diff options
Diffstat (limited to 'arch/x86/kvm/vmx/pmu_intel.c')
| -rw-r--r-- | arch/x86/kvm/vmx/pmu_intel.c | 784 |
1 files changed, 784 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c new file mode 100644 index 000000000000..de1d9785c01f --- /dev/null +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -0,0 +1,784 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * KVM PMU support for Intel CPUs + * + * Copyright 2011 Red Hat, Inc. and/or its affiliates. + * + * Authors: + * Avi Kivity <avi@redhat.com> + * Gleb Natapov <gleb@redhat.com> + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/types.h> +#include <linux/kvm_host.h> +#include <linux/perf_event.h> +#include <asm/msr.h> +#include <asm/perf_event.h> +#include "x86.h" +#include "cpuid.h" +#include "lapic.h" +#include "nested.h" +#include "pmu.h" +#include "tdx.h" + +/* + * Perf's "BASE" is wildly misleading, architectural PMUs use bits 31:16 of ECX + * to encode the "type" of counter to read, i.e. this is not a "base". And to + * further confuse things, non-architectural PMUs use bit 31 as a flag for + * "fast" reads, whereas the "type" is an explicit value. + */ +#define INTEL_RDPMC_GP 0 +#define INTEL_RDPMC_FIXED INTEL_PMC_FIXED_RDPMC_BASE + +#define INTEL_RDPMC_TYPE_MASK GENMASK(31, 16) +#define INTEL_RDPMC_INDEX_MASK GENMASK(15, 0) + +#define MSR_PMC_FULL_WIDTH_BIT (MSR_IA32_PMC0 - MSR_IA32_PERFCTR0) + +static struct lbr_desc *vcpu_to_lbr_desc(struct kvm_vcpu *vcpu) +{ + if (is_td_vcpu(vcpu)) + return NULL; + + return &to_vmx(vcpu)->lbr_desc; +} + +static struct x86_pmu_lbr *vcpu_to_lbr_records(struct kvm_vcpu *vcpu) +{ + if (is_td_vcpu(vcpu)) + return NULL; + + return &to_vmx(vcpu)->lbr_desc.records; +} + +#pragma GCC poison to_vmx + +static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data) +{ + struct kvm_pmc *pmc; + u64 old_fixed_ctr_ctrl = pmu->fixed_ctr_ctrl; + int i; + + pmu->fixed_ctr_ctrl = data; + for (i = 0; i < pmu->nr_arch_fixed_counters; i++) { + u8 new_ctrl = fixed_ctrl_field(data, i); + u8 old_ctrl = fixed_ctrl_field(old_fixed_ctr_ctrl, i); + + if (old_ctrl == new_ctrl) + continue; + + pmc = get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + i); + + __set_bit(KVM_FIXED_PMC_BASE_IDX + i, pmu->pmc_in_use); + kvm_pmu_request_counter_reprogram(pmc); + } +} + +static struct kvm_pmc *intel_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu, + unsigned int idx, u64 *mask) +{ + unsigned int type = idx & INTEL_RDPMC_TYPE_MASK; + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *counters; + unsigned int num_counters; + u64 bitmask; + + /* + * The encoding of ECX for RDPMC is different for architectural versus + * non-architecturals PMUs (PMUs with version '0'). For architectural + * PMUs, bits 31:16 specify the PMC type and bits 15:0 specify the PMC + * index. For non-architectural PMUs, bit 31 is a "fast" flag, and + * bits 30:0 specify the PMC index. + * + * Yell and reject attempts to read PMCs for a non-architectural PMU, + * as KVM doesn't support such PMUs. + */ + if (WARN_ON_ONCE(!pmu->version)) + return NULL; + + /* + * General Purpose (GP) PMCs are supported on all PMUs, and fixed PMCs + * are supported on all architectural PMUs, i.e. on