* [PATCH] KVM: x86/pmu: Move Intel PMU global MSRs to intel_is_valid_msr()
@ 2026-09-02 18:47 Jim Mattson
2026-09-03 5:52 ` Sandipan Das
2026-09-03 6:57 ` Like Xu
0 siblings, 2 replies; 3+ messages in thread
From: Jim Mattson @ 2026-09-02 18:47 UTC (permalink / raw)
To: seanjc, pbonzini; +Cc: kvm, likexu, sandipan.das, yosry, Jim Mattson
Commit c85cdc1cc1ea ("KVM: x86/pmu: Move handling PERF_GLOBAL_CTRL and
friends to common x86") moved the existence check for the following Intel
PMU MSRs to kvm_pmu_is_valid_msr():
- MSR_CORE_PERF_GLOBAL_STATUS
- MSR_CORE_PERF_GLOBAL_CTRL
- MSR_CORE_PERF_GLOBAL_OVF_CTRL
That commit deemed these MSRs valid whenever pmu->version > 1. It intended
to share the check with AMD PerfMonV2 because both vendor implementations
require version 2 or greater for global PMU controls. However, as noted in
the commit message, AMD uses different MSR indices for its global PMU
registers.
Commit 4a2771895ca6 ("KVM: x86/svm/pmu: Add AMD PerfMonV2 support")
subsequently added AMD PerfMonV2 support and set pmu->version = 2. Because
kvm_pmu_is_valid_msr() validated the Intel MSRs whenever pmu->version > 1,
KVM incorrectly permitted AMD guests with PerfMonV2 to access these Intel
MSRs without a #GP.
Move the validation of these Intel MSRs to intel_is_valid_msr() and remove
the common switch statement from kvm_pmu_is_valid_msr(). AMD already
validates its own global PMU MSRs in amd_is_valid_msr().
Fixes: 4a2771895ca6 ("KVM: x86/svm/pmu: Add AMD PerfMonV2 support")
Signed-off-by: Jim Mattson <jmattson@google.com>
---
arch/x86/kvm/pmu.c | 8 --------
arch/x86/kvm/vmx/pmu_intel.c | 3 +++
2 files changed, 3 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index a7d60c8785cd..d2fd47ee5ec8 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -823,14 +823,6 @@ void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu)
bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
{
- switch (msr) {
- case MSR_CORE_PERF_GLOBAL_STATUS:
- case MSR_CORE_PERF_GLOBAL_CTRL:
- case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
- return kvm_pmu_has_perf_global_ctrl(vcpu_to_pmu(vcpu));
- default:
- break;
- }
return kvm_pmu_call(msr_idx_to_pmc)(vcpu, msr) ||
kvm_pmu_call(is_valid_msr)(vcpu, msr);
}
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index bfa8612fb450..70a8c4816135 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -187,6 +187,9 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
int ret;
switch (msr) {
+ case MSR_CORE_PERF_GLOBAL_STATUS:
+ case MSR_CORE_PERF_GLOBAL_CTRL:
+ case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
case MSR_CORE_PERF_FIXED_CTR_CTRL:
return kvm_pmu_has_perf_global_ctrl(pmu);
case MSR_IA32_PEBS_ENABLE:
--
2.55.0.970.g62bdec98f9-goog
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] KVM: x86/pmu: Move Intel PMU global MSRs to intel_is_valid_msr()
2026-09-02 18:47 [PATCH] KVM: x86/pmu: Move Intel PMU global MSRs to intel_is_valid_msr() Jim Mattson
@ 2026-09-03 5:52 ` Sandipan Das
2026-09-03 6:57 ` Like Xu
1 sibling, 0 replies; 3+ messages in thread
From: Sandipan Das @ 2026-09-03 5:52 UTC (permalink / raw)
To: Jim Mattson, seanjc, pbonzini; +Cc: kvm, likexu, yosry
On 03-09-2026 00:17, Jim Mattson wrote:
> Commit c85cdc1cc1ea ("KVM: x86/pmu: Move handling PERF_GLOBAL_CTRL and
> friends to common x86") moved the existence check for the following Intel
> PMU MSRs to kvm_pmu_is_valid_msr():
> - MSR_CORE_PERF_GLOBAL_STATUS
> - MSR_CORE_PERF_GLOBAL_CTRL
> - MSR_CORE_PERF_GLOBAL_OVF_CTRL
>
> That commit deemed these MSRs valid whenever pmu->version > 1. It intended
> to share the check with AMD PerfMonV2 because both vendor implementations
> require version 2 or greater for global PMU controls. However, as noted in
> the commit message, AMD uses different MSR indices for its global PMU
> registers.
>
> Commit 4a2771895ca6 ("KVM: x86/svm/pmu: Add AMD PerfMonV2 support")
> subsequently added AMD PerfMonV2 support and set pmu->version = 2. Because
> kvm_pmu_is_valid_msr() validated the Intel MSRs whenever pmu->version > 1,
> KVM incorrectly permitted AMD guests with PerfMonV2 to access these Intel
> MSRs without a #GP.
>
> Move the validation of these Intel MSRs to intel_is_valid_msr() and remove
> the common switch statement from kvm_pmu_is_valid_msr(). AMD already
> validates its own global PMU MSRs in amd_is_valid_msr().
