diff --git a/block/iscsi.c b/block/iscsi.c
index 0b96165ec2..fb001b955c 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -167,12 +167,6 @@ iscsi_set_events(IscsiLun *iscsilun)
 
     }
 
-    /* If we just added an event, the callback might be delayed
-     * unless we call qemu_notify_event().
-     */
-    if (ev & ~iscsilun->events) {
-        qemu_notify_event();
-    }
     iscsilun->events = ev;
 }
 
@@ -628,9 +622,17 @@ static BlockDriverAIOCB *iscsi_aio_ioctl(BlockDriverState *bs,
     return &acb->common;
 }
 
+
+static void ioctl_cb(void *opaque, int status)
+{
+    int *p_status = opaque;
+    *p_status = status;
+}
+
 static int iscsi_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
 {
     IscsiLun *iscsilun = bs->opaque;
+    int status;
 
     switch (req) {
     case SG_GET_VERSION_NUM:
@@ -639,6 +641,15 @@ static int iscsi_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
     case SG_GET_SCSI_ID:
         ((struct sg_scsi_id *)buf)->scsi_type = iscsilun->type;
         break;
+    case SG_IO:
+        status = -EINPROGRESS;
+        iscsi_aio_ioctl(bs, req, buf, ioctl_cb, &status);
+
+        while (status == -EINPROGRESS) {
+            qemu_aio_wait();
+        }
+
+        return 0;
     default:
         return -1;
     }
diff --git a/hw/scsi-bus.c b/hw/scsi-bus.c
index 4981a02436..058d3b237f 100644
--- a/hw/scsi-bus.c
+++ b/hw/scsi-bus.c
@@ -801,26 +801,39 @@ static int ata_passthrough_16_xfer_size(SCSIDevice *dev, uint8_t *buf)
     return xfer * unit;
 }
 
-static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
+uint32_t scsi_data_cdb_length(uint8_t *buf)
+{
+    if ((buf[0] >> 5) == 0 && buf[4] == 0) {
+        return 256;
+    } else {
+        return scsi_cdb_length(buf);
+    }
+}
+
+uint32_t scsi_cdb_length(uint8_t *buf)
 {
     switch (buf[0] >> 5) {
     case 0:
-        cmd->xfer = buf[4];
+        return buf[4];
         break;
     case 1:
     case 2:
-        cmd->xfer = lduw_be_p(&buf[7]);
+        return lduw_be_p(&buf[7]);
         break;
     case 4:
-        cmd->xfer = ldl_be_p(&buf[10]) & 0xffffffffULL;
+        return ldl_be_p(&buf[10]) & 0xffffffffULL;
         break;
     case 5:
-        cmd->xfer = ldl_be_p(&buf[6]) & 0xffffffffULL;
+        return ldl_be_p(&buf[6]) & 0xffffffffULL;
         break;
     default:
         return -1;
     }
+}
 
+static int scsi_req_length(SCSICommand *cmd, SCSIDevice *dev, uint8_t *buf)
+{
+    cmd->xfer = scsi_cdb_length(buf);
     switch (buf[0]) {
     case TEST_UNIT_READY:
     case REWIND:
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index 1585683bce..95e91585e6 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -678,7 +678,7 @@ static int scsi_disk_emulate_inquiry(SCSIRequest *req, uint8_t *outbuf)
      * is actually implemented, but we're good enough.
      */
     outbuf[2] = 5;
-    outbuf[3] = 2; /* Format 2 */
+    outbuf[3] = 2 | 0x10; /* Format 2, HiSup */
 
     if (buflen > 36) {
         outbuf[4] = buflen - 5; /* Additional Length = (Len - 1) - 4 */
@@ -1449,6 +1449,22 @@ invalid_field:
     return;
 }
 
