,7 +809,7 @@ Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.q
                 drive-type = "144"
 
 Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -device floppy,drive=none0,unit=0
-QEMU_PROG: -device floppy,drive=none0,unit=0: Floppy unit 0 is in use
+QEMU_PROG: -device floppy,drive=none0,unit=0: error: Floppy unit 0 is in use
 
 
 === Mixing -global and -device ===
@@ -967,16 +967,16 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qco
                 drive-type = "144"
 
 Testing: -drive if=none,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -global isa-fdc.driveA=none0 -device floppy,drive=none1,unit=0
-QEMU_PROG: -device floppy,drive=none1,unit=0: Floppy unit 0 is in use
+QEMU_PROG: -device floppy,drive=none1,unit=0: error: Floppy unit 0 is in use
 
 Testing: -drive if=none,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -global isa-fdc.driveB=none0 -device floppy,drive=none1,unit=1
-QEMU_PROG: -device floppy,drive=none1,unit=1: Floppy unit 1 is in use
+QEMU_PROG: -device floppy,drive=none1,unit=1: error: Floppy unit 1 is in use
 
 
 === Too many floppy drives ===
 
 Testing: -drive if=floppy,file=TEST_DIR/t.qcow2 -drive if=none,file=TEST_DIR/t.qcow2.2 -drive if=none,file=TEST_DIR/t.qcow2.3 -global isa-fdc.driveB=none0 -device floppy,drive=none1
-QEMU_PROG: -device floppy,drive=none1: Can't create floppy unit 2, bus supports only 2 units
+QEMU_PROG: -device floppy,drive=none1: error: Can't create floppy unit 2, bus supports only 2 units
 
 
 === Creating an empty drive with anonymous BB ===
@@ -1204,10 +1204,10 @@ Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,physica
                 drive-type = "144"
 
 Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,logical_block_size=4096
-QEMU_PROG: -device floppy,drive=none0,logical_block_size=4096: Physical and logical block size must be 512 for floppy
+QEMU_PROG: -device floppy,drive=none0,logical_block_size=4096: error: Physical and logical block size must be 512 for floppy
 
 Testing: -drive if=none,file=TEST_DIR/t.qcow2 -device floppy,drive=none0,physical_block_size=1024
-QEMU_PROG: -device floppy,drive=none0,physical_block_size=1024: Physical and logical block size must be 512 for floppy
+QEMU_PROG: -device floppy,drive=none0,physical_block_size=1024: error: Physical and logical block size must be 512 for floppy
 
 
 === Writethrough caching ===
diff --git a/tests/qemu-iotests/178.out.qcow2 b/tests/qemu-iotests/178.out.qcow2
index 9e7d8c44df..1131c41853 100644
--- a/tests/qemu-iotests/178.out.qcow2
+++ b/tests/qemu-iotests/178.out.qcow2
@@ -2,19 +2,19 @@ QA output created by 178
 == Input validation ==
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
-qemu-img: Either --size N or one filename must be specified.
-qemu-img: --size N cannot be used together with a filename.
-qemu-img: At most one filename argument is allowed.
-qemu-img: --object, --image-opts, -f, and -l require a filename argument.
-qemu-img: --object, --image-opts, -f, and -l require a filename argument.
-qemu-img: --object, --image-opts, -f, and -l require a filename argument.
-qemu-img: --object, --image-opts, -f, and -l require a filename argument.
-qemu-img: Invalid option list: ,
-qemu-img: Invalid parameter 'snapshot.foo'
-qemu-img: Failed in parsing snapshot param 'snapshot.foo'
-qemu-img: --output must be used with human or json as argument.
-qemu-img: Image size must be less than 8 EiB!
-qemu-img: Unknown file format 'foo'
+qemu-img: error: Either --size N or one filename must be specified.
+qemu-img: error: --size N cannot be used together with a filename.
+qemu-img: error: At most one filename argument is allowed.
+qemu-img: error: --object, --image-opts, -f, and -l require a filename argument.
+qemu-img: error: --object, --image-opts, -f, and -l require a filename argument.
+qemu-img: error: --object, --image-opts, -f, and -l require a filename argument.
+qemu-img: error: --object, --image-opts, -f, and -l require a filename argument.
+qemu-img: error: Invalid option list: ,
+qemu-img: error: Invalid parameter 'snapshot.foo'
+qemu-img: error: Failed in parsing snapshot param 'snapshot.foo'
+qemu-img: error: --output must be used with human or json as argument.
+qemu-img: error: Image size must be less than 8 EiB!
+qemu-img: error: Unknown file format 'foo'
 
