On Wed, Oct 21, 2015 at 11:19:14AM +0200, Thibaut Collet wrote:
> When a live migration is started the log address to mark dirty pages is
> provided
> to the vhost backend through the vhost_dev_set_log function.
> This function is called for each queue pairs but the queue index provided to
> the
> vhost_virtqueue_set_addr function is wrongly set: always set to the first
> queue
> pair. Then vhost backend lost descriptor addresses of the queue pairs greater
> than 1 and behaviour of the vhost backend is unpredictable.
>
> The vhost_dev_set_log is modified to provide the correct queue index to the
> vhost_virtqueue_set_addr function that calls internally the vhost_get_vq_index
> to compute the expected vhost_vq_index for vhost kernel and vhost user.
> This change implies a modification of the vhost_virtqueue_start function to
> provide the index and not the vhost_vq_index.
>
> Signed-off-by: Thibaut Collet <thibaut.col...@6wind.com>
I applied v1 already, please post a patch on top.
> ---
> hw/virtio/vhost.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index feeaaa4..9311832 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -628,8 +628,9 @@ static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
> struct vhost_virtqueue *vq,
> unsigned idx, bool enable_log)
> {
> + int vhost_vq_index = dev->vhost_ops->vhost_get_vq_index(dev, idx);
> struct vhost_vring_addr addr = {
> - .index = idx,
> + .index = vhost_vq_index,
> .desc_user_addr = (uint64_t)(unsigned long)vq->desc,
> .avail_user_addr = (uint64_t)(unsigned long)vq->avail,
> .used_user_addr = (uint64_t)(unsigned long)vq->used,
> @@ -662,7 +663,7 @@ static int vhost_dev_set_log(struct vhost_dev *dev, bool
> enable_log)
> goto err_features;
> }
> for (i = 0; i < dev->nvqs; ++i) {
> - r = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
> + r = vhost_virtqueue_set_addr(dev, dev->vqs + i, dev->vq_index + i,
> enable_log);
> if (r < 0) {
> goto err_vq;
> @@ -671,7 +672,7 @@ static int vhost_dev_set_log(struct vhost_dev *dev, bool
> enable_log)
> return 0;
> err_vq:
> for (; i >= 0; --i) {
> - t = vhost_virtqueue_set_addr(dev, dev->vqs + i, i,
> + t = vhost_virtqueue_set_addr(dev, dev->vqs + i, dev->vq_index + i,
> dev->log_enabled);
> assert(t >= 0);
> }
> @@ -836,7 +837,7 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
> goto fail_alloc_ring;
> }
>
> - r = vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabled);
> + r = vhost_virtqueue_set_addr(dev, vq, idx, dev->log_enabled);
> if (r < 0) {
> r = -errno;
> goto fail_alloc;
> --
> 2.1.4
