scsi-disk: improve the lba-out-of-range tests for read/write/verify

Improve the tests for the LBA to cover more cases.

For the 16 byte opcodes, the lba is a uint64, so we need to check is to
make sure that we do not wrap.  For example if an opcode would specify
the LBA:0xffffffffffffffff and LEN:2 then lba+len would wrap to 1.

Also verify that ALL requested blocks are available, not just the first one.
Signed-off-by: NRonnie Sahlberg <ronniesahlberg@gmail.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

hw/scsi-disk.c

@@ -1777,7 +1777,8 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf)
         if (r->req.cmd.buf[1] & 0xe0) {
             goto illegal_request;
         }
-        if (r->req.cmd.lba > s->qdev.max_lba) {
+        if (r->req.cmd.lba > r->req.cmd.lba + len ||
+            r->req.cmd.lba + len - 1 > s->qdev.max_lba) {
             goto illegal_lba;
         }
         r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);
@@ -1800,7 +1801,8 @@ static int32_t scsi_disk_dma_command(SCSIRequest *req, uint8_t *buf)
         if (r->req.cmd.buf[1] & 0xe0) {
             goto illegal_request;
         }
-        if (r->req.cmd.lba > s->qdev.max_lba) {
+        if (r->req.cmd.lba > r->req.cmd.lba + len ||
+            r->req.cmd.lba + len - 1 > s->qdev.max_lba) {
             goto illegal_lba;
         }
         r->sector = r->req.cmd.lba * (s->qdev.blocksize / 512);