Re: [PATCH v5 8/8] selftests: KVM: x86: Add SEV PML dirty logging test

["Nikunj A. Dadhania" <nikunj@amd.com>]

On 1/14/2026 5:06 PM, Huang, Kai wrote:
> On Mon, 2026-01-05 at 06:36 +0000, Nikunj A Dadhania wrote:
>> Add a KVM selftest to verify Page Modification Logging (PML) functionality
>> with AMD SEV/SEV-ES/SEV-SNP guests. The test validates that
>> hardware-assisted dirty page tracking works correctly across different SEV
>> guest types.
> 
> Hi Nikunj,
> 
> Perhaps a dumb question -- Why do we need specific selftest case for SEV*
> guests?

As there was a request from you to check if SEV supports PML,
I wrote this test and thought to send it as part of this series.

> In terms of GPA logging, my understanding is there's no difference between
> normal AMD SVM guests and SEV* guests from hardware's point of view.  So
> if PML works for normal AMD SVM guests, it should work for SEV* guests,
> no?

Yes, that is correct.

> 
> FWIW, a more reasonable selftest case is we probably need a AMD version of
> vmx_dirty_log_test.c[*], which verifies PML is indeed not enabled when L2
> runs.

Yosry has added the support here [1].

> 
> [*]: see commit 094444204570 ("selftests: kvm: add test for dirty logging
> inside nested guests").

Regards
Nikunj

1. https://lore.kernel.org/kvm/20251230230150.4150236-19-seanjc@google.com/