all virtual PMUs + * supported by KVM. Note, KVM only emulates fixed PMCs for PMU v2+, + * but the type itself is still valid, i.e. let RDPMC fail due to + * accessing a non-existent counter. Reject attempts to read all other + * types, which are unknown/unsupported. + */ + switch (type) { + case INTEL_RDPMC_FIXED: + counters = pmu->fixed_counters; + num_counters = pmu->nr_arch_fixed_counters; + bitmask = pmu->counter_bitmask[KVM_PMC_FIXED]; + break; + case INTEL_RDPMC_GP: + counters = pmu->gp_counters; + num_counters = pmu->nr_arch_gp_counters; + bitmask = pmu->counter_bitmask[KVM_PMC_GP]; + break; + default: + return NULL; + } + + idx &= INTEL_RDPMC_INDEX_MASK; + if (idx >= num_counters) + return NULL; + + *mask &= bitmask; + return &counters[array_index_nospec(idx, num_counters)]; +} + +static inline u64 vcpu_get_perf_capabilities(struct kvm_vcpu *vcpu) +{ + if (!guest_cpu_cap_has(vcpu, X86_FEATURE_PDCM)) + return 0; + + return vcpu->arch.perf_capabilities; +} + +static inline bool fw_writes_is_enabled(struct kvm_vcpu *vcpu) +{ + return (vcpu_get_perf_capabilities(vcpu) & PERF_CAP_FW_WRITES) != 0; +} + +static inline struct kvm_pmc *get_fw_gp_pmc(struct kvm_pmu *pmu, u32 msr) +{ + if (!fw_writes_is_enabled(pmu_to_vcpu(pmu))) + return NULL; + + return get_gp_pmc(pmu, msr, MSR_IA32_PMC0); +} + +static bool intel_pmu_lbr_is_compatible(struct kvm_vcpu *vcpu) +{ + if (is_td_vcpu(vcpu)) + return false; + + return cpuid_model_is_consistent(vcpu); +} + +bool intel_pmu_lbr_is_enabled(struct kvm_vcpu *vcpu) +{ + if (is_td_vcpu(vcpu)) + return false; + + return !!vcpu_to_lbr_records(vcpu)->nr; +} + +static bool intel_pmu_is_valid_lbr_msr(struct kvm_vcpu *vcpu, u32 index) +{ + struct x86_pmu_lbr *records = vcpu_to_lbr_records(vcpu); + bool ret = false; + + if (!intel_pmu_lbr_is_enabled(vcpu)) + return ret; + + ret = (index == MSR_LBR_SELECT) || (index == MSR_LBR_TOS) || + (index >= records->from && index < records->from + records->nr) || + (index >= records->to && index < records->to + records->nr); + + if (!ret && records->info) + ret = (index >= records->info && index < records->info + records->nr); + + return ret; +} + +static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + u64 perf_capabilities; + int ret; + + switch (msr) { + case MSR_CORE_PERF_FIXED_CTR_CTRL: + return kvm_pmu_has_perf_global_ctrl(pmu); + case MSR_IA32_PEBS_ENABLE: + ret = vcpu_get_perf_capabilities(vcpu) & PERF_CAP_PEBS_FORMAT; + break; + case MSR_IA32_DS_AREA: + ret = guest_cpu_cap_has(vcpu, X86_FEATURE_DS); + break; + case MSR_PEBS_DATA_CFG: + perf_capabilities = vcpu_get_perf_capabilities(vcpu); + ret = (perf_capabilities & PERF_CAP_PEBS_BASELINE) && + ((perf_capabilities & PERF_CAP_PEBS_FORMAT) > 3); + break; + default: + ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) || + get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) || + get_fixed_pmc(pmu, msr) || get_fw_gp_pmc(pmu, msr) || + intel_pmu_is_valid_lbr_msr(vcpu, msr); + break; + } + + return ret; +} + +static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu, u32 msr) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + + pmc = get_fixed_pmc(pmu, msr); + pmc = pmc ? pmc : get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0); + pmc = pmc ? pmc : get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0); + + return pmc; +} + +static inline void intel_pmu_release_guest_lbr_event(struct kvm_vcpu *vcpu) +{ + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + + if (!lbr_desc) + return; + + if (lbr_desc->event) { + perf_event_release_kernel(lbr_desc->event); + lbr_desc->event = NULL; + vcpu_to_pmu(vcpu)->event_count--; + } +} + +int intel_pmu_create_guest_lbr_event(struct kvm_vcpu *vcpu) +{ + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct perf_event *event; + + /* + * The perf_event_attr is constructed in the minimum efficient way: + * - set 'pinned = true' to make it task pinned so that if another + * cpu pinned event reclaims LBR, the event->oncpu will be set to -1; + * - set '.exclude_host = true' to record guest branches behavior; + * + * - set '.config = INTEL_FIXED_VLBR_EVENT' to indicates host perf + * schedule the event without a real HW counter but a fake one; + * check is_guest_lbr_event() and __intel_get_event_constraints(); + * + * - set 'sample_type = PERF_SAMPLE_BRANCH_STACK' and + * 'branch_sample_type = PERF_SAMPLE_BRANCH_CALL_STACK | + * PERF_SAMPLE_BRANCH_USER' to configure it as a LBR callstack + * event, which helps KVM to save/restore guest LBR records + * during host context switches and reduces quite a lot overhead, + * check branch_user_callstack() and intel_pmu_lbr_sched_task(); + */ + struct perf_event_attr attr = { + .type = PERF_TYPE_RAW, + .size = sizeof(attr), + .config = INTEL_FIXED_VLBR_EVENT, + .sample_type = PERF_SAMPLE_BRANCH_STACK, + .pinned = true, + .exclude_host = true, + .branch_sample_type = PERF_SAMPLE_BRANCH_CALL_STACK | + PERF_SAMPLE_BRANCH_USER, + }; + + if (WARN_ON_ONCE(!lbr_desc)) + return 0; + + if (unlikely(lbr_desc->event)) { + __set_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use); + return 0; + } + + event = perf_event_create_kernel_counter(&attr, -1, + current, NULL, NULL); + if (IS_ERR(event)) { + pr_debug_ratelimited("%s: failed %ld\n", + __func__, PTR_ERR(event)); + return PTR_ERR(event); + } + lbr_desc->event = event; + pmu->event_count++; + __set_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use); + return 0; +} + +/* + * It's safe to access LBR msrs from guest when they have not + * been passthrough since the host would help restore or reset + * the LBR msrs records when the guest LBR event is scheduled in. + */ +static bool intel_pmu_handle_lbr_msrs_access(struct kvm_vcpu *vcpu, + struct msr_data *msr_info, bool read) +{ + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + u32 index = msr_info->index; + + if (!intel_pmu_is_valid_lbr_msr(vcpu, index)) + return false; + + if (!lbr_desc->event && intel_pmu_create_guest_lbr_event(vcpu) < 0) + goto dummy; + + /* + * Disable irq to ensure the LBR feature doesn't get reclaimed by the + * host at the time the value is read from the msr, and this avoids the + * host LBR value to be leaked to the guest. If LBR has been reclaimed, + * return 0 on guest reads. + */ + local_irq_disable(); + if (lbr_desc->event->state == PERF_EVENT_STATE_ACTIVE) { + if (read) + rdmsrq(index, msr_info->data); + else + wrmsrq(index, msr_info->data); + __set_bit(INTEL_PMC_IDX_FIXED_VLBR, vcpu_to_pmu(vcpu)->pmc_in_use); + local_irq_enable(); + return true; + } + clear_bit(INTEL_PMC_IDX_FIXED_VLBR, vcpu_to_pmu(vcpu)->pmc_in_use); + local_irq_enable(); + +dummy: + if (read) + msr_info->data = 0; + return true; +} + +static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + u32 msr = msr_info->index; + + switch (msr) { + case MSR_CORE_PERF_FIXED_CTR_CTRL: + msr_info->data = pmu->fixed_ctr_ctrl; + break; + case MSR_IA32_PEBS_ENABLE: + msr_info->data = pmu->pebs_enable; + break; + case MSR_IA32_DS_AREA: + msr_info->data = pmu->ds_area; + break; + case MSR_PEBS_DATA_CFG: + msr_info->data = pmu->pebs_data_cfg; + break; + default: + if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) || + (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) { + u64 val = pmc_read_counter(pmc); + msr_info->data = + val & pmu->counter_bitmask[KVM_PMC_GP]; + break; + } else if ((pmc = get_fixed_pmc(pmu, msr))) { + u64 val = pmc_read_counter(pmc); + msr_info->data = + val & pmu->counter_bitmask[KVM_PMC_FIXED]; + break; + } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) { + msr_info->data = pmc->eventsel; + break; + } else if (intel_pmu_handle_lbr_msrs_access(vcpu, msr_info, true)) { + break; + } + return 1; + } + + return 0; +} + +static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + u32 msr = msr_info->index; + u64 data = msr_info->data; + u64 reserved_bits, diff; + + switch (msr) { + case MSR_CORE_PERF_FIXED_CTR_CTRL: + if (data & pmu->fixed_ctr_ctrl_rsvd) + return 1; + + if (pmu->fixed_ctr_ctrl != data) + reprogram_fixed_counters(pmu, data); + break; + case MSR_IA32_PEBS_ENABLE: + if (data & pmu->pebs_enable_rsvd) + return 1; + + if (pmu->pebs_enable != data) { + diff = pmu->pebs_enable ^ data; + pmu->pebs_enable = data; + reprogram_counters(pmu, diff); + } + break; + case MSR_IA32_DS_AREA: + if (is_noncanonical_msr_address(data, vcpu)) + return 1; + + pmu->ds_area = data; + break; + case MSR_PEBS_DATA_CFG: + if (data & pmu->pebs_data_cfg_rsvd) + return 1; + + pmu->pebs_data_cfg = data; + break; + default: + if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) || + (pmc = get_gp_pmc(pmu, msr, MSR_IA32_PMC0))) { + if ((msr & MSR_PMC_FULL_WIDTH_BIT) && + (data & ~pmu->counter_bitmask[KVM_PMC_GP])) + return 1; + + if (!msr_info->host_initiated && + !(msr & MSR_PMC_FULL_WIDTH_BIT)) + data = (s64)(s32)data; + pmc_write_counter(pmc, data); + break; + } else if ((pmc = get_fixed_pmc(pmu, msr))) { + pmc_write_counter(pmc, data); + break; + } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) { + reserved_bits = pmu->reserved_bits; + if ((pmc->idx == 2) && + (pmu->raw_event_mask & HSW_IN_TX_CHECKPOINTED)) + reserved_bits ^= HSW_IN_TX_CHECKPOINTED; + if (data & reserved_bits) + return 1; + + if (data != pmc->eventsel) { + pmc->eventsel = data; + kvm_pmu_request_counter_reprogram(pmc); + } + break; + } else if (intel_pmu_handle_lbr_msrs_access(vcpu, msr_info, false)) { + break; + } + /* Not a known PMU MSR. */ + return 1; + } + + return 0; +} + +/* + * Map fixed counter events to architectural general purpose event encodings. + * Perf doesn't provide APIs to allow KVM to directly program a fixed