diff --git a/block.c b/block.c
index e5f214d135..195beff706 100644
--- a/block.c
+++ b/block.c
@@ -851,7 +851,7 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
     }
 
     bs->open_flags = flags;
-    bs->buffer_alignment = 512;
+    bs->guest_block_size = 512;
     bs->zero_beyond_eof = true;
     open_flags = bdrv_open_flags(bs, flags);
     bs->read_only = !(open_flags & BDRV_O_RDWR);
@@ -1796,7 +1796,7 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest,
     bs_dest->dev_ops            = bs_src->dev_ops;
     bs_dest->dev_opaque         = bs_src->dev_opaque;
     bs_dest->dev                = bs_src->dev;
-    bs_dest->buffer_alignment   = bs_src->buffer_alignment;
+    bs_dest->guest_block_size   = bs_src->guest_block_size;
     bs_dest->copy_on_read       = bs_src->copy_on_read;
 
     bs_dest->enable_write_cache = bs_src->enable_write_cache;
@@ -1953,7 +1953,7 @@ void bdrv_detach_dev(BlockDriverState *bs, void *dev)
     bs->dev = NULL;
     bs->dev_ops = NULL;
     bs->dev_opaque = NULL;
-    bs->buffer_alignment = 512;
+    bs->guest_block_size = 512;
 }
 
 /* TODO change to return DeviceState * when all users are qdevified */
@@ -4806,9 +4806,9 @@ BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
     return NULL;
 }
 
-void bdrv_set_buffer_alignment(BlockDriverState *bs, int align)
+void bdrv_set_guest_block_size(BlockDriverState *bs, int align)
 {
-    bs->buffer_alignment = align;
+    bs->guest_block_size = align;
 }
 
 void *qemu_blockalign(BlockDriverState *bs, size_t size)
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 19d0961a47..8a568e5edb 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -731,7 +731,7 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
     register_savevm(dev, "virtio-blk", virtio_blk_id++, 2,
                     virtio_blk_save, virtio_blk_load, s);
     bdrv_set_dev_ops(s->bs, &virtio_block_ops, s);
-    bdrv_set_buffer_alignment(s->bs, s->conf->logical_block_size);
+    bdrv_set_guest_block_size(s->bs, s->conf->logical_block_size);
 
     bdrv_iostatus_enable(s->bs);
 
diff --git a/hw/ide/core.c b/hw/ide/core.c
index e1f4c33fb8..036cd4a6d1 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -2103,7 +2103,7 @@ int ide_init_drive(IDEState *s, BlockDriverState *bs, IDEDriveKind kind,
     s->smart_selftest_count = 0;
     if (kind == IDE_CD) {
         bdrv_set_dev_ops(bs, &ide_cd_block_ops, s);
-        bdrv_set_buffer_alignment(bs, 2048);
+        bdrv_set_guest_block_size(bs, 2048);
     } else {
         if (!bdrv_is_inserted(s->bs)) {
             error_report("Device needs media, but drive is empty");
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index bce617cb93..649109150b 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -2254,7 +2254,7 @@ static int scsi_initfn(SCSIDevice *dev)
     } else {
         bdrv_set_dev_ops(s->qdev.conf.bs, &scsi_disk_block_ops, s);
     }
-    bdrv_set_buffer_alignment(s->qdev.conf.bs, s->qdev.blocksize);
+    bdrv_set_guest_block_size(s->qdev.conf.bs, s->qdev.blocksize);
 
     bdrv_iostatus_enable(s->qdev.conf.bs);
     add_boot_device_path(s->qdev.conf.bootindex, &dev->qdev, NULL);
diff --git a/hw/scsi/scsi-generic.c b/hw/scsi/scsi-generic.c
index 8f195bec00..f08b64e177 100644
--- a/hw/scsi/scsi-generic.c
+++ b/hw/scsi/scsi-generic.c
@@ -210,7 +210,7 @@ static void scsi_read_complete(void * opaque, int ret)
             s->blocksize = ldl_be_p(&r->buf[8]);
             s->max_lba = ldq_be_p(&r->buf[0]);
         }
-        bdrv_set_buffer_alignment(s->conf.bs, s->blocksize);
+        bdrv_set_guest_block_size(s->conf.bs, s->blocksize);
 
         scsi_req_data(&r->req, len);
         if (!r->req.io_canceled) {
diff --git a/include/block/block.h b/include/block/block.h
index 332ebb94fb..a2f5657321 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -431,7 +431,7 @@ void bdrv_img_create(const char *filename, const char *fmt,
 /* Returns the alignment in bytes that is required so that no bounce buffer
  * is required throughout the stack */
 size_t bdrv_opt_mem_align(BlockDriverState *bs);
-void bdrv_set_buffer_alignment(BlockDriverState *bs, int align);
+void bdrv_set_guest_block_size(BlockDriverState *bs, int align);
 void *qemu_blockalign(BlockDriverState *bs, size_t size);
 bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov);
 
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 74a78a6831..ae609bd4d6 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -325,8 +325,8 @@ struct BlockDriverState {
     /* Whether produces zeros when read beyond eof */
     bool zero_beyond_eof;
 
-    /* the memory alignment required for the buffers handled by this driver */
-    int buffer_alignment;
+    /* the block size for which the guest device expects atomicity */
+    int guest_block_size;
 
     /* do we need to tell the quest if we have a volatile write cache? */
     int enable_write_cache;