 == Size calculation for a new file (human) ==
 
@@ -30,7 +30,7 @@ required size: 168034304
 fully allocated size: 1099679662080
 required size: 343650009088
 fully allocated size: 2252143463694336
-qemu-img: The image size is too large (try using a larger cluster size)
+qemu-img: error: The image size is too large (try using a larger cluster size)
 
 == Empty qcow2 input image (human) ==
 
@@ -167,7 +167,7 @@ converted image file size in bytes: 8716288
     "required": 343650009088,
     "fully-allocated": 2252143463694336
 }
-qemu-img: The image size is too large (try using a larger cluster size)
+qemu-img: error: The image size is too large (try using a larger cluster size)
 
 == Empty qcow2 input image (json) ==
 
diff --git a/tests/qemu-iotests/178.out.raw b/tests/qemu-iotests/178.out.raw
index 6478365905..bfda347e59 100644
--- a/tests/qemu-iotests/178.out.raw
+++ b/tests/qemu-iotests/178.out.raw
@@ -2,19 +2,19 @@ QA output created by 178
 == Input validation ==
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824
-qemu-img: Either --size N or one filename must be specified.
-qemu-img: --size N cannot be used together with a filename.
-qemu-img: At most one filename argument is allowed.
-qemu-img: --object, --image-opts, -f, and -l require a filename argument.
-qemu-img: --object, --image-opts, -f, and -l require a filename argument.
-qemu-img: --object, --image-opts, -f, and -l require a filename argument.
-qemu-img: --object, --image-opts, -f, and -l require a filename argument.
-qemu-img: Invalid option list: ,
-qemu-img: Invalid parameter 'snapshot.foo'
-qemu-img: Failed in parsing snapshot param 'snapshot.foo'
-qemu-img: --output must be used with human or json as argument.
-qemu-img: Image size must be less than 8 EiB!
-qemu-img: Unknown file format 'foo'
+qemu-img: error: Either --size N or one filename must be specified.
+qemu-img: error: --size N cannot be used together with a filename.
+qemu-img: error: At most one filename argument is allowed.
+qemu-img: error: --object, --image-opts, -f, and -l require a filename argument.
+qemu-img: error: --object, --image-opts, -f, and -l require a filename argument.
+qemu-img: error: --object, --image-opts, -f, and -l require a filename argument.
+qemu-img: error: --object, --image-opts, -f, and -l require a filename argument.
+qemu-img: error: Invalid option list: ,
+qemu-img: error: Invalid parameter 'snapshot.foo'
+qemu-img: error: Failed in parsing snapshot param 'snapshot.foo'
+qemu-img: error: --output must be used with human or json as argument.
+qemu-img: error: Image size must be less than 8 EiB!
+qemu-img: error: Unknown file format 'foo'
 
 == Size calculation for a new file (human) ==
 
diff --git a/tests/qemu-iotests/182.out b/tests/qemu-iotests/182.out
index a8eea166c3..0b3d4b524f 100644
--- a/tests/qemu-iotests/182.out
+++ b/tests/qemu-iotests/182.out
@@ -3,7 +3,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=33554432
 Starting QEMU
 
 Starting a second QEMU using the same image should fail
-QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,id=drive0,file.locking=on: Failed to get "write" lock
+QEMU_PROG: -drive file=TEST_DIR/t.qcow2,if=none,id=drive0,file.locking=on: error: Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
 === Testing reopen ===
diff --git a/tests/qemu-iotests/187.out b/tests/qemu-iotests/187.out
index 86203d8abc..17beda25d0 100644
--- a/tests/qemu-iotests/187.out
+++ b/tests/qemu-iotests/187.out
@@ -3,16 +3,16 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
 
 Start from read-only
 
-qemu-io: Block node is read-only
+qemu-io: error: Block node is read-only
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-io: Block node is read-only
+qemu-io: error: Block node is read-only
 
