RE: [PATCH v2 00/94] KVM: arm64: ARMv8.3/8.4 Nested Virtualization support

From: "Zengtao (B)" <prime.zeng@hisilicon.com>
To: Marc Zyngier <maz@kernel.org>
Cc: George Cherian <gcherian@marvell.com>,
	"Dave.Martin@arm.com" <Dave.Martin@arm.com>,
	"alexandru.elisei@arm.com" <alexandru.elisei@arm.com>,
	"andre.przywara@arm.com" <andre.przywara@arm.com>,
	"christoffer.dall@arm.com" <christoffer.dall@arm.com>,
	"james.morse@arm.com" <james.morse@arm.com>,
	"jintack@cs.columbia.edu" <jintack@cs.columbia.edu>,
	"julien.thierry.kdev@gmail.com" <julien.thierry.kdev@gmail.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"suzuki.poulose@arm.com" <suzuki.poulose@arm.com>,
	Anil Kumar Reddy H <areddy3@marvell.com>,
	Ganapatrao Kulkarni <gkulkarni@marvell.com>
Subject: RE: [PATCH v2 00/94] KVM: arm64: ARMv8.3/8.4 Nested Virtualization support
Date: Sat, 18 Apr 2020 02:49:23 +0000	[thread overview]
Message-ID: <678F3D1BB717D949B966B68EAEB446ED3A545C71@dggemm526-mbx.china.huawei.com> (raw)
In-Reply-To: <20200417160602.26706917@why>

 -----Original Message-----
> From: Marc Zyngier [mailto:maz@kernel.org]
> Sent: Friday, April 17, 2020 11:06 PM
> To: Zengtao (B)
> Cc: George Cherian; Dave.Martin@arm.com; alexandru.elisei@arm.com;
> andre.przywara@arm.com; christoffer.dall@arm.com;
> james.morse@arm.com; jintack@cs.columbia.edu;
> julien.thierry.kdev@gmail.com; kvm@vger.kernel.org;
> kvmarm@lists.cs.columbia.edu; linux-arm-kernel@lists.infradead.org;
> suzuki.poulose@arm.com; Anil Kumar Reddy H; Ganapatrao Kulkarni
> Subject: Re: [PATCH v2 00/94] KVM: arm64: ARMv8.3/8.4 Nested
> Virtualization support
> 
> On Thu, 16 Apr 2020 19:22:21 +0100
> Marc Zyngier <maz@kernel.org> wrote:
> 
> > Hi Zengtao,
> >
> > On 2020-04-16 02:38, Zengtao (B) wrote:
> > > Hi Marc:
> > >
> > > Got it.
> > > Really a bit patch set :)
> >
> > Well, yeah... ;-)
> >
> > >
> > > BTW, I have done a basic kvm unit test
> > > git://git.kernel.org/pub/scm/virt/kvm/kvm-unit-tests.git
> > > And I find that after apply the patch KVM: arm64: VNCR-ize ELR_EL1,
> > > The psci test failed for some reason, I can't understand why, this
> > > is only the test result.(find the patch by git bisect + kvm test)
> >
> > That it is that mechanical, we should be able to quickly nail that one.
> >
> > > My platform: Hisilicon D06 board.
> > > Linux kernel: Linux 5.6-rc6 + nv patches(some rebases)
> > > Could you help to take a look?
> >
> > I'll have a look tomorrow. I'm in the middle of refactoring the series
> > for 5.7, and things have changed quite a bit. Hopefully this isn't a VHE
> > vs non-VHE issue.
> 
> So I've repeatedly tried with the current state of the NV patches[1],
> on both an ARMv8.0 system (Seattle) and an ARMv8.2 pile of putrid junk
> (vim3l). PSCI is pretty happy, although I can only test with at most 8
> vcpus (GICv2 gets in the way).
> 
> Can you please:
> 
> - post the detailed error by running the PSCI unit test on its own
I tried to trace the error, and I found in kernel function kvm_mpidr_to_vcpu,
casually, mpidr returns zero and we can't get the expected vcpu, and psci
 test failed due to this.
And as I mentioned in my last before, the psci error is introduced by the
 patch KVM: arm64: VNCR-ize ELR_EL1.(Only test result)
Maybe you have to try tens of times to reproduce. :)
Deep into the patch itself, I don't find any connection between the patch
and the issue.

> - test with the current state of the patches
I test with your nv-5.7-rc1-WIP branch and latest kvm_unit_test, the 
error still exist.

Thanks.
zengtao

> 

> Thanks,
> 
> 	M.
> 
> [1]
> https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/l
> og/?h=kvm-arm64/nv-5.7-rc1-WIP
> --
> Jazz is not dead. It just smells funny...