Re: [PATCH] KVM: selftests: hyperv_features: test write of 1 to HV_X64_MSR_RESET

From: Vitaly Kuznetsov

Date: Mon May 25 2026 - 08:27:51 EST


Piotr Zarycki <piotr.zarycki@xxxxxxxxx> writes:

> Hi,
>
> After receiving KVM_SYSTEM_EVENT_RESET the test simply advances to the
> next stage without resetting the vCPU. Is verifying
> KVM_SYSTEM_EVENT_RESET is delivered sufficient?
>

For every stage of this test we're basically using a new VM
(vm_create_with_one_vcpu()) thus it does not really matter much what we
do after receiving KVM_SYSTEM_EVENT_RESET.

The basic idea behind the test was to verify that
KVM_CAP_HYPERV_ENFORCE_CPUID works as expected, i.e. the guest gets
access to the MSRs/hypercalls according to the guest visible CPUIDs and
not to everything KVM knows about (I guess we could've named it
'hyperv_feature_access' to actually reflect that). It, however, makes
sense to actually test side-effects of writing to MSRs/using hypercalls,
especially when it's relatively easy and I see that the change here goes
in this direction. With this, I think it is a good and sufficient
change, so

Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

Thanks!

--
Vitaly