Re: [PATCH v4 2/7] vhost: check queue state in the vhost_dev_set_log routine

[Raphael Norwitz]

On Fri, Sep 4, 2020 at 5:32 AM Dima Stepanov  wrote:
>
> If the vhost-user-blk daemon provides only one virtqueue, but device was
> added with several queues, then QEMU will send more VHOST-USER command
> than expected by daemon side. The vhost_virtqueue_start() routine
> handles such case by checking the return value from the
> virtio_queue_get_desc_addr() function call. Add the same check to the
> vhost_dev_set_log() routine.
>
> Signed-off-by: Dima Stepanov 

Reviewed-by: Raphael Norwitz 


> ---
>  hw/virtio/vhost.c | 12 
>  1 file changed, 12 insertions(+)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index ffef7ab..a08b7d8 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -825,12 +825,24 @@ static int vhost_dev_set_features(struct vhost_dev *dev,
>  static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log)
>  {
>  int r, i, idx;
> +hwaddr addr;
> +
>  r = vhost_dev_set_features(dev, enable_log);
>  if (r < 0) {
>  goto err_features;
>  }
>  for (i = 0; i < dev->nvqs; ++i) {
>  idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i);
> +addr = virtio_queue_get_desc_addr(dev->vdev, idx);
> +if (!addr) {
> +/*
> + * The queue might not be ready for start. If this
> + * is the case there is no reason to continue the process.
> + * The similar logic is used by the vhost_virtqueue_start()
> + * routine.
> + */
> +continue;
> +}
>  r = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx,
>   enable_log);
>  if (r < 0) {
> --
> 2.7.4
>
>

[PATCH v4 2/7] vhost: check queue state in the vhost_dev_set_log routine

[Dima Stepanov]

If the vhost-user-blk daemon provides only one virtqueue, but device was
added with several queues, then QEMU will send more VHOST-USER command
than expected by daemon side. The vhost_virtqueue_start() routine
handles such case by checking the return value from the
virtio_queue_get_desc_addr() function call. Add the same check to the
vhost_dev_set_log() routine.

Signed-off-by: Dima Stepanov 
---
 hw/virtio/vhost.c | 12 
 1 file changed, 12 insertions(+)

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index ffef7ab..a08b7d8 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -825,12 +825,24 @@ static int vhost_dev_set_features(struct vhost_dev *dev,
 static int vhost_dev_set_log(struct vhost_dev *dev, bool enable_log)
 {
 int r, i, idx;
+hwaddr addr;
+
 r = vhost_dev_set_features(dev, enable_log);
 if (r < 0) {
 goto err_features;
 }
 for (i = 0; i < dev->nvqs; ++i) {
 idx = dev->vhost_ops->vhost_get_vq_index(dev, dev->vq_index + i);
+addr = virtio_queue_get_desc_addr(dev->vdev, idx);
+if (!addr) {
+/*
+ * The queue might not be ready for start. If this
+ * is the case there is no reason to continue the process.
+ * The similar logic is used by the vhost_virtqueue_start()
+ * routine.
+ */
+continue;
+}
 r = vhost_virtqueue_set_addr(dev, dev->vqs + i, idx,
  enable_log);
 if (r < 0) {
-- 
2.7.4