Re: [PULL] GVT-g device model core

Daniel Vetter
2016-10-17T07:33:23Z

On Mon, Oct 17, 2016 at 09:30:45AM +0200, Daniel Vetter wrote:
> On Fri, Oct 14, 2016 at 06:30:30PM +0800, Zhenyu Wang wrote:
> >
> > Hi,
> >
> > This is first pull request to merge GVT-g device model in i915
> > which contains core GVT-g device model work to virtualize GPU
> > resources. This tries to add feature of Intel GVT-g technology
> > for full GPU virtualization. This version will support KVM based
> > virtualization solution named as KVMGT.
> >
> > More background is on official project home: https://01.org/igvt-g
> >
> > To manage mediated device between virtual GPU and physical device it
> > will rely on VFIO/mdev framework, this version has not included GVT-g
> > device model integration work for VFIO/mdev yet as VFIO community is
> > still under work to refine code base. Currently we're basing on
> > VFIO/mdev v8 patch series (http://www.spinics.net/lists/kvm/msg138515.html)
> > and doing more testings on that.
> >
> > There're also several KVM change dependences. KVM maintainer has
> > merged two and we will ensure left hits KVM tree before sending new
> > pull request to enable that.
> >
> > p.s, There would require some coordinate work for VFIO/mdev. We will
> > send device model work for that after Alex merged mdev framework in
> > VFIO tree. Alex has promised to merge that in early of Nov.
> >
> > Let me know if there's any issue with this our first pull request.
>
> Ok applied, but a few things to keep in mind before your next pull
> request:
>
> - Dont rebase everything 5 seconds before sending out the pull request.
> That just invalidates all the testing you've done, so not a good idea.
> In general try to avoid rebases as much as possible, and only rebase to
> take out a truly embarassing mistake. And then only rebase up to the
> patch that needs a hotfix, not your entire tree.
>
> - Similar, don't base your pull requests upon a random commit of the day
> (that's why I noticed you rebased). Instead pick something meaningful,
> like a tag I (or Dave Airlie or Linus Torvalds) push out. Or another
> good option is to base it right on top of the last merge commit from
> gvt. Once you've picked a baseline, don't change it (except when you
> have a good reason). And if you need a patch from upstream also don't
> rebase, just send out a pull request with your current patch pile, and
> then continue applying more stuff on top once I merged that.
>
> - One technical nit on the integration: My idea was that i915 core code
> only calls a few specific functions and structures exposed through
> intel_gvt.h. But that file now seems to include gvt-internal headers,
> which is a bit a mess. Please clean that up in the next pull request:
>
> * Anything that core i915 code or headers needs must be moved into
> intel_gvt.h.
> * Everything else, including the 2 gvt includes we now have (gvt/gvt.h
> and i915_pvinfo.h) should only be included from code in
> drm/i915/gvt.h. So either sprinkle include directives over your source
> files for everything, or make gvt/gvt.h the main gvt header that pulls
> in everything.
>
> The idea here is similar to drm core vs. i915: drm core headers never
> pull in i915 headers, and all communication happens through the
> well-defined interfaces in drm core header files. I think our goal with
> gvt should be similar, with all the interfaces being in intel_gvt.h.
> Otherwise I fear the submaintainer model will be a bit painful, if we
> don't aim for strict separation here.
>
> - There's not yet a MAINTAINERS entry for i915/gvt with gvt mailing lists,
> git repos and your name on it. Please fix that in the next pull request,
> too.
>
> - gvt seems to lack kernel-doc entirely. I think we need at least an
> overview file and interface documentation for the stuff in
> intel_gvt.[hc]. Please run
>
> $ make hmtldocs
>
> to make sure it all looks pretty (you need to add stanzas in
> Documenation/gpu/i915.rst to include things). Another item for the next
> pull request please.

Quick addition: Since this will be a patch touching i915 core code pls
submit it to intel-gfx for review. You can then apply it to your tree once
it's reviewed (or Joonas or someone can commit directly to
drm-intel-next-queued).

And another item:
- Please add me to the moderation whitelist of igt-g-dev, I don't want to
be spammed by moderation mails every time I reply to your pull requests
;-)

Cheers, Daniel

>
> Also, this is the first time ever I've taken a pull request, so some
> learning involved on my side too. Please bear with me ;-)
>
> Cheers, Daniel
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch

--
Daniel Vetter
Software Engineer, Intel Corporation