RE: [PATCH v8 07/10] hyper-v: globalize vp_index

From: Jork Loeser
Date: Wed Jun 14 2017 - 00:31:44 EST


> From: Vitaly Kuznetsov [mailto:vkuznets@xxxxxxxxxx]
> Sent: Tuesday, June 13, 2017 19:29
>
> Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx> writes:
>
> > On Fri, 9 Jun 2017 15:27:33 +0200
> > Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> wrote:
> >
> >> To support implementing remote TLB flushing on Hyper-V with a
> >> hypercall we need to make vp_index available outside of vmbus module.
> >> Rename and globalize.
> >>
> >> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> >> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> >
> > This is correct, but needs to be rebased.
> > It conflicts with the PCI protocol version 1.2 patches that are in the
> > PCI tree.
>
> :-(
>
> The question is - what do we do? As far as I understand the intent was to push
> this through Greg's char-misc tree. If I rebase it to Bjorn's pci tree patches won't
> apply to char-misc and Greg won't take them. I see three possible ways to go:
> 1) Take them into char-misc and resolve the conflict in merge window (Linus will
> hate us all :-( )
> 2) Ask Greg to merge with Bjorn _now_ so we can send the rebased version.
> 3) Postpone these patches to the next kernel release. No guarantee we won't
> clash with something else :-(
>
> So I'm a bit lost. With Hyper-V drivers scattered across multiple trees we're
> doomed to have such issues with every relatively big series.

I would like to see Vitaly's patch-set being integrated shortly (option 1).

In anticipation of this, the PCI protocol version 1.2 patches duplicate the CPU-ID/vCPU-ID mapping. The conflict thus is "just" a re-naming conflict - taking either old or new is fine (one occurrence of conflict). Is this acceptable for conflict management without instilling undue despise?

That said, I am more than happy to help in the resolution. Also, once both changes are merged, I'll remove the duplicated logic.

Regards,
Jork