 Start from read-write
 
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-io: Block node is read-only
+qemu-io: error: Block node is read-only
 wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 *** done
diff --git a/tests/qemu-iotests/188.out b/tests/qemu-iotests/188.out
index c568ef3701..44cff331f0 100644
--- a/tests/qemu-iotests/188.out
+++ b/tests/qemu-iotests/188.out
@@ -14,7 +14,7 @@ read 16777216/16777216 bytes at offset 0
 16 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == verify open failure with wrong password ==
-qemu-io: can't open: Invalid password, cannot unlock any keyslot
+qemu-io: error: can't open: Invalid password, cannot unlock any keyslot
 
 == verify that has_zero_init returns false when preallocating ==
 Formatting 'TEST_DIR/t.IMGFMT.orig', fmt=IMGFMT size=16777216
diff --git a/tests/qemu-iotests/197.out b/tests/qemu-iotests/197.out
index 7ca46be6e4..411c14e2db 100644
--- a/tests/qemu-iotests/197.out
+++ b/tests/qemu-iotests/197.out
@@ -16,7 +16,7 @@ read 2147483136/2147483136 bytes at offset 1024
 2 GiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 read 1024/1024 bytes at offset 3221226496
 1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-io: can't open device TEST_DIR/t.wrap.qcow2: Can't use copy-on-read on read-only device
+qemu-io: error: can't open device TEST_DIR/t.wrap.qcow2: Can't use copy-on-read on read-only device
 2 GiB (0x80010000) bytes     allocated at offset 0 bytes (0x0)
 1023.938 MiB (0x3fff0000) bytes not allocated at offset 2 GiB (0x80010000)
 64 KiB (0x10000) bytes     allocated at offset 3 GiB (0xc0000000)
diff --git a/tests/qemu-iotests/205 b/tests/qemu-iotests/205
index 4bb2c21e8b..9e80fc7d15 100755
--- a/tests/qemu-iotests/205
+++ b/tests/qemu-iotests/205
@@ -78,7 +78,7 @@ class TestNbdServerRemove(iotests.QMPTestCase):
 
     def assertConnectFailed(self, qemu_io_output):
         self.assertEqual(filter_qemu_io(qemu_io_output).strip(),
-                         "qemu-io: can't open device " + nbd_uri +
+                         "qemu-io: error: can't open device " + nbd_uri +
                          ": Requested export not available\n"
                          "server reported: export 'exp' not present")
 
diff --git a/tests/qemu-iotests/215.out b/tests/qemu-iotests/215.out
index 5a2fe40d03..9917f48205 100644
--- a/tests/qemu-iotests/215.out
+++ b/tests/qemu-iotests/215.out
@@ -16,7 +16,7 @@ read 2147483136/2147483136 bytes at offset 1024
 2 GiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 read 1024/1024 bytes at offset 3221226496
 1 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-io: can't open device TEST_DIR/t.wrap.qcow2: Block node is read-only
+qemu-io: error: can't open device TEST_DIR/t.wrap.qcow2: Block node is read-only
 2 GiB (0x80010000) bytes     allocated at offset 0 bytes (0x0)
 1023.938 MiB (0x3fff0000) bytes not allocated at offset 2 GiB (0x80010000)
 64 KiB (0x10000) bytes     allocated at offset 3 GiB (0xc0000000)
diff --git a/tests/qemu-iotests/217.out b/tests/qemu-iotests/217.out
index e3fc40a8c7..702c6d825b 100644
--- a/tests/qemu-iotests/217.out
+++ b/tests/qemu-iotests/217.out
@@ -10,7 +10,7 @@ Snapshot list:
 (Snapshot filtered)
 
 qcow2_free_clusters failed: Input/output error
-qemu-img: Could not delete snapshot 'foo': Failed to free the cluster and L1 table: Input/output error
+qemu-img: error: Could not delete snapshot 'foo': Failed to free the cluster and L1 table: Input/output error
 
 --- Checking test image ---
 Leaked cluster 4 refcount=2 reference=1
diff --git a/tests/qemu-iotests/226.out b/tests/qemu-iotests/226.out
index 42be973ff2..5b06a97430 100644
--- a/tests/qemu-iotests/226.out
+++ b/tests/qemu-iotests/226.out
@@ -3,24 +3,24 @@ QA output created by 226
 === Testing with driver:file ===
 
 == Testing RO ==
-qemu-io: can't open: A regular file was expected by the 'file' driver, but something else was given
+qemu-io: error: can't open: A regular file was expected by the 'file' driver, but something else was given
 qemu-io: warning: Opening a character device as a file using the 'file' driver is deprecated
 == Testing RW ==
-qemu-io: can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
+qemu-io: error: can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
 qemu-io: warning: Opening a character device as a file using the 'file' driver is deprecated
 
