Re: [PATCH v3 2/3] vhost: Use vhost_get_used_size() in vhost_vring_set_addr()

[Jason Wang]

On 2020/10/3 下午6:02, Greg Kurz wrote:
> The open-coded computation of the used size doesn't take the event
> into account when the VIRTIO_RING_F_EVENT_IDX feature is present.
> Fix that by using vhost_get_used_size().
>
> Signed-off-by: Greg Kurz <groug@xxxxxxxx>
> ---
>   drivers/vhost/vhost.c |    3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index c3b49975dc28..9d2c225fb518 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -1519,8 +1519,7 @@ static long vhost_vring_set_addr(struct vhost_dev *d,
>   		/* Also validate log access for used ring if enabled. */
>   		if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) &&
>   			!log_access_ok(vq->log_base, a.log_guest_addr,
> -				sizeof *vq->used +
> -				vq->num * sizeof *vq->used->ring))
> +				       vhost_get_used_size(vq, vq->num)))
>   			return -EINVAL;
>   	}
>   

Acked-by: Jason Wang <jasowang@xxxxxxxxxx>