Re: [Qemu-devel] [PATCH 4/4] docs: avoid vhost-user-net specifics in multiqueue section

[Marc-André Lureau]

On Fri, Jun 21, 2019 at 11:41 AM Stefan Hajnoczi <address@hidden> wrote:
>
> The "Multiple queue support" section makes references to vhost-user-net
> "queue pairs".  This is confusing for two reasons:
> 1. This actually applies to all device types, not just vhost-user-net.
> 2. VHOST_USER_GET_QUEUE_NUM returns the number of virtqueues, not the
>    number of queue pairs.
>
> Reword the section so that the vhost-user-net specific part is relegated
> to the very end: we acknowledge that vhost-user-net historically
> automatically enabled the first queue pair.
>
> Signed-off-by: Stefan Hajnoczi <address@hidden>

Reviewed-by: Marc-André Lureau <address@hidden>

> ---
>  docs/interop/vhost-user.rst | 21 +++++++++++----------
>  1 file changed, 11 insertions(+), 10 deletions(-)
>
> diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst
> index dc0ff9211f..5750668aba 100644
> --- a/docs/interop/vhost-user.rst
> +++ b/docs/interop/vhost-user.rst
> @@ -324,19 +324,20 @@ must support changing some configuration aspects on the 
> fly.
>  Multiple queue support
>  ----------------------
>
> -Multiple queue is treated as a protocol extension, hence the slave has
> -to implement protocol features first. The multiple queues feature is
> -supported only when the protocol feature ``VHOST_USER_PROTOCOL_F_MQ``
> -(bit 0) is set.
> +Multiple queue support allows the slave to advertise the maximum number of
> +queues.  This is treated as a protocol extension, hence the slave has to
> +implement protocol features first. The multiple queues feature is supported
> +only when the protocol feature ``VHOST_USER_PROTOCOL_F_MQ`` (bit 0) is set.
>
> -The max number of queue pairs the slave supports can be queried with
> -message ``VHOST_USER_GET_QUEUE_NUM``. Master should stop when the
> -number of requested queues is bigger than that.
> +The max number of queues the slave supports can be queried with message
> +``VHOST_USER_GET_QUEUE_NUM``. Master should stop when the number of requested
> +queues is bigger than that.
>
>  As all queues share one connection, the master uses a unique index for each
> -queue in the sent message to identify a specified queue. One queue pair
> -is enabled initially. More queues are enabled dynamically, by sending
> -message ``VHOST_USER_SET_VRING_ENABLE``.
> +queue in the sent message to identify a specified queue.
> +
> +The master enables queues by sending message ``VHOST_USER_SET_VRING_ENABLE``.
> +vhost-user-net has historically automatically enabled the first queue pair.
>
>  Migration
>  ---------
> --
> 2.21.0
>