From 4f1fa2a1bbeb2feca436d2c86bf6f78dc4e5e4c4 Mon Sep 17 00:00:00 2001 From: Like Xu Date: Mon, 19 Sep 2022 17:10:07 +0800 Subject: [PATCH] KVM: x86/pmu: Limit the maximum number of supported Intel GP counters The Intel Architectural IA32_PMCx MSRs addresses range allows for a maximum of 8 GP counters, and KVM cannot address any more. Introduce a local macro (named KVM_INTEL_PMC_MAX_GENERIC) and use it consistently to refer to the number of counters supported by KVM, thus avoiding possible out-of-bound accesses. Suggested-by: Jim Mattson Signed-off-by: Like Xu Reviewed-by: Jim Mattson Message-Id: <20220919091008.60695-2-likexu@tencent.com> Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 6 +++++- arch/x86/kvm/pmu.c | 2 +- arch/x86/kvm/vmx/pmu_intel.c | 4 ++-- arch/x86/kvm/x86.c | 12 +++++++----- 4 files changed, 15 insertions(+), 9 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 7551b6f9c31c..286f6130dcb4 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -501,6 +501,10 @@ struct kvm_pmc { bool intr; }; +/* More counters may conflict with other existing Architectural MSRs */ +#define KVM_INTEL_PMC_MAX_GENERIC 8 +#define MSR_ARCH_PERFMON_PERFCTR_MAX (MSR_ARCH_PERFMON_PERFCTR0 + KVM_INTEL_PMC_MAX_GENERIC - 1) +#define MSR_ARCH_PERFMON_EVENTSEL_MAX (MSR_ARCH_PERFMON_EVENTSEL0 + KVM_INTEL_PMC_MAX_GENERIC - 1) #define KVM_PMC_MAX_FIXED 3 struct kvm_pmu { unsigned nr_arch_gp_counters; @@ -516,7 +520,7 @@ struct kvm_pmu { u64 reserved_bits; u64 raw_event_mask; u8 version; - struct kvm_pmc gp_counters[INTEL_PMC_MAX_GENERIC]; + struct kvm_pmc gp_counters[KVM_INTEL_PMC_MAX_GENERIC]; struct kvm_pmc fixed_counters[KVM_PMC_MAX_FIXED]; struct irq_work irq_work; DECLARE_BITMAP(reprogram_pmi, X86_PMC_IDX_MAX); diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index d9b9a0f0db17..de1fd7369736 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -56,7 +56,7 @@ static const struct x86_cpu_id vmx_icl_pebs_cpu[] = { * code. Each pmc, stored in kvm_pmc.idx field, is unique across * all perf counters (both gp and fixed). The mapping relationship * between pmc and perf counters is as the following: - * * Intel: [0 .. INTEL_PMC_MAX_GENERIC-1] <=> gp counters + * * Intel: [0 .. KVM_INTEL_PMC_MAX_GENERIC-1] <=> gp counters * [INTEL_PMC_IDX_FIXED .. INTEL_PMC_IDX_FIXED + 2] <=> fixed * * AMD: [0 .. AMD64_NUM_COUNTERS-1] and, for families 15H * and later, [0 .. AMD64_NUM_COUNTERS_CORE-1] <=> gp counters diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 25b70a85bef5..10b33da9bd05 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -617,7 +617,7 @@ static void intel_pmu_init(struct kvm_vcpu *vcpu) struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); - for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) { + for (i = 0; i < KVM_INTEL_PMC_MAX_GENERIC; i++) { pmu->gp_counters[i].type = KVM_PMC_GP; pmu->gp_counters[i].vcpu = vcpu; pmu->gp_counters[i].idx = i; @@ -643,7 +643,7 @@ static void intel_pmu_reset(struct kvm_vcpu *vcpu) struct kvm_pmc *pmc = NULL; int i; - for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) { + for (i = 0; i < KVM_INTEL_PMC_MAX_GENERIC; i++) { pmc = &pmu->gp_counters[i]; pmc_stop_counter(pmc); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 73716fab120f..1e25f410d1fe 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1438,6 +1438,9 @@ static const u32 msrs_to_save_all[] = { MSR_ARCH_PERFMON_FIXED_CTR0 + 2, MSR_CORE_PERF_FIXED_CTR_CTRL, MSR_CORE_PERF_GLOBAL_STATUS, MSR_CORE_PERF_GLOBAL_CTRL, MSR_CORE_PERF_GLOBAL_OVF_CTRL, + MSR_IA32_PEBS_ENABLE, MSR_IA32_DS_AREA, MSR_PEBS_DATA_CFG, + + /* This part of MSRs should match KVM_INTEL_PMC_MAX_GENERIC. */ MSR_ARCH_PERFMON_PERFCTR0, MSR_ARCH_PERFMON_PERFCTR1, MSR_ARCH_PERFMON_PERFCTR0 + 2, MSR_ARCH_PERFMON_PERFCTR0 + 3, MSR_ARCH_PERFMON_PERFCTR0 + 4, MSR_ARCH_PERFMON_PERFCTR0 + 5, @@ -1446,7 +1449,6 @@ static const u32 msrs_to_save_all[] = { MSR_ARCH_PERFMON_EVENTSEL0 + 2, MSR_ARCH_PERFMON_EVENTSEL0 + 3, MSR_ARCH_PERFMON_EVENTSEL0 + 4, MSR_ARCH_PERFMON_EVENTSEL0 + 5, MSR_ARCH_PERFMON_EVENTSEL0 + 6, MSR_ARCH_PERFMON_EVENTSEL0 + 7, - MSR_IA32_PEBS_ENABLE, MSR_IA32_DS_AREA, MSR_PEBS_DATA_CFG, MSR_K7_EVNTSEL0, MSR_K7_EVNTSEL1, MSR_K7_EVNTSEL2, MSR_K7_EVNTSEL3, MSR_K7_PERFCTR0, MSR_K7_PERFCTR1, MSR_K7_PERFCTR2, MSR_K7_PERFCTR3, @@ -7031,14 +7033,14 @@ static void kvm_init_msr_list(void) intel_pt_validate_hw_cap(PT_CAP_num_address_ranges) * 2) continue; break; - case MSR_ARCH_PERFMON_PERFCTR0 ... MSR_ARCH_PERFMON_PERFCTR0 + 7: + case MSR_ARCH_PERFMON_PERFCTR0 ... MSR_ARCH_PERFMON_PERFCTR_MAX: if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_PERFCTR0 >= - min(INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp)) + min(KVM_INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp)) continue; break; - case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL0 + 7: + case MSR_ARCH_PERFMON_EVENTSEL0 ... MSR_ARCH_PERFMON_EVENTSEL_MAX: if (msrs_to_save_all[i] - MSR_ARCH_PERFMON_EVENTSEL0 >= - min(INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp)) + min(KVM_INTEL_PMC_MAX_GENERIC, kvm_pmu_cap.num_counters_gp)) continue; break; case MSR_IA32_XFD: -- 2.20.1