+static inline bool check_lba_range(SCSIDiskState *s,
+                                   uint64_t sector_num, uint32_t nb_sectors)
+{
+    /*
+     * The first line tests that no overflow happens when computing the last
+     * sector.  The second line tests that the last accessed sector is in
+     * range.
+     *
+     * Careful, the computations should not underflow for nb_sectors == 0,
+     * and a 0-block read to the first LBA beyond the end of device is
+     * valid.
+     */
+    return (sector_num <= sector_num + nb_sectors &&
+            sector_num + nb_sectors <= s->qdev.max_lba + 1);
+}
+
 typedef struct UnmapCBData {
     SCSIDiskReq *r;
     uint8_t *inbuf;
@@ -1473,8 +1489,7 @@ static void scsi_unmap_complete(void *opaque, int ret)
     if (data->count > 0 && !r->req.io_canceled) {
         sector_num = ldq_be_p(&data->inbuf[0]);
         nb_sectors = ldl_be_p(&data->inbuf[8]) & 0xffffffffULL;
-        if (sector_num > sector_num + nb_sectors ||
-            sector_num + nb_sectors - 1 > s->qdev.max_lba) {
+        if (!check_lba_range(s, sector_num, nb_sectors)) {
             scsi_check_condition(r, SENSE_CODE(LBA_OUT_OF_RANGE));
             goto done;
         }
@@ -1793,17 +1808,13 @@ static int32_t scsi_disk_emulate_command(SCSIRequest *req, uint8_t *buf)
         DPRINTF("Unmap (len %lu)\n", (long)r->req.cmd.xfer);
         break;
     case WRITE_SAME_10:
-        nb_sectors = lduw_be_p(&req->cmd.buf[7]);
-        goto write_same;
     case WRITE_SAME_16:
-        nb_sectors = ldl_be_p(&req->cmd.buf[10]) & 0xffffffffULL;
-    write_same:
+        nb_sectors = scsi_data_cdb_length(r->req.cmd.buf);
         if (bdrv_is_read_only(s->qdev.conf.bs)) {
             scsi_check_condition(r, SENSE_CODE(WRITE_PROTECTED));
             return 0;
         }
-        if (r->req.cmd.lba > r->req.cmd.lba + nb_sectors ||
-            r->req.cmd.lba + nb_sectors - 1 > s->qdev.max_lba) {
+        if (!check_lba_range(s, r->req.cmd.lba, nb_sectors)) {
             goto illegal_lba;
         }
 
@@ -1858,7 +1869,7 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf)
 {
     SCSIDiskReq *r = DO_UPCAST(SCSIDiskReq, req, req);
     SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, req->dev);
-    int32_t len;
+    uint32_t len;
     uint8_t command;
 
     command = buf[0];
@@ -1868,18 +1879,17 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf)
         return 0;
     }
 
+    len = scsi_data_cdb_length(r->req.cmd.buf);
     switch (command) {
     case READ_6:
     case READ_10:
     case READ_12:
     case READ_16:
-        len = r->req.cmd.xfer / s->qdev.blocksize;
-        DPRINTF("Read (sector %" PRId64 ", count %d)\n", r->req.cmd.lba, len);
+        DPRINTF("Read (sector %" PRId64 ", count %u)\n", r->req.cmd.lba, len);
         if (r->req.cmd.buf[1] & 0xe0) {
             goto illegal_request;
         }
-        if (r->req.cmd.lba > r->req.cmd.lba + len ||
-            r->req.cmd.lba + len - 1 > s->qdev.max_lba) {
+        if (!check_lba_range(s, r->req.cmd.lba, len)) {
             goto illegal_lba;
         }
         r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
@@ -1900,15 +1910,13 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf)
     case VERIFY_10:
     case VERIFY_12:
     case VERIFY_16:
-        len = r->req.cmd.xfer / s->qdev.blocksize;
-        DPRINTF("Write %s(sector %" PRId64 ", count %d)\n",
+        DPRINTF("Write %s(sector %" PRId64 ", count %u)\n",
                 (command & 0xe) == 0xe ? "And Verify " : "",
                 r->req.cmd.lba, len);
         if (r->req.cmd.buf[1] & 0xe0) {
             goto illegal_request;
         }
-        if (r->req.cmd.lba > r->req.cmd.lba + len ||
-            r->req.cmd.lba + len - 1 > s->qdev.max_lba) {
+        if (!check_lba_range(s, r->req.cmd.lba, len)) {
             goto illegal_lba;
         }
         r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
diff --git a/hw/scsi.h b/hw/scsi.h
index 1aeee4659c..b8f73577d3 100644
--- a/hw/scsi.h
+++ b/hw/scsi.h
@@ -218,6 +218,8 @@ extern const struct SCSISense sense_code_WRITE_PROTECTED;
 
 #define SENSE_CODE(x) sense_code_ ## x
 
+uint32_t scsi_data_cdb_length(uint8_t *buf);
+uint32_t scsi_cdb_length(uint8_t *buf);
 int scsi_sense_valid(SCSISense sense);
 int scsi_build_sense(uint8_t *in_buf, int in_len,
                      uint8_t *buf, int len, bool fixed);