Re: [PATCH v2 13/49] KVM: selftests: Fix a bad TEST_REQUIRE() in x86's KVM PV test

From: Maxim Levitsky
Date: Thu Jul 04 2024 - 21:17:49 EST


On Fri, 2024-05-17 at 10:38 -0700, Sean Christopherson wrote:
> Actually check for KVM support for disabling HLT-exiting instead of
> effectively checking that KVM_CAP_X86_DISABLE_EXITS is #defined to a
> non-zero value, and convert the TEST_REQUIRE() to a simple return so
> that only the sub-test is skipped if HLT-exiting is mandatory.
>
> The goof has likely gone unnoticed because all x86 CPUs support disabling
> HLT-exiting, only systems with the opt-in mitigate_smt_rsb KVM module
> param disallow HLT-exiting.
>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/x86_64/kvm_pv_test.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c b/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c
> index 78878b3a2725..2aee93108a54 100644
> --- a/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c
> +++ b/tools/testing/selftests/kvm/x86_64/kvm_pv_test.c
> @@ -140,10 +140,11 @@ static void test_pv_unhalt(void)
> struct kvm_cpuid_entry2 *ent;
> u32 kvm_sig_old;
>
> + if (!(kvm_check_cap(KVM_CAP_X86_DISABLE_EXITS) & KVM_X86_DISABLE_EXITS_HLT))
> + return;
> +
> pr_info("testing KVM_FEATURE_PV_UNHALT\n");
>
> - TEST_REQUIRE(KVM_CAP_X86_DISABLE_EXITS);
> -
> /* KVM_PV_UNHALT test */
> vm = vm_create_with_one_vcpu(&vcpu, guest_main);
> vcpu_set_cpuid_feature(vcpu, X86_FEATURE_KVM_PV_UNHALT);

Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>

Best regards,
Maxim Levitsky