RE: [PATCH v5 0/9] Enhance the hv_vmbus driver to support hibernation

[Dexuan Cui]

> From: Sasha Levin <sashal@xxxxxxxxxx>
> Sent: Sunday, September 8, 2019 5:13 AM
> On Fri, Sep 06, 2019 at 10:45:31PM +0000, Dexuan Cui wrote:
> >> From: Sasha Levin <sashal@xxxxxxxxxx>
> >> Sent: Friday, September 6, 2019 1:03 PM
> >> On Thu, Sep 05, 2019 at 11:01:14PM +0000, Dexuan Cui wrote:
> >> >This patchset (consisting of 9 patches) was part of the v4 patchset
> (consisting
> >> >of 12 patches):
> >> >
> >> >The other 3 patches in v4 are posted in another patchset, which will go
> >> >through the tip.git tree.
> >> >
> >> >All the 9 patches here are now rebased to the hyperv tree's hyperv-next
> >> branch, and all the 9 patches have Michael Kelley's Signed-off-by's.
> >> >
> >> >Please review.
> >>
> >> Given that these two series depend on each other, I'd much prefer for
> >> them to go through one tree.
> >
> >Hi Sasha,
> >Yeah, that would be ideal. The problem here is: the other patchset conflicts
> >with the existing patches in the tip.git tree's timers/core branch, so IMO
> >the 3 patches have to go through the tip tree:
> >
> >[PATCH v5 1/3] x86/hyper-v: Suspend/resume the hypercall page for
> hibernation
> >[PATCH v5 2/3] x86/hyper-v: Implement hv_is_hibernation_supported()
> >[PATCH v5 3/3] clocksource/drivers: Suspend/resume Hyper-V clocksource for
> hibernation
> >
> >> But, I may be wrong, and I'm going to see if a scenario such as this
> >> make sense. I've queued this one to the hyperv-next, but I'll wait for
> >> the x86 folks to send their pull request to Linus first before I do it
> >> for these patches.
> >
> >Actually IMHO you don't need to wait, because there is not a build
> >dependency, so either patchset can go into the Linus's tree first.
> 
> It'll build, sure. But did anyone actually test one without the other?

Nobody tested this.

The fact is: even if we have the 2 patchsets, hibernation still can not work
for Linux VM on Hyper-V, because we also need the high level driver
changes to hv_netvsc, hv_storvsc, etc. I'm going to send out these
patches soon.

> What happens if Thomas doesn't send his batch at all during the merge
> window?
> Sasha

We need all the patches together to make hibernation work.
I just meant that the 2 patchsets don't have to go into Linus's tree in
a special order, as there is no build issue. 

Thanks,
-- Dexuan