Messages in this thread | | | From | Jim Mattson <> | Date | Sat, 4 Nov 2023 05:08:13 -0700 | Subject | Re: [PATCH v6 01/20] KVM: x86/pmu: Don't allow exposing unsupported architectural events |
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On Fri, Nov 3, 2023 at 5:02 PM Sean Christopherson <seanjc@google.com> wrote: > > Hide architectural events that unsupported according to guest CPUID *or* > hardware, i.e. don't let userspace advertise and potentially program > unsupported architectural events.
The bitmask, pmu->available_event_types, is only used in intel_hw_event_available(). As discussed (https://lore.kernel.org/kvm/ZUU12-TUR_1cj47u@google.com/), intel_hw_event_available() should go away.
> Note, KVM already limits the length of the reverse polarity field, only > the mask itself is missing. > > Fixes: f5132b01386b ("KVM: Expose a version 2 architectural PMU to a guests") > Cc: stable@vger.kernel.org > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/x86/kvm/vmx/pmu_intel.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c > index 820d3e1f6b4f..1b13a472e3f2 100644 > --- a/arch/x86/kvm/vmx/pmu_intel.c > +++ b/arch/x86/kvm/vmx/pmu_intel.c > @@ -533,7 +533,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu) > pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << eax.split.bit_width) - 1; > eax.split.mask_length = min_t(int, eax.split.mask_length, > kvm_pmu_cap.events_mask_len); > - pmu->available_event_types = ~entry->ebx & > + pmu->available_event_types = ~(entry->ebx | kvm_pmu_cap.events_mask) & > ((1ull << eax.split.mask_length) - 1); > > if (pmu->version == 1) { > -- > 2.42.0.869.gea05f2083d-goog >
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