diff --git a/include/block/block_int.h b/include/block/block_int.h
index 0245620bf6..735935841e 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -302,7 +302,7 @@ struct BlockDriver {
     int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs,
         int64_t offset, int64_t bytes, BdrvRequestFlags flags);
     int coroutine_fn (*bdrv_co_pdiscard)(BlockDriverState *bs,
-        int64_t offset, int bytes);
+        int64_t offset, int64_t bytes);
 
     /* Map [offset, offset + nbytes) range onto a child of @bs to copy from,
      * and invoke bdrv_co_copy_range_from(child, ...), or invoke
diff --git a/block/backup-top.c b/block/backup-top.c
index 838027981b..c5ce84def4 100644
--- a/block/backup-top.c
+++ b/block/backup-top.c
@@ -75,7 +75,7 @@ static coroutine_fn int backup_top_cbw(BlockDriverState *bs, uint64_t offset,
 }
 
 static int coroutine_fn backup_top_co_pdiscard(BlockDriverState *bs,
-                                               int64_t offset, int bytes)
+                                               int64_t offset, int64_t bytes)
 {
     int ret = backup_top_cbw(bs, offset, bytes, 0);
     if (ret < 0) {
diff --git a/block/blkdebug.c b/block/blkdebug.c
index c81cb9cb1a..2d98a33982 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -700,7 +700,7 @@ static int coroutine_fn blkdebug_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static int coroutine_fn blkdebug_co_pdiscard(BlockDriverState *bs,
-                                             int64_t offset, int bytes)
+                                             int64_t offset, int64_t bytes)
 {
     uint32_t align = bs->bl.pdiscard_alignment;
     int err;
diff --git a/block/blklogwrites.c b/block/blklogwrites.c
index d7ae64c22d..f7a251e91f 100644
--- a/block/blklogwrites.c
+++ b/block/blklogwrites.c
@@ -484,9 +484,9 @@ static int coroutine_fn blk_log_writes_co_flush_to_disk(BlockDriverState *bs)
 }
 
 static int coroutine_fn
-blk_log_writes_co_pdiscard(BlockDriverState *bs, int64_t offset, int count)
+blk_log_writes_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
 {
-    return blk_log_writes_co_log(bs, offset, count, NULL, 0,
+    return blk_log_writes_co_log(bs, offset, bytes, NULL, 0,
                                  blk_log_writes_co_do_file_pdiscard,
                                  LOG_DISCARD_FLAG, false);
 }
diff --git a/block/blkreplay.c b/block/blkreplay.c
index 89d74a3cca..dcbe780ddb 100644
--- a/block/blkreplay.c
+++ b/block/blkreplay.c
@@ -105,7 +105,7 @@ static int coroutine_fn blkreplay_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static int coroutine_fn blkreplay_co_pdiscard(BlockDriverState *bs,
-                                              int64_t offset, int bytes)
+                                              int64_t offset, int64_t bytes)
 {
     uint64_t reqid = blkreplay_next_id();
     int ret = bdrv_co_pdiscard(bs->file, offset, bytes);
diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index 758a5d44d5..c29cfdd10e 100644
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -214,7 +214,7 @@ static int coroutine_fn cor_co_pwrite_zeroes(BlockDriverState *bs,
 
 
 static int coroutine_fn cor_co_pdiscard(BlockDriverState *bs,
-                                        int64_t offset, int bytes)
+                                        int64_t offset, int64_t bytes)
 {
     return bdrv_co_pdiscard(bs->file, offset, bytes);
 }
diff --git a/block/file-posix.c b/block/file-posix.c
index 03618cc18b..1ea2d0c889 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2899,7 +2899,8 @@ static void raw_account_discard(BDRVRawState *s, uint64_t nbytes, int ret)
 }
 
 static coroutine_fn int
-raw_do_pdiscard(BlockDriverState *bs, int64_t offset, int bytes, bool blkdev)
+raw_do_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes,
+                bool blkdev)
 {
     BDRVRawState *s = bs->opaque;
     RawPosixAIOData acb;
@@ -2923,7 +2924,7 @@ raw_do_pdiscard(BlockDriverState *bs, int64_t offset, int bytes, bool blkdev)
 }
 
 static coroutine_fn int
-raw_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
+raw_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
 {
     return raw_do_pdiscard(bs, offset, bytes, false);
 }
@@ -3563,7 +3564,7 @@ static int fd_open(BlockDriverState *bs)
 }
 