counter, + * and so KVM instead programs the architectural event to effectively request + * the fixed counter. Perf isn't guaranteed to use a fixed counter and may + * instead program the encoding into a general purpose counter, e.g. if a + * different perf_event is already utilizing the requested counter, but the end + * result is the same (ignoring the fact that using a general purpose counter + * will likely exacerbate counter contention). + * + * Forcibly inlined to allow asserting on @index at build time, and there should + * never be more than one user. + */ +static __always_inline u64 intel_get_fixed_pmc_eventsel(unsigned int index) +{ + const enum perf_hw_id fixed_pmc_perf_ids[] = { + [0] = PERF_COUNT_HW_INSTRUCTIONS, + [1] = PERF_COUNT_HW_CPU_CYCLES, + [2] = PERF_COUNT_HW_REF_CPU_CYCLES, + }; + u64 eventsel; + + BUILD_BUG_ON(ARRAY_SIZE(fixed_pmc_perf_ids) != KVM_MAX_NR_INTEL_FIXED_COUNTERS); + BUILD_BUG_ON(index >= KVM_MAX_NR_INTEL_FIXED_COUNTERS); + + /* + * Yell if perf reports support for a fixed counter but perf doesn't + * have a known encoding for the associated general purpose event. + */ + eventsel = perf_get_hw_event_config(fixed_pmc_perf_ids[index]); + WARN_ON_ONCE(!eventsel && index < kvm_pmu_cap.num_counters_fixed); + return eventsel; +} + +static void intel_pmu_enable_fixed_counter_bits(struct kvm_pmu *pmu, u64 bits) +{ + int i; + + for (i = 0; i < pmu->nr_arch_fixed_counters; i++) + pmu->fixed_ctr_ctrl_rsvd &= ~intel_fixed_bits_by_idx(i, bits); +} + +static void intel_pmu_refresh(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + struct kvm_cpuid_entry2 *entry; + union cpuid10_eax eax; + union cpuid10_edx edx; + u64 perf_capabilities; + u64 counter_rsvd; + + if (!lbr_desc) + return; + + memset(&lbr_desc->records, 0, sizeof(lbr_desc->records)); + + /* + * Setting passthrough of LBR MSRs is done only in the VM-Entry loop, + * and PMU refresh is disallowed after the vCPU has run, i.e. this code + * should never be reached while KVM is passing through MSRs. + */ + if (KVM_BUG_ON(lbr_desc->msr_passthrough, vcpu->kvm)) + return; + + entry = kvm_find_cpuid_entry(vcpu, 0xa); + if (!entry) + return; + + eax.full = entry->eax; + edx.full = entry->edx; + + pmu->version = eax.split.version_id; + if (!pmu->version) + return; + + pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters, + kvm_pmu_cap.num_counters_gp); + eax.split.bit_width = min_t(int, eax.split.bit_width, + kvm_pmu_cap.bit_width_gp); + pmu->counter_bitmask[KVM_PMC_GP] = BIT_ULL(eax.split.bit_width) - 1; + eax.split.mask_length = min_t(int, eax.split.mask_length, + kvm_pmu_cap.events_mask_len); + pmu->available_event_types = ~entry->ebx & (BIT_ULL(eax.split.mask_length) - 1); + + entry = kvm_find_cpuid_entry_index(vcpu, 7, 0); + if (entry && + (boot_cpu_has(X86_FEATURE_HLE) || boot_cpu_has(X86_FEATURE_RTM)) && + (entry->ebx & (X86_FEATURE_HLE|X86_FEATURE_RTM))) { + pmu->reserved_bits ^= HSW_IN_TX; + pmu->raw_event_mask |= (HSW_IN_TX|HSW_IN_TX_CHECKPOINTED); + } + + perf_capabilities = vcpu_get_perf_capabilities(vcpu); + if (intel_pmu_lbr_is_compatible(vcpu) && + (perf_capabilities & PERF_CAP_LBR_FMT)) + memcpy(&lbr_desc->records, &vmx_lbr_caps, sizeof(vmx_lbr_caps)); + else + lbr_desc->records.nr = 0; + + if (lbr_desc->records.nr) + bitmap_set(pmu->all_valid_pmc_idx, INTEL_PMC_IDX_FIXED_VLBR, 1); + + if (pmu->version == 1) + return; + + pmu->nr_arch_fixed_counters = min_t(int, edx.split.num_counters_fixed, + kvm_pmu_cap.num_counters_fixed); + edx.split.bit_width_fixed = min_t(int, edx.split.bit_width_fixed, + kvm_pmu_cap.bit_width_fixed); + pmu->counter_bitmask[KVM_PMC_FIXED] = BIT_ULL(edx.split.bit_width_fixed) - 1; + + intel_pmu_enable_fixed_counter_bits(pmu, INTEL_FIXED_0_KERNEL | + INTEL_FIXED_0_USER | + INTEL_FIXED_0_ENABLE_PMI); + + counter_rsvd = ~((BIT_ULL(pmu->nr_arch_gp_counters) - 1) | + ((BIT_ULL(pmu->nr_arch_fixed_counters) - 1) << KVM_FIXED_PMC_BASE_IDX)); + pmu->global_ctrl_rsvd = counter_rsvd; + + /* + * 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_rsvd = pmu->global_ctrl_rsvd + & ~(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_status_rsvd &= + ~MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI; + + if (perf_capabilities & PERF_CAP_PEBS_FORMAT) { + if (perf_capabilities & PERF_CAP_PEBS_BASELINE) { + pmu->pebs_enable_rsvd = counter_rsvd; + pmu->reserved_bits &= ~ICL_EVENTSEL_ADAPTIVE; + pmu->pebs_data_cfg_rsvd = ~0xff00000full; + intel_pmu_enable_fixed_counter_bits(pmu, ICL_FIXED_0_ADAPTIVE); + } else { + pmu->pebs_enable_rsvd = ~(BIT_ULL(pmu->nr_arch_gp_counters) - 1); + } + } +} + +static void intel_pmu_init(struct kvm_vcpu *vcpu) +{ + int i; + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + + if (!lbr_desc) + return; + + for (i = 0; i < KVM_MAX_NR_INTEL_GP_COUNTERS; i++) { + pmu->gp_counters[i].type = KVM_PMC_GP; + pmu->gp_counters[i].vcpu = vcpu; + pmu->gp_counters[i].idx = i; + pmu->gp_counters[i].current_config = 0; + } + + for (i = 0; i < KVM_MAX_NR_INTEL_FIXED_COUNTERS; i++) { + pmu->fixed_counters[i].type = KVM_PMC_FIXED; + pmu->fixed_counters[i].vcpu = vcpu; + pmu->fixed_counters[i].idx = i + KVM_FIXED_PMC_BASE_IDX; + pmu->fixed_counters[i].current_config = 0; + pmu->fixed_counters[i].eventsel = intel_get_fixed_pmc_eventsel(i); + } + + lbr_desc->records.nr = 0; + lbr_desc->event = NULL; + lbr_desc->msr_passthrough = false; +} + +static void intel_pmu_reset(struct kvm_vcpu *vcpu) +{ + intel_pmu_release_guest_lbr_event(vcpu); +} + +/* + * Emulate LBR_On_PMI behavior for 1 < pmu.version < 4. + * + * If Freeze_LBR_On_PMI = 1, the LBR is frozen on PMI and + * the KVM emulates to clear the LBR bit (bit 0) in IA32_DEBUGCTL. + * + * Guest needs to re-enable LBR to resume branches recording. + */ +static void intel_pmu_legacy_freezing_lbrs_on_pmi(struct kvm_vcpu *vcpu) +{ + u64 data = vmx_guest_debugctl_read(); + + if (data & DEBUGCTLMSR_FREEZE_LBRS_ON_PMI) { + data &= ~DEBUGCTLMSR_LBR; + vmx_guest_debugctl_write(vcpu, data); + } +} + +static void intel_pmu_deliver_pmi(struct kvm_vcpu *vcpu) +{ + u8 version = vcpu_to_pmu(vcpu)->version; + + if (!intel_pmu_lbr_is_enabled(vcpu)) + return; + + if (version > 1 && version < 4) + intel_pmu_legacy_freezing_lbrs_on_pmi(vcpu); +} + +static void vmx_update_intercept_for_lbr_msrs(struct kvm_vcpu *vcpu, bool set) +{ + struct x86_pmu_lbr *lbr = vcpu_to_lbr_records(vcpu); + int i; + + for (i = 0; i < lbr->nr; i++) { + vmx_set_intercept_for_msr(vcpu, lbr->from + i, MSR_TYPE_RW, set); + vmx_set_intercept_for_msr(vcpu, lbr->to + i, MSR_TYPE_RW, set); + if (lbr->info) + vmx_set_intercept_for_msr(vcpu, lbr->info + i, MSR_TYPE_RW, set); + } + + vmx_set_intercept_for_msr(vcpu, MSR_LBR_SELECT, MSR_TYPE_RW, set); + vmx_set_intercept_for_msr(vcpu, MSR_LBR_TOS, MSR_TYPE_RW, set); +} + +static inline void vmx_disable_lbr_msrs_passthrough(struct kvm_vcpu *vcpu) +{ + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + + if (!lbr_desc->msr_passthrough) + return; + + vmx_update_intercept_for_lbr_msrs(vcpu, true); + lbr_desc->msr_passthrough = false; +} + +static inline void vmx_enable_lbr_msrs_passthrough(struct kvm_vcpu *vcpu) +{ + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + + if (lbr_desc->msr_passthrough) + return; + + vmx_update_intercept_for_lbr_msrs(vcpu, false); + lbr_desc->msr_passthrough = true; +} + +/* + * Higher priority host perf events (e.g. cpu pinned) could reclaim the + * pmu resources (e.g. LBR) that were assigned to the guest. This is + * usually done via ipi calls (more details in perf_install_in_context). + * + * Before entering the non-root mode (with irq disabled here), double + * confirm that the pmu features enabled to the guest are not reclaimed + * by higher priority host events. Otherwise, disallow vcpu's access to + * the reclaimed features. + */ +void vmx_passthrough_lbr_msrs(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + + if (WARN_ON_ONCE(!lbr_desc)) + return; + + if (!lbr_desc->event) { + vmx_disable_lbr_msrs_passthrough(vcpu); + if (vmx_guest_debugctl_read() & DEBUGCTLMSR_LBR) + goto warn; + if (test_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use)) + goto warn; + return; + } + + if (lbr_desc->event->state < PERF_EVENT_STATE_ACTIVE) { + vmx_disable_lbr_msrs_passthrough(vcpu); + __clear_bit(INTEL_PMC_IDX_FIXED_VLBR, pmu->pmc_in_use); + goto warn; + } else + vmx_enable_lbr_msrs_passthrough(vcpu); + + return; + +warn: + pr_warn_ratelimited("vcpu-%d: fail to passthrough LBR.\n", vcpu->vcpu_id); +} + +static void intel_pmu_cleanup(struct kvm_vcpu *vcpu) +{ + if (!(vmx_guest_debugctl_read() & DEBUGCTLMSR_LBR)) + intel_pmu_release_guest_lbr_event(vcpu); +} + +void intel_pmu_cross_mapped_check(struct kvm_pmu *pmu) +{ + struct kvm_pmc *pmc = NULL; + int bit, hw_idx; + + kvm_for_each_pmc(pmu, pmc, bit, (unsigned long *)&pmu->global_ctrl) { + if (!pmc_is_locally_enabled(pmc) || + !pmc_is_globally_enabled(pmc) || !pmc->perf_event) + continue; + + /* + * A negative index indicates the event isn't mapped to a + * physical counter in the host, e.g. due to contention. + */ + hw_idx = pmc->perf_event->hw.idx; + if (hw_idx != pmc->idx && hw_idx > -1) + pmu->host_cross_mapped_mask |= BIT_ULL(hw_idx); + } +} + +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, + .is_valid_msr = intel_is_valid_msr, + .get_msr = intel_pmu_get_msr, + .set_msr = intel_pmu_set_msr, + .refresh = intel_pmu_refresh, + .init = intel_pmu_init, + .reset = intel_pmu_reset, + .deliver_pmi = intel_pmu_deliver_pmi, + .cleanup = intel_pmu_cleanup, + .EVENTSEL_EVENT = ARCH_PERFMON_EVENTSEL_EVENT, + .MAX_NR_GP_COUNTERS = KVM_MAX_NR_INTEL_GP_COUNTERS, + .MIN_NR_GP_COUNTERS = 1, +}; |