>
> Fixes: 4a2771895ca6 ("KVM: x86/svm/pmu: Add AMD PerfMonV2 support")
> Signed-off-by: Jim Mattson <jmattson@google.com>
> ---
> arch/x86/kvm/pmu.c | 8 --------
> arch/x86/kvm/vmx/pmu_intel.c | 3 +++
> 2 files changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
> index a7d60c8785cd..d2fd47ee5ec8 100644
> --- a/arch/x86/kvm/pmu.c
> +++ b/arch/x86/kvm/pmu.c
> @@ -823,14 +823,6 @@ void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu)
>
> bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
> {
> - switch (msr) {
> - case MSR_CORE_PERF_GLOBAL_STATUS:
> - case MSR_CORE_PERF_GLOBAL_CTRL:
> - case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
> - return kvm_pmu_has_perf_global_ctrl(vcpu_to_pmu(vcpu));
> - default:
> - break;
> - }
> return kvm_pmu_call(msr_idx_to_pmc)(vcpu, msr) ||
> kvm_pmu_call(is_valid_msr)(vcpu, msr);
> }
> diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
> index bfa8612fb450..70a8c4816135 100644
> --- a/arch/x86/kvm/vmx/pmu_intel.c
> +++ b/arch/x86/kvm/vmx/pmu_intel.c
> @@ -187,6 +187,9 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
> int ret;
>
> switch (msr) {
> + case MSR_CORE_PERF_GLOBAL_STATUS:
> + case MSR_CORE_PERF_GLOBAL_CTRL:
> + case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
> case MSR_CORE_PERF_FIXED_CTR_CTRL:
> return kvm_pmu_has_perf_global_ctrl(pmu);
> case MSR_IA32_PEBS_ENABLE:
Reviewed-by: Sandipan Das <sandipan.das@amd.com>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] KVM: x86/pmu: Move Intel PMU global MSRs to intel_is_valid_msr()
2026-09-02 18:47 [PATCH] KVM: x86/pmu: Move Intel PMU global MSRs to intel_is_valid_msr() Jim Mattson
2026-09-03 5:52 ` Sandipan Das
@ 2026-09-03 6:57 ` Like Xu
1 sibling, 0 replies; 3+ messages in thread
From: Like Xu @ 2026-09-03 6:57 UTC (permalink / raw)
To: Jim Mattson, seanjc; +Cc: kvm, likexu, sandipan.das, yosry, pbonzini
On 9/3/26 2:47 AM, Jim Mattson wrote:
> Commit c85cdc1cc1ea ("KVM: x86/pmu: Move handling PERF_GLOBAL_CTRL and
> friends to common x86") moved the existence check for the following Intel
> PMU MSRs to kvm_pmu_is_valid_msr():
> - MSR_CORE_PERF_GLOBAL_STATUS
> - MSR_CORE_PERF_GLOBAL_CTRL
> - MSR_CORE_PERF_GLOBAL_OVF_CTRL
>
> That commit deemed these MSRs valid whenever pmu->version > 1. It intended
> to share the check with AMD PerfMonV2 because both vendor implementations
> require version 2 or greater for global PMU controls. However, as noted in
> the commit message, AMD uses different MSR indices for its global PMU
> registers.
>
> Commit 4a2771895ca6 ("KVM: x86/svm/pmu: Add AMD PerfMonV2 support")
> subsequently added AMD PerfMonV2 support and set pmu->version = 2. Because
> kvm_pmu_is_valid_msr() validated the Intel MSRs whenever pmu->version > 1,
> KVM incorrectly permitted AMD guests with PerfMonV2 to access these Intel
> MSRs without a #GP.
>
> Move the validation of these Intel MSRs to intel_is_valid_msr() and remove
> the common switch statement from kvm_pmu_is_valid_msr(). AMD already
> validates its own global PMU MSRs in amd_is_valid_msr().
>
> Fixes: 4a2771895ca6 ("KVM: x86/svm/pmu: Add AMD PerfMonV2 support")
> Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Like Xu <likexu@tencent.com>
> ---
> arch/x86/kvm/pmu.c | 8 --------
> arch/x86/kvm/vmx/pmu_intel.c | 3 +++
> 2 files changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
> index a7d60c8785cd..d2fd47ee5ec8 100644
> --- a/arch/x86/kvm/pmu.c
> +++ b/arch/x86/kvm/pmu.c
> @@ -823,14 +823,6 @@ void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu)
>
> bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
> {
> - switch (msr) {
> - case MSR_CORE_PERF_GLOBAL_STATUS:
> - case MSR_CORE_PERF_GLOBAL_CTRL:
> - case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
> - return kvm_pmu_has_perf_global_ctrl(vcpu_to_pmu(vcpu));
> - default:
> - break;
> - }
> return kvm_pmu_call(msr_idx_to_pmc)(vcpu, msr) ||
> kvm_pmu_call(is_valid_msr)(vcpu, msr);
> }
> diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
> index bfa8612fb450..70a8c4816135 100644
> --- a/arch/x86/kvm/vmx/pmu_intel.c
> +++ b/arch/x86/kvm/vmx/pmu_intel.c
> @@ -187,6 +187,9 @@ static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
> int ret;
>
> switch (msr) {
> + case MSR_CORE_PERF_GLOBAL_STATUS:
> + case MSR_CORE_PERF_GLOBAL_CTRL:
> + case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
> case MSR_CORE_PERF_FIXED_CTR_CTRL:
> return kvm_pmu_has_perf_global_ctrl(pmu);
> case MSR_IA32_PEBS_ENABLE:
^ permalink raw reply [flat|nested] 3+ messages in thread
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2026-09-02 18:47 [PATCH] KVM: x86/pmu: Move Intel PMU global MSRs to intel_is_valid_msr() Jim Mattson
2026-09-03 5:52 ` Sandipan Das
2026-09-03 6:57 ` Like Xu
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