Re: [PATCH v2 0/7] vfio-ccw parent rework

From: Eric Farman <farman@linux.ibm.com>
To: Matthew Rosato <mjrosato@linux.ibm.com>,
	Alex Williamson <alex.williamson@redhat.com>
Cc: Cornelia Huck <cohuck@redhat.com>,
	Jason Gunthorpe <jgg@nvidia.com>,
	Kevin Tian <kevin.tian@intel.com>, Yi Liu <yi.l.liu@intel.com>,
	Zhenyu Wang <zhenyuw@linux.intel.com>,
	Zhi Wang <zhi.a.wang@intel.com>,
	Jani Nikula <jani.nikula@linux.intel.com>,
	Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
	Rodrigo Vivi <rodrigo.vivi@intel.com>,
	Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
	David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
	Halil Pasic <pasic@linux.ibm.com>,
	Vineeth Vijayan <vneethv@linux.ibm.com>,
	Peter Oberparleiter <oberpar@linux.ibm.com>,
	Heiko Carstens <hca@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	Alexander Gordeev <agordeev@linux.ibm.com>,
	Christian Borntraeger <borntraeger@linux.ibm.com>,
	Sven Schnelle <svens@linux.ibm.com>,
	Tony Krowiak <akrowiak@linux.ibm.com>,
	Jason Herne <jjherne@linux.ibm.com>,
	Harald Freudenberger <freude@linux.ibm.com>,
	Diana Craciun <diana.craciun@oss.nxp.com>,
	Eric Auger <eric.auger@redhat.com>,
	Kirti Wankhede <kwankhede@nvidia.com>,
	Abhishek Sahu <abhsahu@nvidia.com>,
	Yishai Hadas <yishaih@nvidia.com>,
	intel-gvt-dev@lists.freedesktop.org,
	intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org,
	kvm@vger.kernel.org
Subject: Re: [PATCH v2 0/7] vfio-ccw parent rework
Date: Fri, 04 Nov 2022 08:23:37 -0400	[thread overview]
Message-ID: <611fd3a62596226e78af36909618ae65df615428.camel@linux.ibm.com> (raw)
In-Reply-To: <a408e8c7-6bd6-80de-5e59-815cb62fe29c@linux.ibm.com>

On Thu, 2022-11-03 at 19:43 -0400, Matthew Rosato wrote:
> On 11/3/22 5:56 PM, Alex Williamson wrote:
> > On Wed,  2 Nov 2022 16:01:45 +0100
> > Eric Farman <farman@linux.ibm.com> wrote:
> > 
> > > Hi all,
> > > 
> > > Here is an update to the vfio-ccw lifecycle changes that have
> > > been discussed
> > > in various forms over the past year [1][2] or so, and which I
> > > dusted off
> > > recently.
> > > 
> > > Patches 1-5 rework the behavior of the vfio-ccw driver's private
> > > struct.
> > > In summary, the mdev pieces are split out of vfio_ccw_private and
> > > into a
> > > new vfio_ccw_parent struct that will continue to follow today's
> > > lifecycle.
> > > The remainder (bulk) of the private struct moves to follow the
> > > mdev
> > > probe/remove pair. There's opportunity for further separation of
> > > the
> > > things in the private struct, which would simplify some of the
> > > vfio-ccw
> > > code, but it got too hairy as I started that. Once vfio-ccw is no
> > > longer
> > > considered unique, those cleanups can happen at our leisure. 
> > > 
> > > Patch 6 removes the trickery where vfio-ccw uses vfio_init_device
> > > instead of
> > > vfio_alloc_device, and thus removes vfio_init_device from the
> > > outside world.
> > > 
> > > Patch 7 removes vfio_free_device from vfio-ccw and the other
> > > drivers (hello,
> > > CC list!), letting it be handled by vfio_device_release directly.
> > 
> > Looks like another spin is pending, but the vfio core and
> > collateral
> > changes in 6 and 7 look good to me.  Would this go in through the
> > vfio
> > or s390 tree?  I'd be happy to merge or provide a branch, depending
> > on
> > the route.
> > 
> > For 6 & 7:
> > Acked-by: Alex Williamson <alex.williamson@redhat.com>
> > 
> > Thanks,
> > Alex
> 
> LGTM with those few comments addressed -- @Eric please send a v3 and
> I think it's ready.

Will do that now; thanks Matt.

> 
> I would suggest vfio tree to reduce the chance of conflicts; this
> touches various vfio drivers (and main) with the last patches while
> the s390 hits are at least all contained to the vfio-ccw driver code.
> 

Agreed. Thanks to you both.