Re: [PATCH] virtio-blk: support polling I/O

[Suwan Kim <suwan.kim027@gmail.com>]

On Fri, Mar 11, 2022 at 10:38:07AM -0500, Michael S. Tsirkin wrote:
> On Sat, Mar 12, 2022 at 12:28:32AM +0900, Suwan Kim wrote:
> > diff --git a/include/uapi/linux/virtio_blk.h b/include/uapi/linux/virtio_blk.h
> > index d888f013d9ff..3fcaf937afe1 100644
> > --- a/include/uapi/linux/virtio_blk.h
> > +++ b/include/uapi/linux/virtio_blk.h
> > @@ -119,8 +119,9 @@ struct virtio_blk_config {
> >  	 * deallocation of one or more of the sectors.
> >  	 */
> >  	__u8 write_zeroes_may_unmap;
> > +	__u8 unused1;
> >  
> > -	__u8 unused1[3];
> > +	__virtio16 num_poll_queues;
> >  } __attribute__((packed));
> 
> Same as any virtio UAPI change, this has to go through the virtio TC.
> In particular I don't think gating a new config field on
> an existing feature flag is a good idea.

Did you mean that the polling should be based on a new feature like
"VIRTIO_BLK_F_POLL" and be added at the end of features_legacy[]
and features[]? If then, I will add the new feture flag and resend it.

Regards,
Suwan Kim