Guest state should not be touched if VM is stopped, unfortunately we
didn't check running state and tried to drain tx queue unconditionally
in virtio_net_set_status(). A crash was then noticed as a migration
destination when user type quit after virtqueue state is loaded but
before region cache is initialized. In this case,
virtio_net_drop_tx_queue_data() tries to access the uninitialized
region cache.
Fix this by only dropping tx queue data when vm is running.
Fixes: 283e2c2adcb80 ("net: virtio-net discards TX data after link down")
Cc: Yuri Benditovich <yuri.benditov...@daynix.com>
Cc: Paolo Bonzini <pbonz...@redhat.com>
Cc: Stefan Hajnoczi <stefa...@redhat.com>
Cc: Michael S. Tsirkin <m...@redhat.com>
Cc: qemu-sta...@nongnu.org
Signed-off-by: Jason Wang <jasow...@redhat.com>
---
hw/net/virtio-net.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 150fd07..38674b0 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -288,7 +288,8 @@ static void virtio_net_set_status(struct VirtIODevice
*vdev, uint8_t status)
qemu_bh_cancel(q->tx_bh);
}
if ((n->status & VIRTIO_NET_S_LINK_UP) == 0 &&
- (queue_status & VIRTIO_CONFIG_S_DRIVER_OK)) {
+ (queue_status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+ vdev->vm_running) {
/* if tx is waiting we are likely have some packets in tx queue
* and disabled notification */
q->tx_waiting = 0;
--
2.7.4
