[v5,10/12] stubs: add qemu_ram_block_from_host() and qemu_ram_get_fd()

Commit Message

Stefan Hajnoczi Sept. 27, 2022, 7:34 p.m. UTC

The blkio block driver will need to look up the file descriptor for a
given pointer. This is possible in softmmu builds where the RAMBlock API
is available for querying guest RAM.

Add stubs so tools like qemu-img that link the block layer still build
successfully. In this case there is no guest RAM but that is fine.
Bounce buffers and their file descriptors will be allocated with
libblkio's blkio_alloc_mem_region() so we won't rely on QEMU's
qemu_ram_get_fd() in that case.

Signed-off-by: Stefan Hajnoczi <[e-mail]>
---
 stubs/physmem.c   | 13 +++++++++++++
 stubs/meson.build |  1 +
 2 files changed, 14 insertions(+)
 create mode 100644 stubs/physmem.c

Patch

diff --git a/stubs/physmem.c b/stubs/physmem.c
new file mode 100644
index 0000000000..1fc5f2df29
--- /dev/null
+++ b/stubs/physmem.c
@@ -0,0 +1,13 @@ 
+#include "qemu/osdep.h"
+#include "exec/cpu-common.h"
+
+RAMBlock *qemu_ram_block_from_host(void *ptr, bool round_offset,
+                                   ram_addr_t *offset)
+{
+    return NULL;
+}
+
+int qemu_ram_get_fd(RAMBlock *rb)
+{
+    return -1;
+}
diff --git a/stubs/meson.build b/stubs/meson.build
index d8f3fd5c44..4314161f5f 100644
--- a/stubs/meson.build
+++ b/stubs/meson.build
@@ -29,6 +29,7 @@  stub_ss.add(files('migr-blocker.c'))
 stub_ss.add(files('module-opts.c'))
 stub_ss.add(files('monitor.c'))
 stub_ss.add(files('monitor-core.c'))
+stub_ss.add(files('physmem.c'))
 stub_ss.add(files('qemu-timer-notify-cb.c'))
 stub_ss.add(files('qmp_memory_device.c'))
 stub_ss.add(files('qmp-command-available.c'))