linux-kernel - [PATCH] KVM: x86/pmu: Rename global_ovf_ctrl_mask to global_status

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Message-ID: <20230602221236.952888-1-seanjc@google.com>
Date:   Fri,  2 Jun 2023 15:12:36 -0700
From:   Sean Christopherson <seanjc@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Like Xu <like.xu.linux@...il.com>
Subject: [PATCH] KVM: x86/pmu: Rename global_ovf_ctrl_mask to global_status_mask

Rename global_ovf_ctrl_mask to global_status_mask to avoid confusion now
that Intel has renamed GLOBAL_OVF_CTRL to GLOBAL_STATUS_RESET in PMU v4.
GLOBAL_OVF_CTRL and GLOBAL_STATUS_RESET are the same MSR index, i.e. are
just different names for the same thing, but the SDM provides different
entries in the IA-32 Architectural MSRs table, which gets really confusing
when looking at PMU v4 definitions since it *looks* like GLOBAL_STATUS has
bits that don't exist in GLOBAL_OVF_CTRL, but in reality the bits are
simply defined in the GLOBAL_STATUS_RESET entry.

No functional change intended.

Cc: Like Xu <like.xu.linux@...il.com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 arch/x86/include/asm/kvm_host.h |  2 +-
 arch/x86/kvm/vmx/pmu_intel.c    | 18 ++++++++++++++----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index fb9d1f2d6136..28bd38303d70 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -523,7 +523,7 @@ struct kvm_pmu {
 	u64 global_status;
 	u64 counter_bitmask[2];
 	u64 global_ctrl_mask;
-	u64 global_ovf_ctrl_mask;
+	u64 global_status_mask;
 	u64 reserved_bits;
 	u64 raw_event_mask;
 	struct kvm_pmc gp_counters[KVM_INTEL_PMC_MAX_GENERIC];
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 741efe2c497b..fb96cbfc9ae8 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -427,7 +427,11 @@ static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		}
 		break;
 	case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
-		if (data & pmu->global_ovf_ctrl_mask)
+		/*
+		 * GLOBAL_OVF_CTRL, a.k.a. GLOBAL STATUS_RESET, clears bits in
+		 * GLOBAL_STATUS, and so the set of reserved bits is the same.
+		 */
+		if (data & pmu->global_status_mask)
 			return 1;
 
 		if (!msr_info->host_initiated)
@@ -531,7 +535,7 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 	pmu->reserved_bits = 0xffffffff00200000ull;
 	pmu->raw_event_mask = X86_RAW_EVENT_MASK;
 	pmu->global_ctrl_mask = ~0ull;
-	pmu->global_ovf_ctrl_mask = ~0ull;
+	pmu->global_status_mask = ~0ull;
 	pmu->fixed_ctr_ctrl_mask = ~0ull;
 	pmu->pebs_enable_mask = ~0ull;
 	pmu->pebs_data_cfg_mask = ~0ull;
@@ -585,11 +589,17 @@ static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 	counter_mask = ~(((1ull << pmu->nr_arch_gp_counters) - 1) |
 		(((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED));
 	pmu->global_ctrl_mask = counter_mask;
-	pmu->global_ovf_ctrl_mask = pmu->global_ctrl_mask
+
+	/*
+	 * GLOBAL_STATUS and GLOBAL_OVF_CONTROL (a.k.a. GLOBAL_STATUS_RESET)
+	 * share reserved bit definitions.  The kernel just happens to use
+	 * OVF_CTRL for the names.
+	 */
+	pmu->global_status_mask = pmu->global_ctrl_mask
 			& ~(MSR_CORE_PERF_GLOBAL_OVF_CTRL_OVF_BUF |
 			    MSR_CORE_PERF_GLOBAL_OVF_CTRL_COND_CHGD);
 	if (vmx_pt_mode_is_host_guest())
-		pmu->global_ovf_ctrl_mask &=
+		pmu->global_status_mask &=
 				~MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI;
 
 	entry = kvm_find_cpuid_entry_index(vcpu, 7, 0);

base-commit: b9846a698c9aff4eb2214a06ac83638ad098f33f
-- 
2.41.0.rc2.161.g9c6817b8e7-goog