linux-kernel - [PATCH] KVM: x86/pmu: Drop event_type and rename "struct kvm_event_hw_type

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Message-Id: <20221205122048.16023-1-likexu@tencent.com>
Date:   Mon,  5 Dec 2022 20:20:48 +0800
From:   Like Xu <like.xu.linux@...il.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] KVM: x86/pmu: Drop event_type and rename "struct kvm_event_hw_type_mapping"

From: Like Xu <likexu@...cent.com>

After commit ("02791a5c362b KVM: x86/pmu: Use PERF_TYPE_RAW
to merge reprogram_{gp,fixed}counter()"), vPMU starts to directly
use the hardware event eventsel and unit_mask to reprogram perf_event,
and the event_type field in the "struct kvm_event_hw_type_mapping"
is simply no longer being used.

After discarding this field, the name of the structure also lost
its mapping semantics, renaming it "struct kvm_pmu_hw_event" and
reorganizing the comments to continue to help newcomers.

Signed-off-by: Like Xu <likexu@...cent.com>
---
 arch/x86/kvm/pmu.h           |  3 +--
 arch/x86/kvm/vmx/pmu_intel.c | 34 +++++++++++++++++++++++++---------
 2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index 85ff3c0588ba..2aef09eafb70 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -18,10 +18,9 @@
 #define VMWARE_BACKDOOR_PMC_REAL_TIME		0x10001
 #define VMWARE_BACKDOOR_PMC_APPARENT_TIME	0x10002
 
-struct kvm_event_hw_type_mapping {
+struct kvm_pmu_hw_event {
 	u8 eventsel;
 	u8 unit_mask;
-	unsigned event_type;
 };
 
 struct kvm_pmu_ops {
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 28b0a784f6e9..d34e9f85bdce 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -20,16 +20,32 @@
 
 #define MSR_PMC_FULL_WIDTH_BIT      (MSR_IA32_PMC0 - MSR_IA32_PERFCTR0)
 
-static struct kvm_event_hw_type_mapping intel_arch_events[] = {
-	[0] = { 0x3c, 0x00, PERF_COUNT_HW_CPU_CYCLES },
-	[1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS },
-	[2] = { 0x3c, 0x01, PERF_COUNT_HW_BUS_CYCLES  },
-	[3] = { 0x2e, 0x4f, PERF_COUNT_HW_CACHE_REFERENCES },
-	[4] = { 0x2e, 0x41, PERF_COUNT_HW_CACHE_MISSES },
-	[5] = { 0xc4, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
-	[6] = { 0xc5, 0x00, PERF_COUNT_HW_BRANCH_MISSES },
+/*
+ * The first part of hw_events in the following array represent Intel's
+ * Pre-defined Architectural Performance Events in an ordered manner:
+ *
+ * 0 - PERF_COUNT_HW_CPU_CYCLES
+ * 1 - PERF_COUNT_HW_INSTRUCTIONS
+ * 2 - PERF_COUNT_HW_BUS_CYCLES
+ * 3 - PERF_COUNT_HW_CACHE_REFERENCES
+ * 4 - PERF_COUNT_HW_CACHE_MISSES
+ * 5 - PERF_COUNT_HW_BRANCH_INSTRUCTIONS
+ * 6 - PERF_COUNT_HW_BRANCH_MISSES
+ *
+ * the second part of hw_events is defined by the generic kernel perf:
+ *
+ * 7 - PERF_COUNT_HW_REF_CPU_CYCLES
+ */
+static struct kvm_pmu_hw_event intel_arch_events[] = {
+	[0] = { 0x3c, 0x00 },
+	[1] = { 0xc0, 0x00 },
+	[2] = { 0x3c, 0x01 },
+	[3] = { 0x2e, 0x4f },
+	[4] = { 0x2e, 0x41 },
+	[5] = { 0xc4, 0x00 },
+	[6] = { 0xc5, 0x00 },
 	/* The above index must match CPUID 0x0A.EBX bit vector */
-	[7] = { 0x00, 0x03, PERF_COUNT_HW_REF_CPU_CYCLES },
+	[7] = { 0x00, 0x03 },
 };
 
 /* mapping between fixed pmc index and intel_arch_events array */
-- 
2.38.1