 === Testing with driver:host_device ===
 
 == Testing RO ==
-qemu-io: can't open: 'host_device' driver expects either a character or block device
+qemu-io: error: can't open: 'host_device' driver expects either a character or block device
 == Testing RW ==
-qemu-io: can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
+qemu-io: error: can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
 
 === Testing with driver:host_cdrom ===
 
 == Testing RO ==
-qemu-io: can't open: 'host_cdrom' driver expects either a character or block device
+qemu-io: error: can't open: 'host_cdrom' driver expects either a character or block device
 == Testing RW ==
-qemu-io: can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
+qemu-io: error: can't open: Could not open 'TEST_DIR/t.IMGFMT': Is a directory
 
 *** done
diff --git a/tests/qemu-iotests/232.out b/tests/qemu-iotests/232.out
index 3bd1a920af..b338f2239c 100644
--- a/tests/qemu-iotests/232.out
+++ b/tests/qemu-iotests/232.out
@@ -21,11 +21,11 @@ NODE_NAME: TEST_DIR/t.IMGFMT (file, read-only)
 NODE_NAME: TEST_DIR/t.IMGFMT (file, read-only)
 NODE_NAME: TEST_DIR/t.IMGFMT (file, read-only)
 
-QEMU_PROG: -drive driver=file,file=TEST_DIR/t.IMGFMT,if=none,read-only=off,auto-read-only=off: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
+QEMU_PROG: -drive driver=file,file=TEST_DIR/t.IMGFMT,if=none,read-only=off,auto-read-only=off: error: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
 NODE_NAME: TEST_DIR/t.IMGFMT (file)
 NODE_NAME: TEST_DIR/t.IMGFMT (file)
 
-QEMU_PROG: -drive driver=file,file=TEST_DIR/t.IMGFMT,if=none,auto-read-only=off: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
+QEMU_PROG: -drive driver=file,file=TEST_DIR/t.IMGFMT,if=none,auto-read-only=off: error: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
 NODE_NAME: TEST_DIR/t.IMGFMT (file)
 NODE_NAME: TEST_DIR/t.IMGFMT (file)
 
@@ -49,11 +49,11 @@ node0: TEST_DIR/t.IMGFMT (file, read-only)
 node0: TEST_DIR/t.IMGFMT (file, read-only)
 node0: TEST_DIR/t.IMGFMT (file, read-only)
 
-QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0,read-only=off,auto-read-only=off: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
+QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0,read-only=off,auto-read-only=off: error: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
 node0: TEST_DIR/t.IMGFMT (file)
-QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0,read-only=off: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
+QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0,read-only=off: error: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
 
-QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0,auto-read-only=off: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
+QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0,auto-read-only=off: error: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
 node0: TEST_DIR/t.IMGFMT (file)
-QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
+QEMU_PROG: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=node0: error: Could not open 'TEST_DIR/t.IMGFMT': Permission denied
 *** done
diff --git a/tests/qemu-iotests/233.out b/tests/qemu-iotests/233.out
index c3c344811b..df7e588b36 100644
--- a/tests/qemu-iotests/233.out
+++ b/tests/qemu-iotests/233.out
@@ -14,16 +14,16 @@ wrote 1048576/1048576 bytes at offset 1048576
 1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == check TLS client to plain server fails ==
-qemu-img: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': Denied by server for option 5 (starttls)
+qemu-img: error: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': Denied by server for option 5 (starttls)
 server reported: TLS not configured
-qemu-nbd: Denied by server for option 5 (starttls)
+qemu-nbd: error: Denied by server for option 5 (starttls)
 server reported: TLS not configured
 
 == check plain client to TLS server fails ==
-qemu-img: Could not open 'nbd://localhost:PORT': TLS negotiation required before option 7 (go)
+qemu-img: error: Could not open 'nbd://localhost:PORT': TLS negotiation required before option 7 (go)
 Did you forget a valid tls-creds?
 server reported: Option 0x7 not permitted before TLS
-qemu-nbd: TLS negotiation required before option 3 (list)
+qemu-nbd: error: TLS negotiation required before option 3 (list)
 Did you forget a valid tls-creds?
 server reported: Option 0x3 not permitted before TLS
 