 static coroutine_fn int
-hdev_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
+hdev_co_pdiscard(BlockDriverState *bs, int64_t offset, int64_t bytes)
 {
     BDRVRawState *s = bs->opaque;
     int ret;
diff --git a/block/filter-compress.c b/block/filter-compress.c
index fb85686b69..d5be538619 100644
--- a/block/filter-compress.c
+++ b/block/filter-compress.c
@@ -94,7 +94,7 @@ static int coroutine_fn compress_co_pwrite_zeroes(BlockDriverState *bs,
 
 
 static int coroutine_fn compress_co_pdiscard(BlockDriverState *bs,
-                                             int64_t offset, int bytes)
+                                             int64_t offset, int64_t bytes)
 {
     return bdrv_co_pdiscard(bs->file, offset, bytes);
 }
diff --git a/block/gluster.c b/block/gluster.c
index 6a17b37c0c..066fdf60fa 100644
--- a/block/gluster.c
+++ b/block/gluster.c
@@ -891,6 +891,7 @@ out:
 static void qemu_gluster_refresh_limits(BlockDriverState *bs, Error **errp)
 {
     bs->bl.max_transfer = GLUSTER_MAX_TRANSFER;
+    bs->bl.max_pdiscard = SIZE_MAX;
 }
 
 static int qemu_gluster_reopen_prepare(BDRVReopenState *state,
@@ -1297,18 +1298,20 @@ error:
 
 #ifdef CONFIG_GLUSTERFS_DISCARD
 static coroutine_fn int qemu_gluster_co_pdiscard(BlockDriverState *bs,
-                                                 int64_t offset, int size)
+                                                 int64_t offset, int64_t bytes)
 {
     int ret;
     GlusterAIOCB acb;
     BDRVGlusterState *s = bs->opaque;
 
+    assert(bytes <= SIZE_MAX); /* rely on max_pdiscard */
+
     acb.size = 0;
     acb.ret = 0;
     acb.coroutine = qemu_coroutine_self();
     acb.aio_context = bdrv_get_aio_context(bs);
 
-    ret = glfs_discard_async(s->fd, offset, size, gluster_finish_aiocb, &acb);
+    ret = glfs_discard_async(s->fd, offset, bytes, gluster_finish_aiocb, &acb);
     if (ret < 0) {
         return -errno;
     }
diff --git a/block/iscsi.c b/block/iscsi.c
index b90ed67377..297919ebc2 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -1141,7 +1141,8 @@ iscsi_getlength(BlockDriverState *bs)
 }
 
 static int
-coroutine_fn iscsi_co_pdiscard(BlockDriverState *bs, int64_t offset, int bytes)
+coroutine_fn iscsi_co_pdiscard(BlockDriverState *bs, int64_t offset,
+                               int64_t bytes)
 {
     IscsiLun *iscsilun = bs->opaque;
     struct IscsiTask iTask;
@@ -2075,10 +2076,9 @@ static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp)
     }
 
     if (iscsilun->lbp.lbpu) {
-        if (iscsilun->bl.max_unmap < 0xffffffff / block_size) {
-            bs->bl.max_pdiscard =
-                iscsilun->bl.max_unmap * iscsilun->block_size;
-        }
+        bs->bl.max_pdiscard =
+            MIN_NON_ZERO(iscsilun->bl.max_unmap * iscsilun->block_size,
+                         (uint64_t)UINT32_MAX * iscsilun->block_size);
         bs->bl.pdiscard_alignment =
             iscsilun->bl.opt_unmap_gran * iscsilun->block_size;
     } else {
diff --git a/block/mirror.c b/block/mirror.c
index e40608b2d3..e2038a06d3 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1487,7 +1487,7 @@ static int coroutine_fn bdrv_mirror_top_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static int coroutine_fn bdrv_mirror_top_pdiscard(BlockDriverState *bs,
-    int64_t offset, int bytes)
+    int64_t offset, int64_t bytes)
 {
     return bdrv_mirror_top_do_write(bs, MIRROR_METHOD_DISCARD, offset, bytes,
                                     NULL, 0);
diff --git a/block/nbd.c b/block/nbd.c
index 9ec822c083..cc522a765c 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -1669,15 +1669,17 @@ static int nbd_client_co_flush(BlockDriverState *bs)
 }
 
 static int nbd_client_co_pdiscard(BlockDriverState *bs, int64_t offset,
-                                  int bytes)
+                                  int64_t bytes)
 {
     BDRVNBDState *s = (BDRVNBDState *)bs->opaque;
     NBDRequest request = {
         .type = NBD_CMD_TRIM,
         .from = offset,
-        .len = bytes,
+        .len = bytes, /* len is uint32_t */
     };
 
