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[RFC,v3,42/58] KVM: x86/pmu: Introduce PMU operator to increment counter

Message ID 20240801045907.4010984-43-mizhang@google.com (mailing list archive)
State New, archived
Headers show
Series Mediated Passthrough vPMU 3.0 for x86 | expand

Commit Message

Mingwei Zhang Aug. 1, 2024, 4:58 a.m. UTC 
Introduce PMU operator to increment counter because in passthrough PMU
there is no common backend implementation like host perf API. Having a PMU
operator for counter increment and overflow checking will help hiding
architectural differences.

So Introduce the operator function to make it convenient for passthrough
PMU to synthesize a PMI.

Signed-off-by: Mingwei Zhang <mizhang@google.com>
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
---
 arch/x86/include/asm/kvm-x86-pmu-ops.h |  1 +
 arch/x86/kvm/pmu.h                     |  1 +
 arch/x86/kvm/vmx/pmu_intel.c           | 12 ++++++++++++
 3 files changed, 14 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/include/asm/kvm-x86-pmu-ops.h b/arch/x86/include/asm/kvm-x86-pmu-ops.h
index 1a848ba6a7a7..72ca78df8d2b 100644
--- a/arch/x86/include/asm/kvm-x86-pmu-ops.h
+++ b/arch/x86/include/asm/kvm-x86-pmu-ops.h
@@ -27,6 +27,7 @@  KVM_X86_PMU_OP_OPTIONAL(cleanup)
 KVM_X86_PMU_OP_OPTIONAL(passthrough_pmu_msrs)
 KVM_X86_PMU_OP_OPTIONAL(save_pmu_context)
 KVM_X86_PMU_OP_OPTIONAL(restore_pmu_context)
+KVM_X86_PMU_OP_OPTIONAL(incr_counter)
 
 #undef KVM_X86_PMU_OP
 #undef KVM_X86_PMU_OP_OPTIONAL
diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h
index 9cde62f3988e..325f17673a00 100644
--- a/arch/x86/kvm/pmu.h
+++ b/arch/x86/kvm/pmu.h
@@ -44,6 +44,7 @@  struct kvm_pmu_ops {
 	void (*passthrough_pmu_msrs)(struct kvm_vcpu *vcpu);
 	void (*save_pmu_context)(struct kvm_vcpu *vcpu);
 	void (*restore_pmu_context)(struct kvm_vcpu *vcpu);
+	bool (*incr_counter)(struct kvm_pmc *pmc);
 
 	const u64 EVENTSEL_EVENT;
 	const int MAX_NR_GP_COUNTERS;
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index 40c503cd263b..42af2404bdb9 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -74,6 +74,17 @@  static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
 	}
 }
 
+static bool intel_incr_counter(struct kvm_pmc *pmc)
+{
+	pmc->counter += 1;
+	pmc->counter &= pmc_bitmask(pmc);
+
+	if (!pmc->counter)
+		return true;
+
+	return false;
+}
+
 static struct kvm_pmc *intel_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu,
 					    unsigned int idx, u64 *mask)
 {
@@ -885,6 +896,7 @@  struct kvm_pmu_ops intel_pmu_ops __initdata = {
 	.passthrough_pmu_msrs = intel_passthrough_pmu_msrs,
 	.save_pmu_context = intel_save_guest_pmu_context,
 	.restore_pmu_context = intel_restore_guest_pmu_context,
+	.incr_counter = intel_incr_counter,
 	.EVENTSEL_EVENT = ARCH_PERFMON_EVENTSEL_EVENT,
 	.MAX_NR_GP_COUNTERS = KVM_INTEL_PMC_MAX_GENERIC,
 	.MIN_NR_GP_COUNTERS = 1,