On 9/15/23 15:54, Tom Lendacky wrote:
> With the TSC_AUX virtualization support now in the vcpu_set_after_cpuid()
> path, the intercepts must be either cleared or set based on the guest
> CPUID input. Currently the support only clears the intercepts.
>
> Also, vcpu_set_after_cpuid() calls svm_recalc_instruction_intercepts() as
> part of the processing, so the setting or clearing of the RDTSCP intercept
> can be dropped from the TSC_AUX virtualization support.
>
> Update the support to always set or clear the TSC_AUX MSR intercept based
> on the virtualization requirements.
>
> Fixes: 296d5a17e793 ("KVM: SEV-ES: Use V_TSC_AUX if available instead of RDTSC/MSR_TSC_AUX intercepts")
> Signed-off-by: Tom Lendacky <[email protected]>
In the end, I was really on the fence about this being a separate patch
given the common Fixes: tag. Your call, feel free to squash with patch #1
and massage the commit message if you'd like (or I can send a v3 with them
squashed if you prefer).
Thanks,
Tom
> ---
> arch/x86/kvm/svm/sev.c | 11 +++++------
> 1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
> index 4ac01f338903..4900c078045a 100644
> --- a/arch/x86/kvm/svm/sev.c
> +++ b/arch/x86/kvm/svm/sev.c
> @@ -2966,12 +2966,11 @@ static void sev_es_vcpu_after_set_cpuid(struct vcpu_svm *svm)
> {
> struct kvm_vcpu *vcpu = &svm->vcpu;
>
> - if (boot_cpu_has(X86_FEATURE_V_TSC_AUX) &&
> - (guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) ||
> - guest_cpuid_has(vcpu, X86_FEATURE_RDPID))) {
> - set_msr_interception(vcpu, svm->msrpm, MSR_TSC_AUX, 1, 1);
> - if (guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP))
> - svm_clr_intercept(svm, INTERCEPT_RDTSCP);
> + if (boot_cpu_has(X86_FEATURE_V_TSC_AUX)) {
> + bool v_tsc_aux = guest_cpuid_has(vcpu, X86_FEATURE_RDTSCP) ||
> + guest_cpuid_has(vcpu, X86_FEATURE_RDPID);
> +
> + set_msr_interception(vcpu, svm->msrpm, MSR_TSC_AUX, v_tsc_aux, v_tsc_aux);
> }
> }
>