virtio-scsi: Report missed events

When an event is reported but no buffers are present in the event vq,
we can set a flag and report a dummy event as soon as one is added.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2012-07-02 10:47:35 +02:00
parent b6866fee58
commit 64f64855d0

View file

@ -141,6 +141,7 @@ typedef struct {
uint32_t sense_size;
uint32_t cdb_size;
int resetting;
bool events_dropped;
VirtQueue *ctrl_vq;
VirtQueue *event_vq;
VirtQueue *cmd_vqs[0];
@ -416,10 +417,6 @@ static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
}
}
static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
{
}
static void virtio_scsi_command_complete(SCSIRequest *r, uint32_t status,
size_t resid)
{
@ -594,22 +591,34 @@ static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
{
VirtIOSCSIReq *req = virtio_scsi_pop_req(s, s->event_vq);
VirtIOSCSIEvent *evt;
int in_size;
if (req) {
int in_size;
if (req->elem.out_num || req->elem.in_num != 1) {
virtio_scsi_bad_req();
}
if (!req) {
s->events_dropped = true;
return;
}
in_size = req->elem.in_sg[0].iov_len;
if (in_size < sizeof(VirtIOSCSIEvent)) {
virtio_scsi_bad_req();
}
if (req->elem.out_num || req->elem.in_num != 1) {
virtio_scsi_bad_req();
}
evt = req->resp.event;
memset(evt, 0, sizeof(VirtIOSCSIEvent));
evt->event = event;
evt->reason = reason;
if (s->events_dropped) {
event |= VIRTIO_SCSI_T_EVENTS_MISSED;
s->events_dropped = false;
}
in_size = req->elem.in_sg[0].iov_len;
if (in_size < sizeof(VirtIOSCSIEvent)) {
virtio_scsi_bad_req();
}
evt = req->resp.event;
memset(evt, 0, sizeof(VirtIOSCSIEvent));
evt->event = event;
evt->reason = reason;
if (!dev) {
assert(event == VIRTIO_SCSI_T_NO_EVENT);
} else {
evt->lun[0] = 1;
evt->lun[1] = dev->id;
@ -618,7 +627,16 @@ static void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
evt->lun[2] = (dev->lun >> 8) | 0x40;
}
evt->lun[3] = dev->lun & 0xFF;
virtio_scsi_complete_req(req);
}
virtio_scsi_complete_req(req);
}
static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOSCSI *s = (VirtIOSCSI *)vdev;
if (s->events_dropped) {
virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
}
}