From: Dapeng Mi dapeng1.mi@linux.intel.com
This patch supports to switch host/guest PMU context at vm-exit/vm-entry for mediated vPMU.
In details, kvm_pmu_put_guest_context() is called to save guest PMU context and load host PMU context at VM-exits and kvm_pmu_load_guest_context() is called to save host PMU context and load guest PMU context at vm-entries.
A pair of pmu_ops callbacks *put_guest_context() and *load_guest_context() are added to save/restore vendor specific PMU MSRs.
Co-developed-by: Mingwei Zhang mizhang@google.com Signed-off-by: Mingwei Zhang mizhang@google.com Co-developed-by: Sandipan Das sandipan.das@amd.com Signed-off-by: Sandipan Das sandipan.das@amd.com Signed-off-by: Dapeng Mi dapeng1.mi@linux.intel.com --- arch/x86/include/asm/kvm-x86-pmu-ops.h | 2 + arch/x86/include/asm/kvm_host.h | 4 ++ arch/x86/include/asm/msr-index.h | 1 + arch/x86/kvm/pmu.c | 96 ++++++++++++++++++++++++++ arch/x86/kvm/pmu.h | 11 +++ arch/x86/kvm/svm/pmu.c | 54 +++++++++++++++ arch/x86/kvm/vmx/pmu_intel.c | 59 ++++++++++++++++ arch/x86/kvm/x86.c | 4 ++ 8 files changed, 231 insertions(+)
diff --git a/arch/x86/include/asm/kvm-x86-pmu-ops.h b/arch/x86/include/asm/kvm-x86-pmu-ops.h index 9159bf1a4730..35f27366c277 100644 --- a/arch/x86/include/asm/kvm-x86-pmu-ops.h +++ b/arch/x86/include/asm/kvm-x86-pmu-ops.h @@ -22,6 +22,8 @@ KVM_X86_PMU_OP(init) KVM_X86_PMU_OP_OPTIONAL(reset) KVM_X86_PMU_OP_OPTIONAL(deliver_pmi) KVM_X86_PMU_OP_OPTIONAL(cleanup) +KVM_X86_PMU_OP(put_guest_context) +KVM_X86_PMU_OP(load_guest_context)
#undef KVM_X86_PMU_OP #undef KVM_X86_PMU_OP_OPTIONAL diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 7ee74bbbb0aa..4117a382739a 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -568,6 +568,10 @@ struct kvm_pmu { u64 raw_event_mask; struct kvm_pmc gp_counters[KVM_MAX_NR_GP_COUNTERS]; struct kvm_pmc fixed_counters[KVM_MAX_NR_FIXED_COUNTERS]; + u32 gp_eventsel_base; + u32 gp_counter_base; + u32 fixed_base; + u32 cntr_shift;
/* * Overlay the bitmap with a 64-bit atomic so that all bits can be diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index a4d8356e9b53..df33a4f026a1 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -1153,6 +1153,7 @@ #define MSR_CORE_PERF_GLOBAL_STATUS 0x0000038e #define MSR_CORE_PERF_GLOBAL_CTRL 0x0000038f #define MSR_CORE_PERF_GLOBAL_OVF_CTRL 0x00000390 +#define MSR_CORE_PERF_GLOBAL_STATUS_SET 0x00000391
#define MSR_PERF_METRICS 0x00000329
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index e9100dc49fdc..68f203454bbc 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -1127,3 +1127,99 @@ int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp) kfree(filter); return r; } + +void kvm_pmu_put_guest_pmcs(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + u32 eventsel_msr; + u32 counter_msr; + u32 i; + + /* + * Clear hardware selector MSR content and its counter to avoid + * leakage and also avoid this guest GP counter get accidentally + * enabled during host running when host enable global ctrl. + */ + for (i = 0; i < pmu->nr_arch_gp_counters; i++) { + pmc = &pmu->gp_counters[i]; + eventsel_msr = pmc_msr_addr(pmu, pmu->gp_eventsel_base, i); + counter_msr = pmc_msr_addr(pmu, pmu->gp_counter_base, i); + + rdpmcl(i, pmc->counter); + rdmsrl(eventsel_msr, pmc->eventsel_hw); + if (pmc->counter) + wrmsrl(counter_msr, 0); + if (pmc->eventsel_hw) + wrmsrl(eventsel_msr, 0); + } + + for (i = 0; i < pmu->nr_arch_fixed_counters; i++) { + pmc = &pmu->fixed_counters[i]; + counter_msr = pmc_msr_addr(pmu, pmu->fixed_base, i); + + rdpmcl(INTEL_PMC_FIXED_RDPMC_BASE | i, pmc->counter); + if (pmc->counter) + wrmsrl(counter_msr, 0); + } + +} +EXPORT_SYMBOL_GPL(kvm_pmu_put_guest_pmcs); + +void kvm_pmu_load_guest_pmcs(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + u32 eventsel_msr; + u32 counter_msr; + u32 i; + + /* + * No need to zero out unexposed GP/fixed counters/selectors since RDPMC + * in this case will be intercepted. Accessing to these counters and + * selectors will cause #GP in the guest. + */ + for (i = 0; i < pmu->nr_arch_gp_counters; i++) { + pmc = &pmu->gp_counters[i]; + eventsel_msr = pmc_msr_addr(pmu, pmu->gp_eventsel_base, i); + counter_msr = pmc_msr_addr(pmu, pmu->gp_counter_base, i); + + wrmsrl(counter_msr, pmc->counter); + wrmsrl(eventsel_msr, pmc->eventsel_hw); + } + for (i = 0; i < pmu->nr_arch_fixed_counters; i++) { + pmc = &pmu->fixed_counters[i]; + counter_msr = pmc_msr_addr(pmu, pmu->fixed_base, i); + + wrmsrl(counter_msr, pmc->counter); + } +} +EXPORT_SYMBOL_GPL(kvm_pmu_load_guest_pmcs); + +void kvm_pmu_put_guest_context(struct kvm_vcpu *vcpu) +{ + if (!kvm_mediated_pmu_enabled(vcpu)) + return; + + lockdep_assert_irqs_disabled(); + + kvm_pmu_call(put_guest_context)(vcpu); + + perf_guest_exit(); +} + +void kvm_pmu_load_guest_context(struct kvm_vcpu *vcpu) +{ + u32 guest_lvtpc; + + if (!kvm_mediated_pmu_enabled(vcpu)) + return; + + lockdep_assert_irqs_disabled(); + + guest_lvtpc = APIC_DM_FIXED | KVM_GUEST_PMI_VECTOR | + (kvm_lapic_get_reg(vcpu->arch.apic, APIC_LVTPC) & APIC_LVT_MASKED); + perf_guest_enter(guest_lvtpc); + + kvm_pmu_call(load_guest_context)(vcpu); +} diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h index 6289f523d893..d5da3a9a3bd5 100644 --- a/arch/x86/kvm/pmu.h +++ b/arch/x86/kvm/pmu.h @@ -41,6 +41,8 @@ struct kvm_pmu_ops { void (*reset)(struct kvm_vcpu *vcpu); void (*deliver_pmi)(struct kvm_vcpu *vcpu); void (*cleanup)(struct kvm_vcpu *vcpu); + void (*put_guest_context)(struct kvm_vcpu *vcpu); + void (*load_guest_context)(struct kvm_vcpu *vcpu);
const u64 EVENTSEL_EVENT; const int MAX_NR_GP_COUNTERS; @@ -292,6 +294,11 @@ static inline bool kvm_host_has_perf_metrics(void) return !!(kvm_host.perf_capabilities & PERF_CAP_PERF_METRICS); }
+static inline u32 pmc_msr_addr(struct kvm_pmu *pmu, u32 base, int idx) +{ + return base + idx * pmu->cntr_shift; +} + void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu); void kvm_pmu_handle_event(struct kvm_vcpu *vcpu); int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data); @@ -306,6 +313,10 @@ void kvm_pmu_destroy(struct kvm_vcpu *vcpu); int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp); void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, u64 eventsel); bool vcpu_pmu_can_enable(struct kvm_vcpu *vcpu); +void kvm_pmu_put_guest_pmcs(struct kvm_vcpu *vcpu); +void kvm_pmu_load_guest_pmcs(struct kvm_vcpu *vcpu); +void kvm_pmu_put_guest_context(struct kvm_vcpu *vcpu); +void kvm_pmu_load_guest_context(struct kvm_vcpu *vcpu);
bool is_vmware_backdoor_pmc(u32 pmc_idx); bool kvm_rdpmc_in_guest(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c index 1a7e3a897fdf..7e0d84d50b74 100644 --- a/arch/x86/kvm/svm/pmu.c +++ b/arch/x86/kvm/svm/pmu.c @@ -175,6 +175,22 @@ static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) return 1; }
+static inline void amd_update_msr_base(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + + if (kvm_pmu_has_perf_global_ctrl(pmu) || + guest_cpu_cap_has(vcpu, X86_FEATURE_PERFCTR_CORE)) { + pmu->gp_eventsel_base = MSR_F15H_PERF_CTL0; + pmu->gp_counter_base = MSR_F15H_PERF_CTR0; + pmu->cntr_shift = 2; + } else { + pmu->gp_eventsel_base = MSR_K7_EVNTSEL0; + pmu->gp_counter_base = MSR_K7_PERFCTR0; + pmu->cntr_shift = 1; + } +} + static void __amd_pmu_refresh(struct kvm_vcpu *vcpu) { struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); @@ -220,6 +236,8 @@ static void __amd_pmu_refresh(struct kvm_vcpu *vcpu) pmu->counter_bitmask[KVM_PMC_FIXED] = 0; pmu->nr_arch_fixed_counters = 0; bitmap_set(pmu->all_valid_pmc_idx, 0, pmu->nr_arch_gp_counters); + + amd_update_msr_base(vcpu); }
static void amd_pmu_update_msr_intercepts(struct kvm_vcpu *vcpu) @@ -312,6 +330,40 @@ static void amd_pmu_init(struct kvm_vcpu *vcpu) } }
+ +static void amd_put_guest_context(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + + rdmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_CTL, pmu->global_ctrl); + wrmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_CTL, 0); + rdmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS, pmu->global_status); + + /* Clear global status bits if non-zero */ + if (pmu->global_status) + wrmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR, pmu->global_status); + + kvm_pmu_put_guest_pmcs(vcpu); +} + +static void amd_load_guest_context(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + u64 global_status; + + wrmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_CTL, 0); + + kvm_pmu_load_guest_pmcs(vcpu); + + rdmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS, global_status); + /* Clear host global_status MSR if non-zero. */ + if (global_status) + wrmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR, global_status); + + wrmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET, pmu->global_status); + wrmsrl(MSR_AMD64_PERF_CNTR_GLOBAL_CTL, pmu->global_ctrl); +} + struct kvm_pmu_ops amd_pmu_ops __initdata = { .rdpmc_ecx_to_pmc = amd_rdpmc_ecx_to_pmc, .msr_idx_to_pmc = amd_msr_idx_to_pmc, @@ -321,6 +373,8 @@ struct kvm_pmu_ops amd_pmu_ops __initdata = { .set_msr = amd_pmu_set_msr, .refresh = amd_pmu_refresh, .init = amd_pmu_init, + .put_guest_context = amd_put_guest_context, + .load_guest_context = amd_load_guest_context, .EVENTSEL_EVENT = AMD64_EVENTSEL_EVENT, .MAX_NR_GP_COUNTERS = KVM_MAX_NR_AMD_GP_COUNTERS, .MIN_NR_GP_COUNTERS = AMD64_NUM_COUNTERS, diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 796b7bc4affe..ed17ab198dfb 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -460,6 +460,17 @@ static void intel_pmu_enable_fixed_counter_bits(struct kvm_pmu *pmu, u64 bits) pmu->fixed_ctr_ctrl_rsvd &= ~intel_fixed_bits_by_idx(i, bits); }
