Re: [PATCH v3 0/5] KVM: arm64: selftests: Fix get-reg-list

[Andrew Jones <drjones@redhat.com>]

On Mon, May 31, 2021 at 12:33:39PM +0200, Andrew Jones wrote:
> v3:
>  - Took Ricardo's suggestions in order to avoid needing to update
>    prepare_vcpu_init, finalize_vcpu, and check_supported when adding
>    new register sublists by better associating the sublists with their
>    vcpu feature bits and caps [Ricardo]
>  - We now dynamically generate the vcpu config name by creating them
>    from its sublist names [drew]
> 
> v2:
>  - Removed some cruft left over from a previous more complex design of the
>    config command line parser
>  - Dropped the list printing factor out patch as it's not necessary
>  - Added a 'PASS' output for passing tests to allow testers to feel good
>  - Changed the "up to date with kernel" comment to reference 5.13.0-rc2
> 
> 
> Since KVM commit 11663111cd49 ("KVM: arm64: Hide PMU registers from
> userspace when not available") the get-reg-list* tests have been
> failing with
> 
>   ...
>   ... There are 74 missing registers.
>   The following lines are missing registers:
>   ...
> 
> where the 74 missing registers are all PMU registers. This isn't a
> bug in KVM that the selftest found, even though it's true that a
> KVM userspace that wasn't setting the KVM_ARM_VCPU_PMU_V3 VCPU
> flag, but still expecting the PMU registers to be in the reg-list,
> would suddenly no longer have their expectations met. In that case,
> the expectations were wrong, though, so that KVM userspace needs to
> be fixed, and so does this selftest.
> 
> We could fix the test with a one-liner since we just need a
> 
>   init->features[0] |= 1 << KVM_ARM_VCPU_PMU_V3;
> 
> in prepare_vcpu_init(), but that's too easy, so here's a 5 patch patch
> series instead :-)  The reason for all the patches and the heavy diffstat
> is to prepare for other vcpu configuration testing, e.g. ptrauth and mte.
> With the refactoring done in this series, we should now be able to easily
> add register sublists and vcpu configs to the get-reg-list test, as the
> last patch demonstrates with the pmu fix.
> 
> Thanks,
> drew
> 
> 
> Andrew Jones (5):
>   KVM: arm64: selftests: get-reg-list: Introduce vcpu configs
>   KVM: arm64: selftests: get-reg-list: Prepare to run multiple configs
>     at once
>   KVM: arm64: selftests: get-reg-list: Provide config selection option
>   KVM: arm64: selftests: get-reg-list: Remove get-reg-list-sve
>   KVM: arm64: selftests: get-reg-list: Split base and pmu registers
> 
>  tools/testing/selftests/kvm/.gitignore        |   1 -
>  tools/testing/selftests/kvm/Makefile          |   1 -
>  .../selftests/kvm/aarch64/get-reg-list-sve.c  |   3 -
>  .../selftests/kvm/aarch64/get-reg-list.c      | 439 +++++++++++++-----
>  4 files changed, 321 insertions(+), 123 deletions(-)
>  delete mode 100644 tools/testing/selftests/kvm/aarch64/get-reg-list-sve.c
> 
> -- 
> 2.31.1
>

Gentle ping.

I'm not sure if I'm pinging Marc or Paolo though. MAINTAINERS shows Paolo
as all kvm selftests, but I think Marc has started picking up the AArch64
specific kvm selftests.

Marc, if you've decided to maintain AArch64 kvm selftests, would you be
opposed to adding

  F: tools/testing/selftests/kvm/*/aarch64/
  F: tools/testing/selftests/kvm/aarch64/

to "KERNEL VIRTUAL MACHINE FOR ARM64 (KVM/arm64)"?

Thanks,
drew