mirrors/qemu
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

virtio-net: Flush incoming queues when DRIVER_OK is being set

Browse Source 
This patch fixes network hang after "stop" then "cont", while network
packets keep arriving.

Tested both manually (tap, host pinging guest) and with Jason's qtest
series (plus his "[PATCH 2.4] socket: pass correct size in
net_socket_send()" fix).

As virtio_net_set_status is called when guest driver is setting status
byte and when vm state is changing, it is a good opportunity to flush
queued packets.

This is necessary because during vm stop the backend (e.g. tap) would
stop rx processing after .can_receive returns false, until the queue is
explicitly flushed or purged.

The other interesting condition in .can_receive, virtio_queue_ready(),
is handled by virtio_net_handle_rx() when guest kicks; the 3rd condition
is invalid queue index which doesn't need flushing.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Fam Zheng 2015-07-15 11:02:27 +08:00 committed by Michael S. Tsirkin
parent 9a2a66238e
commit 38705bb57b
1 changed files with 9 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
hw/net/virtio-net.c
View File

@ -162,6 +162,8 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
virtio_net_vhost_status(n, status);
for (i = 0; i < n->max_queues; i++) {
NetClientState *ncs = qemu_get_subqueue(n->nic, i);
bool queue_started;
q = &n->vqs[i];
if ((!n->multiqueue && i != 0) || i >= n->curr_queues) {
@ -169,12 +171,18 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
} else {
queue_status = status;
}
queue_started =
virtio_net_started(n, queue_status) && !n->vhost_started;
if (queue_started) {
qemu_flush_queued_packets(ncs);
}
if (!q->tx_waiting) {
continue;
}
if (virtio_net_started(n, queue_status) && !n->vhost_started) {
if (queue_started) {
if (q->tx_timer) {
timer_mod(q->tx_timer,
qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + n->tx_timeout);