virtio-net: don't run bh on vm stopped

commit 783e770693
    virtio-net: stop/start bh when appropriate

is incomplete: BH might execute within the same main loop iteration but
after vmstop, so in theory, we might trigger an assertion.
I was unable to reproduce this in practice,
but it seems clear enough that the potential is there, so worth fixing.

Cc: qemu-stable@nongnu.org
Reported-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2014-09-02 16:12:41 +03:00
parent fc8342f758
commit 0187c7989a

View File

@ -1224,7 +1224,12 @@ static void virtio_net_tx_timer(void *opaque)
VirtIONetQueue *q = opaque;
VirtIONet *n = q->n;
VirtIODevice *vdev = VIRTIO_DEVICE(n);
assert(vdev->vm_running);
/* This happens when device was stopped but BH wasn't. */
if (!vdev->vm_running) {
/* Make sure tx waiting is set, so we'll run when restarted. */
assert(q->tx_waiting);
return;
}
q->tx_waiting = 0;
@ -1244,7 +1249,12 @@ static void virtio_net_tx_bh(void *opaque)
VirtIODevice *vdev = VIRTIO_DEVICE(n);
int32_t ret;
assert(vdev->vm_running);
/* This happens when device was stopped but BH wasn't. */
if (!vdev->vm_running) {
/* Make sure tx waiting is set, so we'll run when restarted. */
assert(q->tx_waiting);
return;
}
q->tx_waiting = 0;