Re: [PATCH v2 0/2] virtio-pmem: Support PCI BAR-relative addresses

From: Dan Williams <dan.j.williams@intel.com>
To: Taylor Stark <tstark@linux.microsoft.com>
Cc: Vishal L Verma <vishal.l.verma@intel.com>,
	Dave Jiang <dave.jiang@intel.com>,
	 "Weiny, Ira" <ira.weiny@intel.com>,
	Linux NVDIMM <nvdimm@lists.linux.dev>,
	apais@microsoft.com,  tyhicks@microsoft.com,
	jamorris@microsoft.com, benhill@microsoft.com,
	 sunilmut@microsoft.com, grahamwo@microsoft.com,
	tstark@microsoft.com
Subject: Re: [PATCH v2 0/2] virtio-pmem: Support PCI BAR-relative addresses
Date: Wed, 25 Aug 2021 15:05:16 -0700	[thread overview]
Message-ID: <CAPcyv4i0PYOJthSs0UmgOAXSVZ0ggQNnS86ViLKVfCz8Bv0dgQ@mail.gmail.com> (raw)
In-Reply-To: <20210825215622.GB3868@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net>

On Wed, Aug 25, 2021 at 2:56 PM Taylor Stark <tstark@linux.microsoft.com> wrote:
>
> On Tue, Aug 24, 2021 at 05:35:48PM -0700, Dan Williams wrote:
> > On Thu, Jul 15, 2021 at 3:34 PM Taylor Stark <tstark@linux.microsoft.com> wrote:
> > >
> > > Changes from v1 [1]:
> > >  - Fixed a bug where the guest might touch pmem region prior to the
> > >    backing file being mapped into the guest's address space.
> > >
> > > [1]: https://www.mail-archive.com/linux-nvdimm@lists.01.org/msg23736.html
> > >
> > > ---
> > >
> > > These patches add support to virtio-pmem to allow the pmem region to be
> > > specified in either guest absolute terms or as a PCI BAR-relative address.
> > > This is required to support virtio-pmem in Hyper-V, since Hyper-V only
> > > allows PCI devices to operate on PCI memory ranges defined via BARs.
> > >
> > > Taylor Stark (2):
> > >   virtio-pmem: Support PCI BAR-relative addresses
> > >   virtio-pmem: Set DRIVER_OK status prior to creating pmem region
> >
> > Are these patches still valid? I am only seeing one of them on the list.
>
> I'd hold off on taking a look for now. I'll need to post a v3 based on some
> suggestions while I was updating the virtio-pmem spec. It's a small change
> compared to the current patches (adds in a feature bit check). I'll post v3
> when the virtio-pmem base spec goes in. More info here:
>
> https://lists.oasis-open.org/archives/virtio-comment/202107/msg00169.html
>
> And yes, I messed up how I sent the patches. First time making linux changes,
> so I had some bumps while getting my email properly configured.. :)

No worries, yes it's a pain. It turns out Konstantin is trying to make
that process easier for new contributors:

https://lore.kernel.org/workflows/20210616171813.bwvu6mtl4ltotf7p@nitro.local/

...but I don't think that's up and running yet.