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 <stefa...@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com> --- 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