haraldwolff
/
qemu-patch-raspberry4
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

virtio: Add queue interface to restore avail index from vring used index 

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>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
stable-2.11
Maxime Coquelin 2017-11-16 19:48:34 +01:00 committed by Michael S. Tsirkin
parent 861fec459b
commit 2d4ba6cc74
2 changed files with 11 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
hw/virtio/virtio.c
View File

@ -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();

1
include/hw/virtio/virtio.h
View File

@ -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);