| Message ID | 20171116184835.28556-2-maxime.coquelin@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | virtio-net: Fix TX data discard on backend disconnection | expand |
On Thu, Nov 16, 2017 at 06:48:34PM +0000, Maxime Coquelin wrote: >In case of backend crash, it is not possible to restore internal >avail index from the backend value as vhost_get_vring_base >callback fails. > >This patch provides a new interface to restore internal avail index >from the vring used index, as done by some vhost-user backend on >reconnection. > >Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com> >--- > hw/virtio/virtio.c | 10 ++++++++++ > include/hw/virtio/virtio.h | 1 + > 2 files changed, 11 insertions(+) > Reviewed-by: Jens Freimann <jfreimann@redhat.com>
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 5884ce3480..583516c428 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -2310,6 +2310,16 @@ void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx) vdev->vq[n].shadow_avail_idx = idx; } +void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n) +{ + rcu_read_lock(); + if (vdev->vq[n].vring.desc) { + vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]); + vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx; + } + rcu_read_unlock(); +} + void virtio_queue_update_used_idx(VirtIODevice *vdev, int n) { rcu_read_lock(); diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 5abada6966..098bdaaea3 100644 --- a/include/hw/virtio/virtio.h +++ b/include/hw/virtio/virtio.h @@ -272,6 +272,7 @@ hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n); hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n); uint16_t virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n); void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n, uint16_t idx); +void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n); void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n); void virtio_queue_update_used_idx(VirtIODevice *vdev, int n); VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
In case of backend crash, it is not possible to restore internal avail index from the backend value as vhost_get_vring_base callback fails. This patch provides a new interface to restore internal avail index from the vring used index, as done by some vhost-user backend on reconnection. Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com> --- hw/virtio/virtio.c | 10 ++++++++++ include/hw/virtio/virtio.h | 1 + 2 files changed, 11 insertions(+)