@@ -47,8 +47,8 @@ exports available: 1
    base:allocation
 
 == check TLS with different CA fails ==
-qemu-img: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': The certificate hasn't got a known issuer
-qemu-nbd: The certificate hasn't got a known issuer
+qemu-img: error: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': The certificate hasn't got a known issuer
+qemu-nbd: error: The certificate hasn't got a known issuer
 
 == perform I/O over TLS ==
 read 1048576/1048576 bytes at offset 1048576
@@ -59,12 +59,12 @@ read 1048576/1048576 bytes at offset 1048576
 1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 
 == check TLS with authorization ==
-qemu-img: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': Failed to read option reply: Cannot read from TLS channel: Software caused connection abort
-qemu-img: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': Failed to read option reply: Cannot read from TLS channel: Software caused connection abort
+qemu-img: error: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': Failed to read option reply: Cannot read from TLS channel: Software caused connection abort
+qemu-img: error: Could not open 'driver=nbd,host=127.0.0.1,port=PORT,tls-creds=tls0': Failed to read option reply: Cannot read from TLS channel: Software caused connection abort
 
 == final server log ==
-qemu-nbd: option negotiation failed: Verify failed: No certificate was found.
-qemu-nbd: option negotiation failed: Verify failed: No certificate was found.
-qemu-nbd: option negotiation failed: TLS x509 authz check for CN=localhost,O=Cthulhu Dark Lord Enterprises client1,L=R'lyeh,C=South Pacific is denied
-qemu-nbd: option negotiation failed: TLS x509 authz check for CN=localhost,O=Cthulhu Dark Lord Enterprises client3,L=R'lyeh,C=South Pacific is denied
+qemu-nbd: error: option negotiation failed: Verify failed: No certificate was found.
+qemu-nbd: error: option negotiation failed: Verify failed: No certificate was found.
+qemu-nbd: error: option negotiation failed: TLS x509 authz check for CN=localhost,O=Cthulhu Dark Lord Enterprises client1,L=R'lyeh,C=South Pacific is denied
+qemu-nbd: error: option negotiation failed: TLS x509 authz check for CN=localhost,O=Cthulhu Dark Lord Enterprises client3,L=R'lyeh,C=South Pacific is denied
 *** done
diff --git a/tests/qemu-iotests/242.out b/tests/qemu-iotests/242.out
index 7ac8404d11..fe729faa3e 100644
--- a/tests/qemu-iotests/242.out
+++ b/tests/qemu-iotests/242.out
@@ -143,7 +143,7 @@ Test 5
 {"execute": "block-dirty-bitmap-add", "arguments": {"disabled": false, "granularity": 16384, "name": "bitmap-0", "node": "drive0", "persistent": true}}
 {"return": {}}
 Write an unknown bitmap flag '0x4' into a new QCOW2 image at offset 327695
-qemu-img: Could not open 'TEST_IMG': Bitmap 'bitmap-0' doesn't satisfy the constraints
+qemu-img: error: Could not open 'TEST_IMG': Bitmap 'bitmap-0' doesn't satisfy the constraints
 
 Unset the unknown bitmap flag '0x4' in the bitmap directory entry:
 
diff --git a/tests/qemu-iotests/244.out b/tests/qemu-iotests/244.out
index 6a3d0067cc..6e8b9a9a2b 100644
--- a/tests/qemu-iotests/244.out
+++ b/tests/qemu-iotests/244.out
@@ -9,22 +9,22 @@ read 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 read 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-io: can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
 no file open, try 'help open'
 
 Data file required, but without data file name in the image:
-qemu-io: can't open device TEST_DIR/t.qcow2: 'data-file' is required for this image
+qemu-io: error: can't open device TEST_DIR/t.qcow2: 'data-file' is required for this image
 no file open, try 'help open'
 read 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-io: can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
 no file open, try 'help open'
 
 Setting data-file for an image with internal data:
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-io: can't open device TEST_DIR/t.qcow2: 'data-file' can only be set for images with an external data file
+qemu-io: error: can't open device TEST_DIR/t.qcow2: 'data-file' can only be set for images with an external data file
 no file open, try 'help open'
-qemu-io: can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
+qemu-io: error: can't open device TEST_DIR/t.qcow2: Could not open 'inexistent': No such file or directory
 no file open, try 'help open'
 
 === Conflicting features ===
@@ -33,7 +33,7 @@ Convert to compressed target with data file:
 Formatting 'TEST_DIR/t.IMGFMT.src', fmt=IMGFMT size=67108864
 wrote 1048576/1048576 bytes at offset 0
 1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-qemu-img: error while writing sector 0: Operation not supported
+qemu-img: error: error while writing sector 0: Operation not supported
 
 Convert uncompressed, then write compressed data manually:
 Images are identical.
@@ -41,7 +41,7 @@ write failed: Operation not supported
 No errors were found on the image.
 
