CD burning commands do strange things including writing beyond the
maximum LBA and even to negative blocks for the lead-in.
WRITE(6), WRITE(16), WRITE AND VERIFY(16) are not in MMC.
WRITE AND VERIFY(12) is not in MMC but it seemed a good idea to
treat it like WRITE(12).
Also detect blanking of a disc and reset the maximum LBA. It's possible
that more special casing is necessary, e.g. for track-at-once, since
those do not start with blanking.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
hw/scsi-disk.c | 18 +++++++++++++-----
hw/scsi-generic.c | 5 +++++
2 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/hw/scsi-disk.c b/hw/scsi-disk.c
index 19e846c..f18a9e6 100644
--- a/hw/scsi-disk.c
+++ b/hw/scsi-disk.c
@@ -1755,17 +1755,25 @@ static SCSIRequest *scsi_block_new_request(SCSIDevice
*d, uint32_t tag,
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, d);
switch (buf[0]) {
- case READ_6:
- case READ_10:
- case READ_12:
- case READ_16:
- case WRITE_6:
case WRITE_10:
case WRITE_12:
+ case WRITE_VERIFY_10:
+ case WRITE_VERIFY_12:
+ /* Detect if writing the lead-in of a CD, which is represented by
+ * negative LBA addresses. If so, just pass through. Also,
+ * when burning the maximum LBA is zero. Play it safe and pass
+ * those writes through as well. */
+ if (s->qdev.type == TYPE_ROM && (s->qdev.max_lba == 0 || buf[2] >
0x7F)) {
+ break;
+ }
+
+ case WRITE_6:
case WRITE_16:
- case WRITE_VERIFY_10:
- case WRITE_VERIFY_12:
case WRITE_VERIFY_16:
+ case READ_6:
+ case READ_10:
+ case READ_12:
+ case READ_16:
return scsi_req_alloc(&scsi_disk_reqops, &s->qdev, tag, lun,
hba_private);
}
diff --git a/hw/scsi-generic.c b/hw/scsi-generic.c
index a86e5a8..fb34a33 100644
--- a/hw/scsi-generic.c
+++ b/hw/scsi-generic.c
@@ -236,6 +236,11 @@ static void scsi_read_complete(void * opaque, int ret)
}
bdrv_set_buffer_alignment(s->conf.bs, s->blocksize);
+ /* ... and BLANK to update the maximum LBA. */
+ if (s->type == TYPE_ROM && r->req.cmd.buf[0] == BLANK) {
+ s->max_lba = 0;
+ }
+
scsi_req_data(&r->req, len);
if (!r->req.io_canceled) {
scsi_req_unref(&r->req);
--
1.7.7.1
