Re: [PATCH v6 00/20] Add VFIO mediated device support and DEV-MSI support for the idxd driver

Jason Gunthorpe
2021-06-03T11:23:53Z

On Thu, Jun 03, 2021 at 05:52:58AM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <jgg@nvidia.com>
> > Sent: Thursday, June 3, 2021 9:50 AM
> >
> > On Thu, Jun 03, 2021 at 01:11:37AM +0000, Tian, Kevin wrote:
> >
> > > Jason, can you clarify your attitude on mdev guid stuff? Are you
> > > completely against it or case-by-case? If the former, this is a big
> > > decision thus it's better to have consensus with Alex/Kirti. If the
> > > latter, would like to hear your criteria for when it can be used
> > > and when not...
> >
> > I dislike it generally, but it exists so <shrug>. I know others feel
> > more strongly about it being un-kernely and the wrong way to use sysfs.
> >
> > Here I was remarking how the example in the cover letter made the mdev
> > part seem totally pointless. If it is pointless then don't do it.
>
> Is your point about that as long as a mdev requires pre-config
> through driver specific sysfs then it doesn't make sense to use
> mdev guid interface anymore?

Yes

> The value of mdev guid interface is providing a vendor-agnostic
> interface for mdev life-cycle management which allows one-
> enable-fit-all in upper management stack. Requiring vendor
> specific pre-config does blur the boundary here.

It isn't even vendor-agnostic - understanding the mdev_type
configuration stuff is still vendor specific.

Jason