 Take an internal snapshot:
-qemu-img: Could not create snapshot 'test': -95 (Operation not supported)
+qemu-img: error: Could not create snapshot 'test': -95 (Operation not supported)
 No errors were found on the image.
 
 === Standalone image with external data file (efficient) ===
diff --git a/tests/qemu-iotests/249.out b/tests/qemu-iotests/249.out
index 51307ed0f7..4ce35e2f6a 100644
--- a/tests/qemu-iotests/249.out
+++ b/tests/qemu-iotests/249.out
@@ -8,7 +8,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.
 === Send a write command to a drive opened in read-only mode (1)
 
 { 'execute': 'human-monitor-command', 'arguments': {'command-line': 'qemu-io none0 "aio_write 0 2k"'}}
-{"return": "Block node is read-onlyrn"}
+{"return": "error: Block node is read-onlyrn"}
 
 === Run block-commit on base using an invalid filter node name
 
@@ -20,7 +20,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.
 === Send a write command to a drive opened in read-only mode (2)
 
 { 'execute': 'human-monitor-command', 'arguments': {'command-line': 'qemu-io none0 "aio_write 0 2k"'}}
-{"return": "Block node is read-onlyrn"}
+{"return": "error: Block node is read-onlyrn"}
 
 === Run block-commit on base using the default filter node name
 
@@ -37,5 +37,5 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.
 === Send a write command to a drive opened in read-only mode (3)
 
 { 'execute': 'human-monitor-command', 'arguments': {'command-line': 'qemu-io none0 "aio_write 0 2k"'}}
-{"return": "Block node is read-onlyrn"}
+{"return": "error: Block node is read-onlyrn"}
 *** done
diff --git a/tests/qemu-iotests/261.out b/tests/qemu-iotests/261.out
index 2600354566..176fee892e 100644
--- a/tests/qemu-iotests/261.out
+++ b/tests/qemu-iotests/261.out
@@ -162,12 +162,12 @@ Snapshots in TEST_DIR/t.IMGFMT:
 
 === Reject too much unknown extra data ===
 
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Too much extra metadata in snapshot table entry 3
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Too much extra metadata in snapshot table entry 3
 You can force-remove this extra metadata with qemu-img check -r all
 
-qemu-img: ERROR failed to read the snapshot table: Too much extra metadata in snapshot table entry 3
+qemu-img: error: ERROR failed to read the snapshot table: Too much extra metadata in snapshot table entry 3
 You can force-remove this extra metadata with qemu-img check -r all
-qemu-img: Check failed: File too large
+qemu-img: error: Check failed: File too large
 
 Discarding too much extra metadata in snapshot table entry 3 (65536 > 1024)
 ERROR cluster 10 refcount=0 reference=1
@@ -185,12 +185,12 @@ No errors were found on the image.
 === Snapshot table too big ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Snapshot table is too big
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Snapshot table is too big
 You can force-remove all 1 overhanging snapshots with qemu-img check -r all
 
-qemu-img: ERROR failed to read the snapshot table: Snapshot table is too big
+qemu-img: error: ERROR failed to read the snapshot table: Snapshot table is too big
 You can force-remove all 1 overhanging snapshots with qemu-img check -r all
-qemu-img: Check failed: File too large
+qemu-img: error: Check failed: File too large
 
 Discarding 1 overhanging snapshots (snapshot table is too big)
 Leaked cluster 14 refcount=1 reference=0
@@ -217,12 +217,12 @@ No errors were found on the image.
 