+    assert(bytes <= UINT32_MAX); /* rely on max_pdiscard */
+
     assert(!(s->info.flags & NBD_FLAG_READ_ONLY));
     if (!(s->info.flags & NBD_FLAG_SEND_TRIM) || !bytes) {
         return 0;
diff --git a/block/nvme.c b/block/nvme.c
index 1263022e1c..0c6c4031f3 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -1329,7 +1329,7 @@ static coroutine_fn int nvme_co_pwrite_zeroes(BlockDriverState *bs,
 
 static int coroutine_fn nvme_co_pdiscard(BlockDriverState *bs,
                                          int64_t offset,
-                                         int bytes)
+                                         int64_t bytes)
 {
     BDRVNVMeState *s = bs->opaque;
     NVMeQueuePair *ioq = s->queues[INDEX_IO(0)];
@@ -1356,6 +1356,14 @@ static int coroutine_fn nvme_co_pdiscard(BlockDriverState *bs,
 
     assert(s->queue_count > 1);
 
+    /*
+     * Filling the @buf requires @offset and @bytes to satisfy restrictions
+     * defined in nvme_refresh_limits().
+     */
+    assert(QEMU_IS_ALIGNED(bytes, 1UL << s->blkshift));
+    assert(QEMU_IS_ALIGNED(offset, 1UL << s->blkshift));
+    assert((bytes >> s->blkshift) <= UINT32_MAX);
+
     buf = qemu_try_memalign(s->page_size, s->page_size);
     if (!buf) {
         return -ENOMEM;
@@ -1459,6 +1467,10 @@ static void nvme_refresh_limits(BlockDriverState *bs, Error **errp)
     bs->bl.max_pwrite_zeroes = 1ULL << (s->blkshift + 16);
     bs->bl.pwrite_zeroes_alignment = MAX(bs->bl.request_alignment,
                                          1UL << s->blkshift);
+
+    bs->bl.max_pdiscard = (uint64_t)UINT32_MAX << s->blkshift;
+    bs->bl.pdiscard_alignment = MAX(bs->bl.request_alignment,
+                                    1UL << s->blkshift);
 }
 
 static void nvme_detach_aio_context(BlockDriverState *bs)
diff --git a/block/preallocate.c b/block/preallocate.c
index 99e28d9f08..1d4233f730 100644
--- a/block/preallocate.c
+++ b/block/preallocate.c
@@ -235,7 +235,7 @@ static coroutine_fn int preallocate_co_preadv_part(
 }
 
 static int coroutine_fn preallocate_co_pdiscard(BlockDriverState *bs,
-                                               int64_t offset, int bytes)
+                                               int64_t offset, int64_t bytes)
 {
     return bdrv_co_pdiscard(bs->file, offset, bytes);
 }
diff --git a/block/qcow2.c b/block/qcow2.c
index c9bce9711d..955e488046 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -3945,7 +3945,7 @@ static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static coroutine_fn int qcow2_co_pdiscard(BlockDriverState *bs,
-                                          int64_t offset, int bytes)
+                                          int64_t offset, int64_t bytes)
 {
     int ret;
     BDRVQcow2State *s = bs->opaque;
diff --git a/block/raw-format.c b/block/raw-format.c
index 4e9304c63b..45846e42d5 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -302,7 +302,7 @@ static int coroutine_fn raw_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static int coroutine_fn raw_co_pdiscard(BlockDriverState *bs,
-                                        int64_t offset, int bytes)
+                                        int64_t offset, int64_t bytes)
 {
     int ret;
 
diff --git a/block/sheepdog.c b/block/sheepdog.c
index a45c73826d..80e04dccfd 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -3101,7 +3101,7 @@ static int sd_load_vmstate(BlockDriverState *bs, QEMUIOVector *qiov,
 
 
 static coroutine_fn int sd_co_pdiscard(BlockDriverState *bs, int64_t offset,
-                                      int bytes)
+                                       int64_t bytes)
 {
     SheepdogAIOCB acb;
     BDRVSheepdogState *s = bs->opaque;
@@ -3113,6 +3113,8 @@ static coroutine_fn int sd_co_pdiscard(BlockDriverState *bs, int64_t offset,
         return 0;
     }
 
+    assert(bytes <= INT_MAX); /* thanks to max_pdiscard */
+
     memset(&discard_iov, 0, sizeof(discard_iov));
     memset(&iov, 0, sizeof(iov));
     iov.iov_base = &zero;
@@ -3186,6 +3188,11 @@ static int64_t sd_get_allocated_file_size(BlockDriverState *bs)
     return size;
 }
 
+static void sd_refresh_limits(BlockDriverState *bs, Error **errp)
+{
+    bs->bl.max_pdiscard = INT_MAX;
+}
+
 static QemuOptsList sd_create_opts = {
     .name = "sheepdog-create-opts",
     .head = QTAILQ_HEAD_INITIALIZER(sd_create_opts.head),
@@ -3269,6 +3276,8 @@ static BlockDriver bdrv_sheepdog = {
 
     .create_opts                  = &sd_create_opts,
     .strong_runtime_opts          = sd_strong_runtime_opts,
+
+    .bdrv_refresh_limits          = sd_refresh_limits,
 };
 
 static BlockDriver bdrv_sheepdog_tcp = {
@@ -3307,6 +3316,8 @@ static BlockDriver bdrv_sheepdog_tcp = {
 
     .create_opts                  = &sd_create_opts,
     .strong_runtime_opts          = sd_strong_runtime_opts,
+
+    .bdrv_refresh_limits          = sd_refresh_limits,
 };
 
 static BlockDriver bdrv_sheepdog_unix = {
@@ -3345,6 +3356,8 @@ static BlockDriver bdrv_sheepdog_unix = {
 
     .create_opts                  = &sd_create_opts,
     .strong_runtime_opts          = sd_strong_runtime_opts,
+
+    .bdrv_refresh_limits          = sd_refresh_limits,
 };
 
 static void bdrv_sheepdog_init(void)
diff --git a/block/throttle.c b/block/throttle.c
index c13fe9067f..6e8d52fa24 100644
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -145,7 +145,7 @@ static int coroutine_fn throttle_co_pwrite_zeroes(BlockDriverState *bs,
 }
 
 static int coroutine_fn throttle_co_pdiscard(BlockDriverState *bs,
-                                             int64_t offset, int bytes)
+                                             int64_t offset, int64_t bytes)
 {
     ThrottleGroupMember *tgm = bs->opaque;
     throttle_group_co_io_limits_intercept(tgm, bytes, true);
diff --git a/tests/unit/test-block-iothread.c b/tests/unit/test-block-iothread.c
index 50b8718b2a..9656814814 100644
--- a/tests/unit/test-block-iothread.c
+++ b/tests/unit/test-block-iothread.c
@@ -48,7 +48,7 @@ static int coroutine_fn bdrv_test_co_pwritev(BlockDriverState *bs,
 }
 
 static int coroutine_fn bdrv_test_co_pdiscard(BlockDriverState *bs,
-                                              int64_t offset, int bytes)
+                                              int64_t offset, int64_t bytes)
 {
     return 0;
 }
diff --git a/block/trace-events b/block/trace-events
index 3edd2899c2..3b86c03b2f 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -152,8 +152,8 @@ nvme_write_zeroes(void *s, uint64_t offset, uint64_t bytes, int flags) "s %p off
 nvme_qiov_unaligned(const void *qiov, int n, void *base, size_t size, int align) "qiov %p n %d base %p size 0x%zx align 0x%x"
 nvme_prw_buffered(void *s, uint64_t offset, uint64_t bytes, int niov, int is_write) "s %p offset 0x%"PRIx64" bytes %"PRId64" niov %d is_write %d"
 nvme_rw_done(void *s, int is_write, uint64_t offset, uint64_t bytes, int ret) "s %p is_write %d offset 0x%"PRIx64" bytes %"PRId64" ret %d"
-nvme_dsm(void *s, uint64_t offset, uint64_t bytes) "s %p offset 0x%"PRIx64" bytes %"PRId64""
-nvme_dsm_done(void *s, uint64_t offset, uint64_t bytes, int ret) "s %p offset 0x%"PRIx64" bytes %"PRId64" ret %d"
+nvme_dsm(void *s, int64_t offset, int64_t bytes) "s %p offset 0x%"PRIx64" bytes %"PRId64""
+nvme_dsm_done(void *s, int64_t offset, int64_t bytes, int ret) "s %p offset 0x%"PRIx64" bytes %"PRId64" ret %d"
 nvme_dma_map_flush(void *s) "s %p"
 nvme_free_req_queue_wait(void *s, unsigned q_index) "s %p q #%u"
 nvme_create_queue_pair(unsigned q_index, void *q, unsigned size, void *aio_context, int fd) "index %u q %p size %u aioctx %p fd %d"
