vhost_net: don't set backend for the uninitialized virtqueue

We used to set backend unconditionally, this won't work for some
guests (e.g windows driver) who may not initialize all virtqueues. For
kernel backend, this will fail since it may try to validate the rings
during setting backend.

Fixing this by simply skipping the backend set when we find desc is
not ready.

Reviewed-by: Michael S. Tsirkin<mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Jason Wang 2019-03-25 11:40:36 +08:00
parent d8276573da
commit 23bfaf77fa
3 changed files with 16 additions and 0 deletions

View file

@ -244,6 +244,11 @@ static int vhost_net_start_one(struct vhost_net *net,
qemu_set_fd_handler(net->backend, NULL, NULL, NULL);
file.fd = net->backend;
for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
if (!virtio_queue_enabled(dev, net->dev.vq_index +
file.index)) {
/* Queue might not be ready for start */
continue;
}
r = vhost_net_set_backend(&net->dev, &file);
if (r < 0) {
r = -errno;
@ -256,6 +261,11 @@ fail:
file.fd = -1;
if (net->nc->info->type == NET_CLIENT_DRIVER_TAP) {
while (file.index-- > 0) {
if (!virtio_queue_enabled(dev, net->dev.vq_index +
file.index)) {
/* Queue might not be ready for start */
continue;
}
int r = vhost_net_set_backend(&net->dev, &file);
assert(r >= 0);
}