Re: [RFC PATCH v2 0/9] KVM: Enable Nested Virt selftests

[Ganapatrao Kulkarni]

[Sorry for late reply]

On 5/29/2025 5:18 PM, Marc Zyngier wrote:
> On Thu, 29 May 2025 11:29:58 +0100,
> Ganapatrao Kulkarni <gankulkarni@xxxxxxxxxxxxxxxxxxxxxx> wrote:
> > Hi Eric,
> >
> > On 5/28/2025 6:58 PM, Eric Auger wrote:
> > > Hi Ganapatrao,
> > >
> > > On 5/12/25 12:52 PM, Ganapatrao Kulkarni wrote:
> > > > This patch series makes the selftest work with NV enabled. The guest code
> > > > is run in vEL2 instead of EL1. We add a command line option to enable
> > > > testing of NV. The NV tests are disabled by default.
> > >
> > > For commodity, I would add in the coverletter that for all tests
> > > enhanced with vEL2 testing "-g 1" option shall be added to force that mode.
> >
> > Sure, will do.
> >
> > > I don't really get how you chose tests capable to run at vEL2 and
> > > excluded others? Wouldn't it make sense to have a way to run all tests
> > > in either mode?
> > There is no selection as such. I have worked on around 50% of the tests and sent for the early review.
> > Yes, almost all tests can/should run in vEL2 except few.
>
> Define EL2. You are so far assuming a E2H RES1 guest, and I don't see
> anything that is even trying E2H RES0. After all the complaining that

Sure, I will mention that default test code runs in EL2 with E2H enabled.
The tests code is in vEL2 with E2H RES1 by default, since host is booted with VHE.

> E2H0 wasn't initially supported, this is a bit... disappointing.
IIRC, I was mentioning about L1 switching between arch mmu table and guest mmu table(VMID 0).
I don't remember why It was switching.
 > 
> Also, running EL2 is the least of our worries, because that's pretty
> easy to deal with. It is running at EL1/0 when EL2 is present that is
> interesting, and I see no coverage on that front.

Sorry, I did not get this comment fully.
When we run selftest on Host with -g option, the guest code will run in vEL2 as L1.
This is implemented as per comment in V1.

When we run same selftest from L1 shell, then guest_code will be running in EL0/1 like running from L0.

--
Thanks,
Gk