Re: [virtio-comment] [PATCH] block: Add multiqueue

From
Stefan Hajnoczi <>
Date
2019-09-18T10:24:34+00:00
ID
Thread
Re: [virtio-comment] [PATCH] block: Add multiqueue
On Tue, Sep 17, 2019 at 09:18:12AM +0200, Eugenio Pérez wrote:
> @@ -3973,6 +3984,11 @@ \subsection{Device Initialization}\label{sec:Device Types / Block Device / Devic
>      \field{max_write_zeroes_sectors} and \field{max_write_zeroes_seg} can
>      be read to determine the maximum write zeroes sectors and maximum
>      number of write zeroes segments for the block driver to use.
> +
> +\item If the VIRTIO_BLK_F_MQ feature is negotiated, \field{num_queues} field
> +    can be read to determine the number of queues. The driver does not use more
> +    queues than guest's number of CPUs.

Why state that "the driver does not use more queues than guest's number
of CPUs"?  This seems like an implementation detail and it's up to the
driver author to decide the most effective way of using multiqueue.