virtio-blk: pass full status to the guest

When SCSI passthrough is being used by the guest with virtio-blk, the
guest is not able to detect disk failures.  This is because the status
field is expected by the guest driver to include also the msg_status,
host_status and driver_status fields, but the device is only passing
down the SCSI status.

The patch fixes this, and also makes sure that the guest always sees a
CHECK_CONDITION status when there is valid sense data.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Paolo Bonzini 2011-11-02 13:19:40 +01:00 committed by Anthony Liguori
parent e072ea2fd8
commit 5bb2392776

View File

@ -16,6 +16,7 @@
#include "trace.h"
#include "blockdev.h"
#include "virtio-blk.h"
#include "scsi-defs.h"
#ifdef __linux__
# include <scsi/sg.h>
#endif
@ -231,7 +232,20 @@ static void virtio_blk_handle_scsi(VirtIOBlockReq *req)
status = VIRTIO_BLK_S_OK;
}
stl_p(&req->scsi->errors, hdr.status);
/*
* From SCSI-Generic-HOWTO: "Some lower level drivers (e.g. ide-scsi)
* clear the masked_status field [hence status gets cleared too, see
* block/scsi_ioctl.c] even when a CHECK_CONDITION or COMMAND_TERMINATED
* status has occurred. However they do set DRIVER_SENSE in driver_status
* field. Also a (sb_len_wr > 0) indicates there is a sense buffer.
*/
if (hdr.status == 0 && hdr.sb_len_wr > 0) {
hdr.status = CHECK_CONDITION;
}
stl_p(&req->scsi->errors,
hdr.status | (hdr.msg_status << 8) |
(hdr.host_status << 16) | (hdr.driver_status << 24));
stl_p(&req->scsi->residual, hdr.resid);
stl_p(&req->scsi->sense_len, hdr.sb_len_wr);
stl_p(&req->scsi->data_len, hdr.dxfer_len);