[PATCH] vhost: fix vring addr update with vDPA

[Maxime Coquelin]

On 3/7/24 11:34, David Marchand wrote:
> For vDPA devices, vq are not locked once the device has been configured
> at runtime.
> 
> On the other hand, we need to hold the vq lock to evaluate vq->access_ok,
> invalidate vring addresses and translate them.
> 
> Move vring address update earlier and, when vDPA is configured, skip parts
> which expect lock to be taken.
> 
> Bugzilla ID: 1394
> Fixes: 741dc052eaf9 ("vhost: annotate virtqueue access checks")
> 
> Signed-off-by: David Marchand <david.marchand at redhat.com>
> ---
> No change, just resending for CI.
> 
> ---
>   lib/vhost/vhost_user.c | 14 +++++++++-----
>   1 file changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
> index 3aba32c95a..7fe1687f08 100644
> --- a/lib/vhost/vhost_user.c
> +++ b/lib/vhost/vhost_user.c
> @@ -986,17 +986,20 @@ vhost_user_set_vring_addr(struct virtio_net **pdev,
>   	/* addr->index refers to the queue index. The txq 1, rxq is 0. */
>   	vq = dev->virtqueue[ctx->msg.payload.addr.index];
>   
> -	/* vhost_user_lock_all_queue_pairs locked all qps */
> -	VHOST_USER_ASSERT_LOCK(dev, vq, VHOST_USER_SET_VRING_ADDR);
> -
> -	access_ok = vq->access_ok;
> -
>   	/*
>   	 * Rings addresses should not be interpreted as long as the ring is not
>   	 * started and enabled
>   	 */
>   	memcpy(&vq->ring_addrs, addr, sizeof(*addr));
>   
> +	if (dev->flags & VIRTIO_DEV_VDPA_CONFIGURED)
> +		goto out;
> +
> +	/* vhost_user_lock_all_queue_pairs locked all qps */
> +	VHOST_USER_ASSERT_LOCK(dev, vq, VHOST_USER_SET_VRING_ADDR);
> +
> +	access_ok = vq->access_ok;
> +
>   	vring_invalidate(dev, vq);
>   
>   	if ((vq->enabled && (dev->features &
> @@ -1006,6 +1009,7 @@ vhost_user_set_vring_addr(struct virtio_net **pdev,
>   		*pdev = dev;
>   	}
>   
> +out:
>   	return RTE_VHOST_MSG_RESULT_OK;
>   }
>   

Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>

Thanks,
Maxime