Re: [PATCH v6 12/13] PCI: hv: Add hypercalls to read/write MMIO space

From: Lorenzo Pieralisi
Date: Fri Mar 24 2023 - 11:26:23 EST


On Fri, Mar 24, 2023 at 03:13:02PM +0000, Michael Kelley (LINUX) wrote:
> From: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx> Sent: Friday, March 24, 2023 7:48 AM
> >
> > On Wed, Mar 08, 2023 at 06:40:13PM -0800, Michael Kelley wrote:
> > > To support PCI pass-thru devices in Confidential VMs, Hyper-V
> > > has added hypercalls to read and write MMIO space. Add the
> > > appropriate definitions to hyperv-tlfs.h and implement
> > > functions to make the hypercalls.
> > >
> > > Co-developed-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
> > > Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
> > > Signed-off-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
> > > Reviewed-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> > > ---
> > > arch/x86/include/asm/hyperv-tlfs.h | 3 ++
> > > drivers/pci/controller/pci-hyperv.c | 64
> > +++++++++++++++++++++++++++++++++++++
> > > include/asm-generic/hyperv-tlfs.h | 22 +++++++++++++
> > > 3 files changed, 89 insertions(+)
> >
> > Nit: I'd squash this in with the patch where the calls are used,
> > don't think this patch is bisectable as it stands (maybe you
> > split them for review purposes, apologies if so).
> >
> > Lorenzo
>
> I did split the new code into two patches to make it more
> consumable from a review standpoint. But I'm not understanding
> what you mean by not being bisectable. After applying the first
> of the two patches, everything should still compile and work
> even though there are no users of the new hypercalls. Or maybe
> your concern is that there would be "unused function" warnings?

That's what I meant - that's it.

> In any case, squashing the two patches isn't a problem.

Thanks,
Lorenzo