virtio-ccw: fix ring sizing

Current code seems to assume ring size is
always decreased but this is not required by spec:
what spec says is just that size can not exceed
the maximum. Fix it up.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <1484256243-1982-1-git-send-email-mst@redhat.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
master
Michael S. Tsirkin 2017-01-12 23:26:22 +02:00 committed by Cornelia Huck
parent 857cc71985
commit 8c797e758a
3 changed files with 7 additions and 1 deletions

View File

@ -149,7 +149,7 @@ static int virtio_ccw_set_vqs(SubchDev *sch, VqInfoBlock *info,
} else {
if (info) {
/* virtio-1 allows changing the ring size. */
if (virtio_queue_get_num(vdev, index) < num) {
if (virtio_queue_get_max_num(vdev, index) < num) {
/* Fail if we exceed the maximum number. */
return -EINVAL;
}

View File

@ -1262,6 +1262,11 @@ int virtio_queue_get_num(VirtIODevice *vdev, int n)
return vdev->vq[n].vring.num;
}
int virtio_queue_get_max_num(VirtIODevice *vdev, int n)
{
return vdev->vq[n].vring.num_default;
}
int virtio_get_num_queues(VirtIODevice *vdev)
{
int i;

View File

@ -228,6 +228,7 @@ void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr);
hwaddr virtio_queue_get_addr(VirtIODevice *vdev, int n);
void virtio_queue_set_num(VirtIODevice *vdev, int n, int num);
int virtio_queue_get_num(VirtIODevice *vdev, int n);
int virtio_queue_get_max_num(VirtIODevice *vdev, int n);
int virtio_get_num_queues(VirtIODevice *vdev);
void virtio_queue_set_rings(VirtIODevice *vdev, int n, hwaddr desc,
hwaddr avail, hwaddr used);