 Snapshot table size should equal 67108872: 67108872
 
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Too much extra metadata in snapshot table entry 505
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Too much extra metadata in snapshot table entry 505
 You can force-remove this extra metadata with qemu-img check -r all
 
-qemu-img: ERROR failed to read the snapshot table: Too much extra metadata in snapshot table entry 505
+qemu-img: error: ERROR failed to read the snapshot table: Too much extra metadata in snapshot table entry 505
 You can force-remove this extra metadata with qemu-img check -r all
-qemu-img: Check failed: File too large
+qemu-img: error: Check failed: File too large
 
 Discarding too much extra metadata in snapshot table entry 505 (116944 > 1024)
 Discarding 1 overhanging snapshots (snapshot table is too big)
@@ -241,11 +241,11 @@ No errors were found on the image.
 === Too many snapshots ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
-qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Snapshot table too large
+qemu-img: error: Could not open 'TEST_DIR/t.IMGFMT': Snapshot table too large
 
-qemu-img: ERROR snapshot table too large
+qemu-img: error: ERROR snapshot table too large
 You can force-remove all 65536 overhanging snapshots with qemu-img check -r all
-qemu-img: Check failed: File too large
+qemu-img: error: Check failed: File too large
 
 Discarding 65536 overhanging snapshots
 Leaked cluster 14 refcount=1 reference=0
diff --git a/tests/qemu-iotests/267.out b/tests/qemu-iotests/267.out
index 8dddb4baa4..7e3f77c259 100644
--- a/tests/qemu-iotests/267.out
+++ b/tests/qemu-iotests/267.out
@@ -6,11 +6,11 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 Testing:
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
-Error: No block device can accept snapshots
+error: No block device can accept snapshots
 (qemu) info snapshots
 No available block device supports snapshots
 (qemu) loadvm snap0
-Error: No block device supports snapshots
+error: No block device supports snapshots
 (qemu) quit
 
 
@@ -20,11 +20,11 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 Testing: -drive driver=file,file=TEST_DIR/t.IMGFMT,if=none
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
-Error: Device 'none0' is writable but does not support snapshots
+error: Device 'none0' is writable but does not support snapshots
 (qemu) info snapshots
 No available block device supports snapshots
 (qemu) loadvm snap0
-Error: Device 'none0' is writable but does not support snapshots
+error: Device 'none0' is writable but does not support snapshots
 (qemu) quit
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
@@ -56,11 +56,11 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 Testing: -drive driver=file,file=TEST_DIR/t.IMGFMT,if=virtio
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
-Error: Device 'virtio0' is writable but does not support snapshots
+error: Device 'virtio0' is writable but does not support snapshots
 (qemu) info snapshots
 No available block device supports snapshots
 (qemu) loadvm snap0
-Error: Device 'virtio0' is writable but does not support snapshots
+error: Device 'virtio0' is writable but does not support snapshots
 (qemu) quit
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
@@ -81,11 +81,11 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
 Testing: -blockdev driver=file,filename=TEST_DIR/t.IMGFMT,node-name=file
 QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) savevm snap0
-Error: Device '' is writable but does not support snapshots
+error: Device '' is writable but does not support snapshots
 (qemu) info snapshots
 No available block device supports snapshots
 (qemu) loadvm snap0
-Error: Device '' is writable but does not support snapshots
+error: Device '' is writable but does not support snapshots
 (qemu) quit
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=134217728
diff --git a/tests/qemu-iotests/common.filter b/tests/qemu-iotests/common.filter
index 3f8ee3e5f7..0f19eeeeca 100644
--- a/tests/qemu-iotests/common.filter
+++ b/tests/qemu-iotests/common.filter
@@ -58,7 +58,7 @@ _filter_imgfmt()
 _filter_qemu_img_check()
 {
     $SED -e '/allocated.*fragmented.*compressed clusters/d' \
-        -e 's/qemu-img: This image format does not support checks/No errors were found on the image./' \
+        -e 's/qemu-img: error: This image format does not support checks/No errors were found on the image./' \
         -e '/Image end offset: [0-9]\+/d'
 }
 
diff --git a/util/qemu-error.c b/util/qemu-error.c
index dac7c7dc50..03ab07341c 100644
--- a/util/qemu-error.c
+++ b/util/qemu-error.c
@@ -217,6 +217,7 @@ static void vreport(report_type type, const char *fmt, va_list ap)
 
     switch (type) {
     case REPORT_TYPE_ERROR:
+        error_printf("error: ");
         break;
     case REPORT_TYPE_WARNING:
         error_printf("warning: ");