+static inline void intel_update_msr_base(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + + pmu->gp_eventsel_base = MSR_P6_EVNTSEL0; + pmu->gp_counter_base = fw_writes_is_enabled(vcpu) ? + MSR_IA32_PMC0 : MSR_IA32_PERFCTR0; + pmu->fixed_base = MSR_CORE_PERF_FIXED_CTR0; + pmu->cntr_shift = 1; +} + static void __intel_pmu_refresh(struct kvm_vcpu *vcpu) { struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); @@ -567,6 +578,8 @@ static void __intel_pmu_refresh(struct kvm_vcpu *vcpu) pmu->pebs_enable_rsvd = ~(BIT_ULL(pmu->nr_arch_gp_counters) - 1); } } + + intel_update_msr_base(vcpu); }
static void intel_pmu_update_msr_intercepts(struct kvm_vcpu *vcpu) @@ -809,6 +822,50 @@ void intel_pmu_cross_mapped_check(struct kvm_pmu *pmu) } }
+static void intel_put_guest_context(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + + /* Global ctrl register is already saved at VM-exit. */ + rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, pmu->global_status); + + /* Clear hardware MSR_CORE_PERF_GLOBAL_STATUS MSR, if non-zero. */ + if (pmu->global_status) + wrmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, pmu->global_status); + + rdmsrl(MSR_CORE_PERF_FIXED_CTR_CTRL, pmu->fixed_ctr_ctrl_hw); + + /* + * Clear hardware FIXED_CTR_CTRL MSR to avoid information leakage and + * also avoid these guest fixed counters get accidentially enabled + * during host running when host enable global ctrl. + */ + if (pmu->fixed_ctr_ctrl_hw) + wrmsrl(MSR_CORE_PERF_FIXED_CTR_CTRL, 0); + + kvm_pmu_put_guest_pmcs(vcpu); +} + +static void intel_load_guest_context(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + u64 global_status, toggle; + + /* Clear host global_ctrl MSR if non-zero. */ + wrmsrl(MSR_CORE_PERF_GLOBAL_CTRL, 0); + + rdmsrl(MSR_CORE_PERF_GLOBAL_STATUS, global_status); + toggle = pmu->global_status ^ global_status; + if (global_status & toggle) + wrmsrl(MSR_CORE_PERF_GLOBAL_OVF_CTRL, global_status & toggle); + if (pmu->global_status & toggle) + wrmsrl(MSR_CORE_PERF_GLOBAL_STATUS_SET, pmu->global_status & toggle); + + wrmsrl(MSR_CORE_PERF_FIXED_CTR_CTRL, pmu->fixed_ctr_ctrl_hw); + + kvm_pmu_load_guest_pmcs(vcpu); +} + struct kvm_pmu_ops intel_pmu_ops __initdata = { .rdpmc_ecx_to_pmc = intel_rdpmc_ecx_to_pmc, .msr_idx_to_pmc = intel_msr_idx_to_pmc, @@ -820,6 +877,8 @@ struct kvm_pmu_ops intel_pmu_ops __initdata = { .reset = intel_pmu_reset, .deliver_pmi = intel_pmu_deliver_pmi, .cleanup = intel_pmu_cleanup, + .put_guest_context = intel_put_guest_context, + .load_guest_context = intel_load_guest_context, .EVENTSEL_EVENT = ARCH_PERFMON_EVENTSEL_EVENT, .MAX_NR_GP_COUNTERS = KVM_MAX_NR_INTEL_GP_COUNTERS, .MIN_NR_GP_COUNTERS = 1, diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 578e5f110b6c..d35afa8d9cbb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10998,6 +10998,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) set_debugreg(0, 7); }
+ kvm_pmu_load_guest_context(vcpu); + guest_timing_enter_irqoff();
for (;;) { @@ -11027,6 +11029,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) ++vcpu->stat.exits; }
+ kvm_pmu_put_guest_context(vcpu); + /* * Do this here before restoring debug registers on the host. And * since we do this before handling the vmexit, a DR access vmexit