vhost: break out of polling loop on error
When ring parsing fails, we currently handle this
as ring empty condition. This means that we enable
kicks and recheck ring empty: if this not empty,
we re-start polling which of course will fail again.
Instead, let's return a negative error code and stop polling.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 0f41c91..54096ee 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -98,7 +98,8 @@
static void handle_tx(struct vhost_net *net)
{
struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_TX];
- unsigned head, out, in, s;
+ unsigned out, in, s;
+ int head;
struct msghdr msg = {
.msg_name = NULL,
.msg_namelen = 0,
@@ -135,6 +136,9 @@
ARRAY_SIZE(vq->iov),
&out, &in,
NULL, NULL);
+ /* On error, stop handling until the next kick. */
+ if (head < 0)
+ break;
/* Nothing new? Wait for eventfd to tell us they refilled. */
if (head == vq->num) {
wmem = atomic_read(&sock->sk->sk_wmem_alloc);
@@ -192,7 +196,8 @@
static void handle_rx(struct vhost_net *net)
{
struct vhost_virtqueue *vq = &net->dev.vqs[VHOST_NET_VQ_RX];
- unsigned head, out, in, log, s;
+ unsigned out, in, log, s;
+ int head;
struct vhost_log *vq_log;
struct msghdr msg = {
.msg_name = NULL,
@@ -228,6 +233,9 @@
ARRAY_SIZE(vq->iov),
&out, &in,
vq_log, &log);
+ /* On error, stop handling until the next kick. */
+ if (head < 0)
+ break;
/* OK, now we need to know about added descriptors. */
if (head == vq->num) {
if (unlikely(vhost_enable_notify(vq))) {