diff --git a/block_int.h b/block_int.h
index 50e1a0b77..71b633b78 100644
--- a/block_int.h
+++ b/block_int.h
@@ -209,6 +209,7 @@ struct DriveInfo;
 typedef struct BlockConf {
     struct DriveInfo *dinfo;
     uint16_t physical_block_size;
+    uint16_t logical_block_size;
     uint16_t min_io_size;
     uint32_t opt_io_size;
 } BlockConf;
@@ -226,6 +227,8 @@ static inline unsigned int get_physical_block_exp(BlockConf *conf)
 
 #define DEFINE_BLOCK_PROPERTIES(_state, _conf)                          \
     DEFINE_PROP_DRIVE("drive", _state, _conf.dinfo),                    \
+    DEFINE_PROP_UINT16("logical_block_size", _state,                    \
+                       _conf.logical_block_size, 512),                  \
     DEFINE_PROP_UINT16("physical_block_size", _state,                   \
                        _conf.physical_block_size, 512),                 \
     DEFINE_PROP_UINT16("min_io_size", _state, _conf.min_io_size, 512),  \
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index da56d2bc1..e64fbf11d 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -396,8 +396,10 @@ static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf)
         }
         case 0xb0: /* block device characteristics */
         {
-            unsigned int min_io_size = s->qdev.conf.min_io_size >> 9;
-            unsigned int opt_io_size = s->qdev.conf.opt_io_size >> 9;
+            unsigned int min_io_size =
+                    s->qdev.conf.min_io_size / s->qdev.blocksize;
+            unsigned int opt_io_size =
+                    s->qdev.conf.opt_io_size / s->qdev.blocksize;
 
             /* required VPD size with unmap support */
             outbuf[3] = buflen = 0x3c;
@@ -1036,11 +1038,12 @@ static int scsi_disk_initfn(SCSIDevice *dev)
     }
 
     if (bdrv_get_type_hint(s->bs) == BDRV_TYPE_CDROM) {
-        s->cluster_size = 4;
+        s->qdev.blocksize = 2048;
     } else {
-        s->cluster_size = 1;
+        s->qdev.blocksize = s->qdev.conf.logical_block_size;
     }
-    s->qdev.blocksize = 512 * s->cluster_size;
+    s->cluster_size = s->qdev.blocksize / 512;
+
     s->qdev.type = TYPE_DISK;
     bdrv_get_geometry(s->bs, &nb_sectors);
     nb_sectors /= s->cluster_size;
diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index 8939bb252..991584088 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -27,6 +27,7 @@ typedef struct VirtIOBlock
     void *rq;
     QEMUBH *bh;
     BlockConf *conf;
+    unsigned short sector_mask;
 } VirtIOBlock;
 
 static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev)
@@ -250,6 +251,11 @@ static void virtio_blk_handle_flush(VirtIOBlockReq *req)
 static void virtio_blk_handle_write(BlockRequest *blkreq, int *num_writes,
     VirtIOBlockReq *req, BlockDriverState **old_bs)
 {
+    if (req->out->sector & req->dev->sector_mask) {
+        virtio_blk_rw_complete(req, -EIO);
+        return;
+    }
+
     if (req->dev->bs != *old_bs || *num_writes == 32) {
         if (*old_bs != NULL) {
             do_multiwrite(*old_bs, blkreq, *num_writes);
@@ -272,6 +278,11 @@ static void virtio_blk_handle_read(VirtIOBlockReq *req)
 {
     BlockDriverAIOCB *acb;
 
+    if (req->out->sector & req->dev->sector_mask) {
+        virtio_blk_rw_complete(req, -EIO);
+        return;
+    }
+
     acb = bdrv_aio_readv(req->dev->bs, req->out->sector, &req->qiov,
                          req->qiov.size / 512, virtio_blk_rw_complete, req);
     if (!acb) {
@@ -404,12 +415,13 @@ static void virtio_blk_update_config(VirtIODevice *vdev, uint8_t *config)
     stl_raw(&blkcfg.seg_max, 128 - 2);
     stw_raw(&blkcfg.cylinders, cylinders);
     blkcfg.heads = heads;
-    blkcfg.sectors = secs;
+    blkcfg.sectors = secs & ~s->sector_mask;
+    blkcfg.blk_size = s->conf->logical_block_size;
     blkcfg.size_max = 0;
     blkcfg.physical_block_exp = get_physical_block_exp(s->conf);
     blkcfg.alignment_offset = 0;
-    blkcfg.min_io_size = s->conf->min_io_size / 512;
-    blkcfg.opt_io_size = s->conf->opt_io_size / 512;
+    blkcfg.min_io_size = s->conf->min_io_size / blkcfg.blk_size;
+    blkcfg.opt_io_size = s->conf->opt_io_size / blkcfg.blk_size;
     memcpy(config, &blkcfg, sizeof(struct virtio_blk_config));
 }
 
@@ -420,6 +432,7 @@ static uint32_t virtio_blk_get_features(VirtIODevice *vdev, uint32_t features)
     features |= (1 << VIRTIO_BLK_F_SEG_MAX);
     features |= (1 << VIRTIO_BLK_F_GEOMETRY);
     features |= (1 << VIRTIO_BLK_F_TOPOLOGY);
+    features |= (1 << VIRTIO_BLK_F_BLK_SIZE);
 
     if (bdrv_enable_write_cache(s->bs))
         features |= (1 << VIRTIO_BLK_F_WCACHE);
@@ -479,6 +492,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, BlockConf *conf)
     s->bs = conf->dinfo->bdrv;
     s->conf = conf;
     s->rq = NULL;
+    s->sector_mask = (s->conf->logical_block_size / 512) - 1;
     bdrv_guess_geometry(s->bs, &cylinders, &heads, &secs);
     bdrv_set_geometry_hint(s->bs, cylinders, heads, secs);
 
diff --git a/hw/virtio-blk.h b/hw/virtio-blk.h
index f67537539..7a7ece3d9 100644
--- a/hw/virtio-blk.h
+++ b/hw/virtio-blk.h
@@ -42,7 +42,7 @@ struct virtio_blk_config
     uint16_t cylinders;
     uint8_t heads;
     uint8_t sectors;
-    uint32_t _blk_size;    /* structure pad, currently unused */
+    uint32_t blk_size;
     uint8_t physical_block_exp;
     uint8_t alignment_offset;
     uint16_t min_io_size;