scsi: establish precedence levels for unit attention

When a device is resized, we will report a unit attention condition
for CAPACITY DATA HAS CHANGED.  However, we should ensure that this
condition does not override a more important unit attention condition.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2012-07-16 14:18:58 +02:00
parent 350e6e4199
commit e48e84ea80
4 changed files with 55 additions and 3 deletions

View File

@ -1531,6 +1531,55 @@ void scsi_req_abort(SCSIRequest *req, int status)
scsi_req_unref(req);
}
static int scsi_ua_precedence(SCSISense sense)
{
if (sense.key != UNIT_ATTENTION) {
return INT_MAX;
}
if (sense.asc == 0x29 && sense.ascq == 0x04) {
/* DEVICE INTERNAL RESET goes with POWER ON OCCURRED */
return 1;
} else if (sense.asc == 0x3F && sense.ascq == 0x01) {
/* MICROCODE HAS BEEN CHANGED goes with SCSI BUS RESET OCCURRED */
return 2;
} else if (sense.asc == 0x29 && (sense.ascq == 0x05 || sense.ascq == 0x06)) {
/* These two go with "all others". */
;
} else if (sense.asc == 0x29 && sense.ascq <= 0x07) {
/* POWER ON, RESET OR BUS DEVICE RESET OCCURRED = 0
* POWER ON OCCURRED = 1
* SCSI BUS RESET OCCURRED = 2
* BUS DEVICE RESET FUNCTION OCCURRED = 3
* I_T NEXUS LOSS OCCURRED = 7
*/
return sense.ascq;
} else if (sense.asc == 0x2F && sense.ascq == 0x01) {
/* COMMANDS CLEARED BY POWER LOSS NOTIFICATION */
return 8;
}
return (sense.asc << 8) | sense.ascq;
}
void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense)
{
int prec1, prec2;
if (sense.key != UNIT_ATTENTION) {
return;
}
trace_scsi_device_set_ua(sdev->id, sdev->lun, sense.key,
sense.asc, sense.ascq);
/*
* Override a pre-existing unit attention condition, except for a more
* important reset condition.
*/
prec1 = scsi_ua_precedence(sdev->unit_attention);
prec2 = scsi_ua_precedence(sense);
if (prec2 < prec1) {
sdev->unit_attention = sense;
}
}
void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
{
SCSIRequest *req;
@ -1539,7 +1588,8 @@ void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense)
req = QTAILQ_FIRST(&sdev->requests);
scsi_req_cancel(req);
}
sdev->unit_attention = sense;
scsi_device_set_ua(sdev, sense);
}
static char *scsibus_get_dev_path(DeviceState *dev)

View File

@ -1876,7 +1876,7 @@ static void scsi_cd_change_media_cb(void *opaque, bool load)
*/
s->media_changed = load;
s->tray_open = !load;
s->qdev.unit_attention = SENSE_CODE(UNIT_ATTENTION_NO_MEDIUM);
scsi_device_set_ua(&s->qdev, SENSE_CODE(UNIT_ATTENTION_NO_MEDIUM));
s->media_event = true;
s->eject_request = false;
}
@ -1913,7 +1913,7 @@ static void scsi_disk_unit_attention_reported(SCSIDevice *dev)
SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, dev);
if (s->media_changed) {
s->media_changed = false;
s->qdev.unit_attention = SENSE_CODE(MEDIUM_CHANGED);
scsi_device_set_ua(&s->qdev, SENSE_CODE(MEDIUM_CHANGED));
}
}

View File

@ -239,6 +239,7 @@ void scsi_req_abort(SCSIRequest *req, int status);
void scsi_req_cancel(SCSIRequest *req);
void scsi_req_retry(SCSIRequest *req);
void scsi_device_purge_requests(SCSIDevice *sdev, SCSISense sense);
void scsi_device_set_ua(SCSIDevice *sdev, SCSISense sense);
int scsi_device_get_sense(SCSIDevice *dev, uint8_t *buf, int len, bool fixed);
SCSIDevice *scsi_device_find(SCSIBus *bus, int channel, int target, int lun);

View File

@ -412,6 +412,7 @@ scsi_req_parsed(int target, int lun, int tag, int cmd, int mode, int xfer) "targ
scsi_req_parsed_lba(int target, int lun, int tag, int cmd, uint64_t lba) "target %d lun %d tag %d command %d lba %"PRIu64
scsi_req_parse_bad(int target, int lun, int tag, int cmd) "target %d lun %d tag %d command %d"
scsi_req_build_sense(int target, int lun, int tag, int key, int asc, int ascq) "target %d lun %d tag %d key %#02x asc %#02x ascq %#02x"
scsi_device_set_ua(int target, int lun, int key, int asc, int ascq) "target %d lun %d key %#02x asc %#02x ascq %#02x"
scsi_report_luns(int target, int lun, int tag) "target %d lun %d tag %d"
scsi_inquiry(int target, int lun, int tag, int cdb1, int cdb2) "target %d lun %d tag %d page %#02x/%#02x"
scsi_test_unit_ready(int target, int lun, int tag) "target %d lun %d tag %d"