From: liujunjie <liujunji...@huawei.com> Before, we did not clear callback like handle_output when delete the virtqueue which may result be segmentfault. The scene is as follows: 1. Start a vm with multiqueue vhost-net, 2. then we write VIRTIO_PCI_GUEST_FEATURES in PCI configuration to triger multiqueue disable in this vm which will delete the virtqueue. In this step, the tx_bh is deleted but the callback virtio_net_handle_tx_bh still exist. 3. Finally, we write VIRTIO_PCI_QUEUE_NOTIFY in PCI configuration to notify the deleted virtqueue. In this way, virtio_net_handle_tx_bh will be called and qemu will be crashed.
Although the way described above is uncommon, we had better reinforce it. CC: qemu-sta...@nongnu.org Signed-off-by: liujunjie <liujunji...@huawei.com> Signed-off-by: Jason Wang <jasow...@redhat.com> (cherry picked from commit 7da2d99fb9fbf30104125c061caaff330e362d74) Signed-off-by: Michael Roth <mdr...@linux.vnet.ibm.com> --- hw/virtio/virtio.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index f6a588ab57..57a603a65b 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -1604,6 +1604,8 @@ void virtio_del_queue(VirtIODevice *vdev, int n) vdev->vq[n].vring.num = 0; vdev->vq[n].vring.num_default = 0; + vdev->vq[n].handle_output = NULL; + vdev->vq[n].handle_aio_output = NULL; } static void virtio_set_isr(VirtIODevice *vdev, int value) -- 2.17.1