On Wed, Apr 24, 2019 at 07:17:23PM -0400, Krish Sadhukhan wrote:
> ...based on whether the guest CPU supports PMU
>
> Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
> Suggested-by: Jim Mattson <jmattson@xxxxxxxxxx>
> Reviewed-by: Karl Heubaum <karl.heubaum@xxxxxxxxxx>
> ---
> arch/x86/kvm/vmx/vmx.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index 4d39f731bc33..fa9c786afcfa 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -6964,6 +6964,7 @@ static void nested_vmx_cr_fixed1_bits_update(struct kvm_vcpu *vcpu)
> static void nested_vmx_entry_exit_ctls_update(struct kvm_vcpu *vcpu)
> {
> struct vcpu_vmx *vmx = to_vmx(vcpu);
> + bool pmu_enabled = guest_cpuid_has_pmu(vcpu);
A revert has been sent for the patch that added guest_cpuid_has_pmu().
Regardless, checking only the guest's CPUID 0xA is not sufficient, e.g.
at the bare minimum, exposing the controls can be done if and only if
cpu_has_load_perf_global_ctrl() is true.
In general, it's difficult for me to understand exactly what functionality
you intend to introduce. Proper changelogs would be very helpful.
>
> if (kvm_mpx_supported()) {
> bool mpx_enabled = guest_cpuid_has(vcpu, X86_FEATURE_MPX);
> @@ -6976,6 +6977,17 @@ static void nested_vmx_entry_exit_ctls_update(struct kvm_vcpu *vcpu)
> vmx->nested.msrs.exit_ctls_high &= ~VM_EXIT_CLEAR_BNDCFGS;
> }
> }
> + if (pmu_enabled) {
> + vmx->nested.msrs.entry_ctls_high |=
> + VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
> + vmx->nested.msrs.exit_ctls_high |=
> + VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL;
> + } else {
> + vmx->nested.msrs.entry_ctls_high &=
> + ~VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL;
> + vmx->nested.msrs.exit_ctls_high &=
> + ~VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL;
> + }
> }
>
> static void update_intel_pt_cfg(struct kvm_vcpu *vcpu)
> --
> 2.17.2
>
