virtio-scsi: suppress virtqueue kick during processing
The guest does not need to kick the virtqueue while we are processing it. This reduces the number of vmexits during periods of heavy I/O. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 20161201192652.9509-9-stefanha@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
parent
9ef9d40261
commit
23425cc2b7
|
@ -592,10 +592,13 @@ static void virtio_scsi_handle_cmd_req_submit(VirtIOSCSI *s, VirtIOSCSIReq *req)
|
|||
void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
|
||||
{
|
||||
VirtIOSCSIReq *req, *next;
|
||||
int ret;
|
||||
int ret = 0;
|
||||
|
||||
QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
|
||||
|
||||
do {
|
||||
virtio_queue_set_notification(vq, 0);
|
||||
|
||||
while ((req = virtio_scsi_pop_req(s, vq))) {
|
||||
ret = virtio_scsi_handle_cmd_req_prepare(s, req);
|
||||
if (!ret) {
|
||||
|
@ -613,6 +616,9 @@ void virtio_scsi_handle_cmd_vq(VirtIOSCSI *s, VirtQueue *vq)
|
|||
}
|
||||
}
|
||||
|
||||
virtio_queue_set_notification(vq, 1);
|
||||
} while (ret != -EINVAL && !virtio_queue_empty(vq));
|
||||
|
||||
QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
|
||||
virtio_scsi_handle_cmd_req_submit(s, req);
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue