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Diffstat (limited to 'arch/x86/kvm/pmu.c')
| -rw-r--r-- | arch/x86/kvm/pmu.c | 1424 |
1 files changed, 1424 insertions, 0 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c new file mode 100644 index 000000000..dd1c57593 --- /dev/null +++ b/arch/x86/kvm/pmu.c @@ -0,0 +1,1424 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Kernel-based Virtual Machine -- Performance Monitoring Unit support + * + * Copyright 2015 Red Hat, Inc. and/or its affiliates. + * + * Authors: + * Avi Kivity <avi@redhat.com> + * Gleb Natapov <gleb@redhat.com> + * Wei Huang <wei@redhat.com> + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/types.h> +#include <linux/kvm_host.h> +#include <linux/perf_event.h> +#include <linux/bsearch.h> +#include <linux/sort.h> +#include <linux/moduleparam.h> +#include <asm/perf_event.h> +#include <asm/cpu_device_id.h> +#include "x86.h" +#include "cpuid.h" +#include "lapic.h" +#include "pmu.h" + +/* This is enough to filter the vast majority of currently defined events. */ +#define KVM_PMU_EVENT_FILTER_MAX_EVENTS 300 + +/* Unadultered PMU capabilities of the host, i.e. of hardware. */ +static struct x86_pmu_capability __read_mostly kvm_host_pmu; + +/* KVM's PMU capabilities, i.e. the intersection of KVM and hardware support. */ +struct x86_pmu_capability __read_mostly kvm_pmu_cap; +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_pmu_cap); + +/* Enable/disable PMU virtualization */ +bool __read_mostly enable_pmu = true; +EXPORT_SYMBOL_FOR_KVM_INTERNAL(enable_pmu); +module_param(enable_pmu, bool, 0444); + +/* Enable/disabled mediated PMU virtualization. */ +bool __read_mostly enable_mediated_pmu; +EXPORT_SYMBOL_FOR_KVM_INTERNAL(enable_mediated_pmu); + +struct kvm_pmu_emulated_event_selectors { + u64 INSTRUCTIONS_RETIRED; + u64 BRANCH_INSTRUCTIONS_RETIRED; +}; +static struct kvm_pmu_emulated_event_selectors __read_mostly kvm_pmu_eventsel; + +/* Precise Distribution of Instructions Retired (PDIR) */ +static const struct x86_cpu_id vmx_pebs_pdir_cpu[] = { + X86_MATCH_VFM(INTEL_ICELAKE_D, NULL), + X86_MATCH_VFM(INTEL_ICELAKE_X, NULL), + /* Instruction-Accurate PDIR (PDIR++) */ + X86_MATCH_VFM(INTEL_SAPPHIRERAPIDS_X, NULL), + {} +}; + +/* Precise Distribution (PDist) */ +static const struct x86_cpu_id vmx_pebs_pdist_cpu[] = { + X86_MATCH_VFM(INTEL_SAPPHIRERAPIDS_X, NULL), + {} +}; + +/* NOTE: + * - Each perf counter is defined as "struct kvm_pmc"; + * - There are two types of perf counters: general purpose (gp) and fixed. + * gp counters are stored in gp_counters[] and fixed counters are stored + * in fixed_counters[] respectively. Both of them are part of "struct + * kvm_pmu"; + * - pmu.c understands the difference between gp counters and fixed counters. + * However AMD doesn't support fixed-counters; + * - There are three types of index to access perf counters (PMC): + * 1. MSR (named msr): For example Intel has MSR_IA32_PERFCTRn and AMD + * has MSR_K7_PERFCTRn and, for families 15H and later, + * MSR_F15H_PERF_CTRn, where MSR_F15H_PERF_CTR[0-3] are + * aliased to MSR_K7_PERFCTRn. + * 2. MSR Index (named idx): This normally is used by RDPMC instruction. + * For instance AMD RDPMC instruction uses 0000_0003h in ECX to access + * C001_0007h (MSR_K7_PERCTR3). Intel has a similar mechanism, except + * that it also supports fixed counters. idx can be used to as index to + * gp and fixed counters. + * 3. Global PMC Index (named pmc): pmc is an index specific to PMU + * 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 .. KVM_MAX_NR_INTEL_GP_COUNTERS-1] <=> gp counters + * [KVM_FIXED_PMC_BASE_IDX .. KVM_FIXED_PMC_BASE_IDX + 2] <=> fixed + * * AMD: [0 .. AMD64_NUM_COUNTERS-1] and, for families 15H + * and later, [0 .. AMD64_NUM_COUNTERS_CORE-1] <=> gp counters + */ + +static struct kvm_pmu_ops kvm_pmu_ops __read_mostly; + +#define KVM_X86_PMU_OP(func) \ + DEFINE_STATIC_CALL_NULL(kvm_x86_pmu_##func, \ + *(((struct kvm_pmu_ops *)0)->func)); +#define KVM_X86_PMU_OP_OPTIONAL KVM_X86_PMU_OP +#define KVM_X86_PMU_OP_OPTIONAL_RET0 KVM_X86_PMU_OP +#include <asm/kvm-x86-pmu-ops.h> +EXPORT_STATIC_CALL_GPL(kvm_x86_pmu_pmc_is_disabled_in_current_mode); + +void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops) +{ + memcpy(&kvm_pmu_ops, pmu_ops, sizeof(kvm_pmu_ops)); + +#define __KVM_X86_PMU_OP(func) \ + static_call_update(kvm_x86_pmu_##func, kvm_pmu_ops.func); +#define KVM_X86_PMU_OP(func) \ + WARN_ON(!kvm_pmu_ops.func); __KVM_X86_PMU_OP(func) +#define KVM_X86_PMU_OP_OPTIONAL __KVM_X86_PMU_OP +#define KVM_X86_PMU_OP_OPTIONAL_RET0(func) \ + static_call_update(kvm_x86_pmu_##func, (void *)kvm_pmu_ops.func ? : \ + (void *)__static_call_return0); +#include <asm/kvm-x86-pmu-ops.h> +#undef __KVM_X86_PMU_OP +} + +void kvm_init_pmu_capability(struct kvm_pmu_ops *pmu_ops) +{ + bool is_intel = boot_cpu_data.x86_vendor == X86_VENDOR_INTEL; + int min_nr_gp_ctrs = pmu_ops->MIN_NR_GP_COUNTERS; + + /* + * Hybrid PMUs don't play nice with virtualization without careful + * configuration by userspace, and KVM's APIs for reporting supported + * vPMU features do not account for hybrid PMUs. Disable vPMU support + * for hybrid PMUs until KVM gains a way to let userspace opt-in. + */ + if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU)) { + enable_pmu = false; + memset(&kvm_host_pmu, 0, sizeof(kvm_host_pmu)); + } else { + perf_get_x86_pmu_capability(&kvm_host_pmu); + } + + if (enable_pmu) { + /* + * WARN if perf did NOT disable hardware PMU if the number of + * architecturally required GP counters aren't present, i.e. if + * there are a non-zero number of counters, but fewer than what + * is architecturally required. + */ + if (!kvm_host_pmu.num_counters_gp || + WARN_ON_ONCE(kvm_host_pmu.num_counters_gp < min_nr_gp_ctrs)) + enable_pmu = false; + else if (is_intel && !kvm_host_pmu.version) + enable_pmu = false; + } + + if (!enable_pmu || !enable_mediated_pmu || !kvm_host_pmu.mediated || + !pmu_ops->is_mediated_pmu_supported(&kvm_host_pmu)) + enable_mediated_pmu = false; + + if (!enable_mediated_pmu) + pmu_ops->write_global_ctrl = NULL; + + if (!enable_pmu) { + memset(&kvm_pmu_cap, 0, sizeof(kvm_pmu_cap)); + return; + } + + memcpy(&kvm_pmu_cap, &kvm_host_pmu, sizeof(kvm_host_pmu)); + kvm_pmu_cap.version = min(kvm_pmu_cap.version, 2); + kvm_pmu_cap.num_counters_gp = min(kvm_pmu_cap.num_counters_gp, + pmu_ops->MAX_NR_GP_COUNTERS); + kvm_pmu_cap.num_counters_fixed = min(kvm_pmu_cap.num_counters_fixed, + KVM_MAX_NR_FIXED_COUNTERS); + + kvm_pmu_eventsel.INSTRUCTIONS_RETIRED = + perf_get_hw_event_config(PERF_COUNT_HW_INSTRUCTIONS); + kvm_pmu_eventsel.BRANCH_INSTRUCTIONS_RETIRED = + perf_get_hw_event_config(PERF_COUNT_HW_BRANCH_INSTRUCTIONS); +} + +void kvm_handle_guest_mediated_pmi(void) +{ + struct kvm_vcpu *vcpu = kvm_get_running_vcpu(); + + if (WARN_ON_ONCE(!vcpu || !kvm_vcpu_has_mediated_pmu(vcpu))) + return; + + kvm_make_request(KVM_REQ_PMI, vcpu); +} + +static inline void __kvm_perf_overflow(struct kvm_pmc *pmc, bool in_pmi) +{ + struct kvm_pmu *pmu = pmc_to_pmu(pmc); + bool skip_pmi = false; + + if (pmc->perf_event && pmc->perf_event->attr.precise_ip) { + if (!in_pmi) { + /* + * TODO: KVM is currently _choosing_ to not generate records + * for emulated instructions, avoiding BUFFER_OVF PMI when + * there are no records. Strictly speaking, it should be done + * as well in the right context to improve sampling accuracy. + */ + skip_pmi = true; + } else { + /* Indicate PEBS overflow PMI to guest. */ + skip_pmi = __test_and_set_bit(GLOBAL_STATUS_BUFFER_OVF_BIT, + (unsigned long *)&pmu->global_status); + } + } else { + __set_bit(pmc->idx, (unsigned long *)&pmu->global_status); + } + + if (pmc->intr && !skip_pmi) + kvm_make_request(KVM_REQ_PMI, pmc->vcpu); +} + +static void kvm_perf_overflow(struct perf_event *perf_event, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct kvm_pmc *pmc = perf_event->overflow_handler_context; + + /* + * Ignore asynchronous overflow events for counters that are scheduled + * to be reprogrammed, e.g. if a PMI for the previous event races with + * KVM's handling of a related guest WRMSR. + */ + if (test_and_set_bit(pmc->idx, pmc_to_pmu(pmc)->reprogram_pmi)) + return; + + __kvm_perf_overflow(pmc, true); + + kvm_make_request(KVM_REQ_PMU, pmc->vcpu); +} + +static u64 pmc_get_pebs_precise_level(struct kvm_pmc *pmc) +{ + /* + * For some model specific pebs counters with special capabilities + * (PDIR, PDIR++, PDIST), KVM needs to raise the event precise + * level to the maximum value (currently 3, backwards compatible) + * so that the perf subsystem would assign specific hardware counter + * with that capability for vPMC. + */ + if ((pmc->idx == 0 && x86_match_cpu(vmx_pebs_pdist_cpu)) || + (pmc->idx == 32 && x86_match_cpu(vmx_pebs_pdir_cpu))) + return 3; + + /* + * The non-zero precision level of guest event makes the ordinary + * guest event becomes a guest PEBS event and triggers the host + * PEBS PMI handler to determine whether the PEBS overflow PMI + * comes from the host counters or the guest. + */ + return 1; +} + +static u64 get_sample_period(struct kvm_pmc *pmc, u64 counter_value) +{ + u64 sample_period = (-counter_value) & pmc_bitmask(pmc); + + if (!sample_period) + sample_period = pmc_bitmask(pmc) + 1; + return sample_period; +} + +static int pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, u64 config, + bool exclude_user, bool exclude_kernel, + bool intr) +{ + struct kvm_pmu *pmu = pmc_to_pmu(pmc); + struct perf_event *event; + struct perf_event_attr attr = { + .type = type, + .size = sizeof(attr), + .pinned = true, + .exclude_idle = true, + .exclude_host = 1, + .exclude_user = exclude_user, + .exclude_kernel = exclude_kernel, + .config = config, + }; + bool pebs = test_bit(pmc->idx, (unsigned long *)&pmu->pebs_enable); + + attr.sample_period = get_sample_period(pmc, pmc->counter); + + if ((attr.config & HSW_IN_TX_CHECKPOINTED) && + (boot_cpu_has(X86_FEATURE_RTM) || boot_cpu_has(X86_FEATURE_HLE))) { + /* + * HSW_IN_TX_CHECKPOINTED is not supported with nonzero + * period. Just clear the sample period so at least + * allocating the counter doesn't fail. + */ + attr.sample_period = 0; + } + if (pebs) { + /* + * For most PEBS hardware events, the difference in the software + * precision levels of guest and host PEBS events will not affect + * the accuracy of the PEBS profiling result, because the "event IP" + * in the PEBS record is calibrated on the guest side. + */ + attr.precise_ip = pmc_get_pebs_precise_level(pmc); + } + + event = perf_event_create_kernel_counter(&attr, -1, current, + kvm_perf_overflow, pmc); + if (IS_ERR(event)) { + pr_debug_ratelimited("kvm_pmu: event creation failed %ld for pmc->idx = %d\n", + PTR_ERR(event), pmc->idx); + return PTR_ERR(event); + } + + pmc->perf_event = event; + pmc_to_pmu(pmc)->event_count++; + pmc->is_paused = false; + pmc->intr = intr || pebs; + return 0; +} + +static bool pmc_pause_counter(struct kvm_pmc *pmc) +{ + u64 counter = pmc->counter; + u64 prev_counter; + + /* update counter, reset event value to avoid redundant accumulation */ + if (pmc->perf_event && !pmc->is_paused) + counter += perf_event_pause(pmc->perf_event, true); + + /* + * Snapshot the previous counter *after* accumulating state from perf. + * If overflow already happened, hardware (via perf) is responsible for + * generating a PMI. KVM just needs to detect overflow on emulated + * counter events that haven't yet been processed. + */ + prev_counter = counter & pmc_bitmask(pmc); + + counter += pmc->emulated_counter; + pmc->counter = counter & pmc_bitmask(pmc); + + pmc->emulated_counter = 0; + pmc->is_paused = true; + + return pmc->counter < prev_counter; +} + +static bool pmc_resume_counter(struct kvm_pmc *pmc) +{ + if (!pmc->perf_event) + return false; + + /* recalibrate sample period and check if it's accepted by perf core */ + if (is_sampling_event(pmc->perf_event) && + perf_event_period(pmc->perf_event, + get_sample_period(pmc, pmc->counter))) + return false; + + if (test_bit(pmc->idx, (unsigned long *)&pmc_to_pmu(pmc)->pebs_enable) != + (!!pmc->perf_event->attr.precise_ip)) + return false; + + /* reuse perf_event to serve as pmc_reprogram_counter() does*/ + perf_event_enable(pmc->perf_event); + pmc->is_paused = false; + + return true; +} + +static void pmc_release_perf_event(struct kvm_pmc *pmc) +{ + if (pmc->perf_event) { + perf_event_release_kernel(pmc->perf_event); + pmc->perf_event = NULL; + pmc->current_config = 0; + pmc_to_pmu(pmc)->event_count--; + } +} + +static void pmc_stop_counter(struct kvm_pmc *pmc) +{ + if (pmc->perf_event) { + pmc->counter = pmc_read_counter(pmc); + pmc_release_perf_event(pmc); + } +} + +static void pmc_update_sample_period(struct kvm_pmc *pmc) +{ + if (!pmc->perf_event || pmc->is_paused || + !is_sampling_event(pmc->perf_event)) + return; + + perf_event_period(pmc->perf_event, + get_sample_period(pmc, pmc->counter)); +} + +void pmc_write_counter(struct kvm_pmc *pmc, u64 val) +{ + if (kvm_vcpu_has_mediated_pmu(pmc->vcpu)) { + pmc->counter = val & pmc_bitmask(pmc); + return; + } + + /* + * Drop any unconsumed accumulated counts, the WRMSR is a write, not a + * read-modify-write. Adjust the counter value so that its value is + * relative to the current count, as reading the current count from + * perf is faster than pausing and repgrogramming the event in order to + * reset it to '0'. Note, this very sneakily offsets the accumulated + * emulated count too, by using pmc_read_counter()! + */ + pmc->emulated_counter = 0; + pmc->counter += val - pmc_read_counter(pmc); + pmc->counter &= pmc_bitmask(pmc); + pmc_update_sample_period(pmc); +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(pmc_write_counter); + +static int filter_cmp(const void *pa, const void *pb, u64 mask) +{ + u64 a = *(u64 *)pa & mask; + u64 b = *(u64 *)pb & mask; + + return (a > b) - (a < b); +} + + +static int filter_sort_cmp(const void *pa, const void *pb) +{ + return filter_cmp(pa, pb, (KVM_PMU_MASKED_ENTRY_EVENT_SELECT | + KVM_PMU_MASKED_ENTRY_EXCLUDE)); +} + +/* + * For the event filter, searching is done on the 'includes' list and + * 'excludes' list separately rather than on the 'events' list (which + * has both). As a result the exclude bit can be ignored. + */ +static int filter_event_cmp(const void *pa, const void *pb) +{ + return filter_cmp(pa, pb, (KVM_PMU_MASKED_ENTRY_EVENT_SELECT)); +} + +static int find_filter_index(u64 *events, u64 nevents, u64 key) +{ + u64 *fe = bsearch(&key, events, nevents, sizeof(events[0]), + filter_event_cmp); + + if (!fe) + return -1; + + return fe - events; +} + +static bool is_filter_entry_match(u64 filter_event, u64 umask) +{ + u64 mask = filter_event >> (KVM_PMU_MASKED_ENTRY_UMASK_MASK_SHIFT - 8); + u64 match = filter_event & KVM_PMU_MASKED_ENTRY_UMASK_MATCH; + + BUILD_BUG_ON((KVM_PMU_ENCODE_MASKED_ENTRY(0, 0xff, 0, false) >> + (KVM_PMU_MASKED_ENTRY_UMASK_MASK_SHIFT - 8)) != + ARCH_PERFMON_EVENTSEL_UMASK); + + return (umask & mask) == match; +} + +static bool filter_contains_match(u64 *events, u64 nevents, u64 eventsel) +{ + u64 event_select = eventsel & kvm_pmu_ops.EVENTSEL_EVENT; + u64 umask = eventsel & ARCH_PERFMON_EVENTSEL_UMASK; + int i, index; + + index = find_filter_index(events, nevents, event_select); + if (index < 0) + return false; + + /* + * Entries are sorted by the event select. Walk the list in both + * directions to process all entries with the targeted event select. + */ + for (i = index; i < nevents; i++) { + if (filter_event_cmp(&events[i], &event_select)) + break; + + if (is_filter_entry_match(events[i], umask)) + return true; + } + + for (i = index - 1; i >= 0; i--) { + if (filter_event_cmp(&events[i], &event_select)) + break; + + if (is_filter_entry_match(events[i], umask)) + return true; + } + + return false; +} + +static bool is_gp_event_allowed(struct kvm_x86_pmu_event_filter *f, + u64 eventsel) +{ + if (filter_contains_match(f->includes, f->nr_includes, eventsel) && + !filter_contains_match(f->excludes, f->nr_excludes, eventsel)) + return f->action == KVM_PMU_EVENT_ALLOW; + + return f->action == KVM_PMU_EVENT_DENY; +} + +static bool is_fixed_event_allowed(struct kvm_x86_pmu_event_filter *filter, + int idx) +{ + int fixed_idx = idx - KVM_FIXED_PMC_BASE_IDX; + + if (filter->action == KVM_PMU_EVENT_DENY && + test_bit(fixed_idx, (ulong *)&filter->fixed_counter_bitmap)) + return false; + if (filter->action == KVM_PMU_EVENT_ALLOW && + !test_bit(fixed_idx, (ulong *)&filter->fixed_counter_bitmap)) + return false; + + return true; +} + +static bool pmc_is_event_allowed(struct kvm_pmc *pmc) +{ + struct kvm_x86_pmu_event_filter *filter; + struct kvm *kvm = pmc->vcpu->kvm; + + filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu); + if (!filter) + return true; + + if (pmc_is_gp(pmc)) + return is_gp_event_allowed(filter, pmc->eventsel); + + return is_fixed_event_allowed(filter, pmc->idx); +} + +static void kvm_mediated_pmu_refresh_event_filter(struct kvm_pmc *pmc) +{ + bool allowed = pmc_is_locally_enabled(pmc) && pmc_is_event_allowed(pmc); + struct kvm_pmu *pmu = pmc_to_pmu(pmc); + + if (pmc_is_gp(pmc)) { + pmc->eventsel_hw &= ~ARCH_PERFMON_EVENTSEL_ENABLE; + if (allowed) + pmc->eventsel_hw |= pmc->eventsel & + ARCH_PERFMON_EVENTSEL_ENABLE; + } else { + u64 mask = intel_fixed_bits_by_idx(pmc->idx - KVM_FIXED_PMC_BASE_IDX, 0xf); + + pmu->fixed_ctr_ctrl_hw &= ~mask; + if (allowed) + pmu->fixed_ctr_ctrl_hw |= pmu->fixed_ctr_ctrl & mask; + } +} + +static int reprogram_counter(struct kvm_pmc *pmc) +{ + struct kvm_pmu *pmu = pmc_to_pmu(pmc); + u64 eventsel = pmc->eventsel; + u64 new_config = eventsel; + bool emulate_overflow; + u8 fixed_ctr_ctrl; + + if (kvm_vcpu_has_mediated_pmu(pmu_to_vcpu(pmu))) { + kvm_mediated_pmu_refresh_event_filter(pmc); + return 0; + } + + emulate_overflow = pmc_pause_counter(pmc); + + if (!pmc_is_globally_enabled(pmc) || !pmc_is_locally_enabled(pmc) || + !pmc_is_event_allowed(pmc)) + return 0; + + if (emulate_overflow) + __kvm_perf_overflow(pmc, false); + + if (eventsel & ARCH_PERFMON_EVENTSEL_PIN_CONTROL) + printk_once("kvm pmu: pin control bit is ignored\n"); + + if (pmc_is_fixed(pmc)) { + fixed_ctr_ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, + pmc->idx - KVM_FIXED_PMC_BASE_IDX); + if (fixed_ctr_ctrl & INTEL_FIXED_0_KERNEL) + eventsel |= ARCH_PERFMON_EVENTSEL_OS; + if (fixed_ctr_ctrl & INTEL_FIXED_0_USER) + eventsel |= ARCH_PERFMON_EVENTSEL_USR; + if (fixed_ctr_ctrl & INTEL_FIXED_0_ENABLE_PMI) + eventsel |= ARCH_PERFMON_EVENTSEL_INT; + new_config = (u64)fixed_ctr_ctrl; + } + + if (pmc->current_config == new_config && pmc_resume_counter(pmc)) + return 0; + + pmc_release_perf_event(pmc); + + pmc->current_config = new_config; + + return pmc_reprogram_counter(pmc, PERF_TYPE_RAW, + (eventsel & pmu->raw_event_mask), + !(eventsel & ARCH_PERFMON_EVENTSEL_USR), + !(eventsel & ARCH_PERFMON_EVENTSEL_OS), + eventsel & ARCH_PERFMON_EVENTSEL_INT); +} + +static bool pmc_is_event_match(struct kvm_pmc *pmc, u64 eventsel) +{ + /* + * Ignore checks for edge detect (all events currently emulated by KVM + * are always rising edges), pin control (unsupported by modern CPUs), + * and counter mask and its invert flag (KVM doesn't emulate multiple + * events in a single clock cycle). + * + * Note, the uppermost nibble of AMD's mask overlaps Intel's IN_TX (bit + * 32) and IN_TXCP (bit 33), as well as two reserved bits (bits 35:34). + * Checking the "in HLE/RTM transaction" flags is correct as the vCPU + * can't be in a transaction if KVM is emulating an instruction. + * + * Checking the reserved bits might be wrong if they are defined in the + * future, but so could ignoring them, so do the simple thing for now. + */ + return !((pmc->eventsel ^ eventsel) & AMD64_RAW_EVENT_MASK_NB); +} + +void kvm_pmu_recalc_pmc_emulation(struct kvm_pmu *pmu, struct kvm_pmc *pmc) +{ + bitmap_clear(pmu->pmc_counting_instructions, pmc->idx, 1); + bitmap_clear(pmu->pmc_counting_branches, pmc->idx, 1); + + /* + * Do NOT consult the PMU event filters, as the filters must be checked + * at the time of emulation to ensure KVM uses fresh information, e.g. + * omitting a PMC from a bitmap could result in a missed event if the + * filter is changed to allow counting the event. + */ + if (!pmc_is_locally_enabled(pmc)) + return; + + if (pmc_is_event_match(pmc, kvm_pmu_eventsel.INSTRUCTIONS_RETIRED)) + bitmap_set(pmu->pmc_counting_instructions, pmc->idx, 1); + + if (pmc_is_event_match(pmc, kvm_pmu_eventsel.BRANCH_INSTRUCTIONS_RETIRED)) + bitmap_set(pmu->pmc_counting_branches, pmc->idx, 1); +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_pmu_recalc_pmc_emulation); + +void kvm_pmu_handle_event(struct kvm_vcpu *vcpu) +{ + DECLARE_BITMAP(bitmap, X86_PMC_IDX_MAX); + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + int bit; + + bitmap_copy(bitmap, pmu->reprogram_pmi, X86_PMC_IDX_MAX); + + /* + * The reprogramming bitmap can be written asynchronously by something + * other than the task that holds vcpu->mutex, take care to clear only + * the bits that will actually processed. + */ + BUILD_BUG_ON(sizeof(bitmap) != sizeof(atomic64_t)); + atomic64_andnot(*(s64 *)bitmap, &pmu->__reprogram_pmi); + + kvm_for_each_pmc(pmu, pmc, bit, bitmap) { + /* + * If reprogramming fails, e.g. due to contention, re-set the + * regprogram bit set, i.e. opportunistically try again on the + * next PMU refresh. Don't make a new request as doing so can + * stall the guest if reprogramming repeatedly fails. + */ + if (reprogram_counter(pmc)) + set_bit(pmc->idx, pmu->reprogram_pmi); + } + + /* + * Release unused perf_events if the corresponding guest MSRs weren't + * accessed during the last vCPU time slice (need_cleanup is set when + * the vCPU is scheduled back in). + */ + if (unlikely(pmu->need_cleanup)) + kvm_pmu_cleanup(vcpu); + + kvm_for_each_pmc(pmu, pmc, bit, bitmap) + kvm_pmu_recalc_pmc_emulation(pmu, pmc); +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_pmu_handle_event); + +int kvm_pmu_check_rdpmc_early(struct kvm_vcpu *vcpu, unsigned int idx) +{ + /* + * On Intel, VMX interception has priority over RDPMC exceptions that + * aren't already handled by the emulator, i.e. there are no additional + * check needed for Intel PMUs. + * + * On AMD, _all_ exceptions on RDPMC have priority over SVM intercepts, + * i.e. an invalid PMC results in a #GP, not #VMEXIT. + */ + if (!kvm_pmu_ops.check_rdpmc_early) + return 0; + + return kvm_pmu_call(check_rdpmc_early)(vcpu, idx); +} + +bool is_vmware_backdoor_pmc(u32 pmc_idx) +{ + switch (pmc_idx) { + case VMWARE_BACKDOOR_PMC_HOST_TSC: + case VMWARE_BACKDOOR_PMC_REAL_TIME: + case VMWARE_BACKDOOR_PMC_APPARENT_TIME: + return true; + } + return false; +} + +static int kvm_pmu_rdpmc_vmware(struct kvm_vcpu *vcpu, unsigned idx, u64 *data) +{ + u64 ctr_val; + + switch (idx) { + case VMWARE_BACKDOOR_PMC_HOST_TSC: + ctr_val = rdtsc(); + break; + case VMWARE_BACKDOOR_PMC_REAL_TIME: + ctr_val = ktime_get_boottime_ns(); + break; + case VMWARE_BACKDOOR_PMC_APPARENT_TIME: + ctr_val = ktime_get_boottime_ns() + + vcpu->kvm->arch.kvmclock_offset; + break; + default: + return 1; + } + + *data = ctr_val; + return 0; +} + +int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + u64 mask = ~0ull; + + if (!pmu->version) + return 1; + + if (is_vmware_backdoor_pmc(idx)) + return kvm_pmu_rdpmc_vmware(vcpu, idx, data); + + pmc = kvm_pmu_call(rdpmc_ecx_to_pmc)(vcpu, idx, &mask); + if (!pmc) + return 1; + + if (!kvm_is_cr4_bit_set(vcpu, X86_CR4_PCE) && + (kvm_x86_call(get_cpl)(vcpu) != 0) && + kvm_is_cr0_bit_set(vcpu, X86_CR0_PE)) + return 1; + + *data = pmc_read_counter(pmc) & mask; + return 0; +} + +static bool kvm_need_any_pmc_intercept(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + + if (!kvm_vcpu_has_mediated_pmu(vcpu)) + return true; + + /* + * Note! Check *host* PMU capabilities, not KVM's PMU capabilities, as + * KVM's capabilities are constrained based on KVM support, i.e. KVM's + * capabilities themselves may be a subset of hardware capabilities. + */ + return pmu->nr_arch_gp_counters != kvm_host_pmu.num_counters_gp || + pmu->nr_arch_fixed_counters != kvm_host_pmu.num_counters_fixed; +} + +bool kvm_need_perf_global_ctrl_intercept(struct kvm_vcpu *vcpu) +{ + return kvm_need_any_pmc_intercept(vcpu) || + !kvm_pmu_has_perf_global_ctrl(vcpu_to_pmu(vcpu)); +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_need_perf_global_ctrl_intercept); + +bool kvm_need_rdpmc_intercept(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + + /* + * VMware allows access to these Pseduo-PMCs even when read via RDPMC + * in Ring3 when CR4.PCE=0. + */ + if (enable_vmware_backdoor) + return true; + + return kvm_need_any_pmc_intercept(vcpu) || + pmu->counter_bitmask[KVM_PMC_GP] != (BIT_ULL(kvm_host_pmu.bit_width_gp) - 1) || + pmu->counter_bitmask[KVM_PMC_FIXED] != (BIT_ULL(kvm_host_pmu.bit_width_fixed) - 1); +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_need_rdpmc_intercept); + +void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu) +{ + if (lapic_in_kernel(vcpu)) { + kvm_pmu_call(deliver_pmi)(vcpu); + kvm_apic_local_deliver(vcpu->arch.apic, APIC_LVTPC); + } +} + +bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr) +{ + switch (msr) { + case MSR_CORE_PERF_GLOBAL_STATUS: + case MSR_CORE_PERF_GLOBAL_CTRL: + case MSR_CORE_PERF_GLOBAL_OVF_CTRL: + return kvm_pmu_has_perf_global_ctrl(vcpu_to_pmu(vcpu)); + default: + break; + } + return kvm_pmu_call(msr_idx_to_pmc)(vcpu, msr) || + kvm_pmu_call(is_valid_msr)(vcpu, msr); +} + +static void kvm_pmu_mark_pmc_in_use(struct kvm_vcpu *vcpu, u32 msr) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc = kvm_pmu_call(msr_idx_to_pmc)(vcpu, msr); + + if (pmc) + __set_bit(pmc->idx, pmu->pmc_in_use); +} + +int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + u32 msr = msr_info->index; + + switch (msr) { + case MSR_CORE_PERF_GLOBAL_STATUS: + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS: + msr_info->data = pmu->global_status; + break; + case MSR_AMD64_PERF_CNTR_GLOBAL_CTL: + case MSR_CORE_PERF_GLOBAL_CTRL: + msr_info->data = pmu->global_ctrl; + break; + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR: + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET: + case MSR_CORE_PERF_GLOBAL_OVF_CTRL: + msr_info->data = 0; + break; + default: + return kvm_pmu_call(get_msr)(vcpu, msr_info); + } + + return 0; +} + +int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + u32 msr = msr_info->index; + u64 data = msr_info->data; + u64 diff; + + /* + * Note, AMD ignores writes to reserved bits and read-only PMU MSRs, + * whereas Intel generates #GP on attempts to write reserved/RO MSRs. + */ + switch (msr) { + case MSR_CORE_PERF_GLOBAL_STATUS: + if (!msr_info->host_initiated) + return 1; /* RO MSR */ + fallthrough; + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS: + /* Per PPR, Read-only MSR. Writes are ignored. */ + if (!msr_info->host_initiated) + break; + + if (data & pmu->global_status_rsvd) + return 1; + + pmu->global_status = data; + break; + case MSR_AMD64_PERF_CNTR_GLOBAL_CTL: + data &= ~pmu->global_ctrl_rsvd; + fallthrough; + case MSR_CORE_PERF_GLOBAL_CTRL: + if (!kvm_valid_perf_global_ctrl(pmu, data)) + return 1; + + if (pmu->global_ctrl != data) { + diff = pmu->global_ctrl ^ data; + pmu->global_ctrl = data; + kvm_pmu_request_counters_reprogram(pmu, diff); + } + /* + * Unconditionally forward writes to vendor code, i.e. to the + * VMC{B,S}, as pmu->global_ctrl is per-VCPU, not per-VMC{B,S}. + */ + if (kvm_vcpu_has_mediated_pmu(vcpu)) + kvm_pmu_call(write_global_ctrl)(data); + break; + case MSR_CORE_PERF_GLOBAL_OVF_CTRL: + /* + * GLOBAL_OVF_CTRL, a.k.a. GLOBAL STATUS_RESET, clears bits in + * GLOBAL_STATUS, and so the set of reserved bits is the same. + */ + if (data & pmu->global_status_rsvd) + return 1; + fallthrough; + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR: + if (!msr_info->host_initiated) + pmu->global_status &= ~data; + break; + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET: + if (!msr_info->host_initiated) + pmu->global_status |= data & ~pmu->global_status_rsvd; + break; + default: + kvm_pmu_mark_pmc_in_use(vcpu, msr_info->index); + return kvm_pmu_call(set_msr)(vcpu, msr_info); + } + + return 0; +} + +static void kvm_pmu_reset(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + int i; + + pmu->need_cleanup = false; + + bitmap_zero(pmu->reprogram_pmi, X86_PMC_IDX_MAX); + bitmap_zero(pmu->pmc_has_mode_specific_enables, X86_PMC_IDX_MAX); + + kvm_for_each_pmc(pmu, pmc, i, pmu->all_valid_pmc_idx) { + pmc_stop_counter(pmc); + pmc->counter = 0; + pmc->emulated_counter = 0; + + if (pmc_is_gp(pmc)) { + pmc->eventsel = 0; + pmc->eventsel_hw = 0; + } + } + + pmu->fixed_ctr_ctrl = pmu->fixed_ctr_ctrl_hw = 0; + pmu->global_ctrl = pmu->global_status = 0; + + kvm_pmu_call(reset)(vcpu); +} + + +/* + * Refresh the PMU configuration for the vCPU, e.g. if userspace changes CPUID + * and/or PERF_CAPABILITIES. + */ +void kvm_pmu_refresh(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + + if (KVM_BUG_ON(!kvm_can_set_cpuid_and_feature_msrs(vcpu), vcpu->kvm)) + return; + + /* + * Stop/release all existing counters/events before realizing the new + * vPMU model. + */ + kvm_pmu_reset(vcpu); + + pmu->version = 0; + pmu->nr_arch_gp_counters = 0; + pmu->nr_arch_fixed_counters = 0; + pmu->counter_bitmask[KVM_PMC_GP] = 0; + pmu->counter_bitmask[KVM_PMC_FIXED] = 0; + pmu->reserved_bits = 0xffffffff00200000ull; + pmu->raw_event_mask = X86_RAW_EVENT_MASK; + pmu->global_ctrl_rsvd = ~0ull; + pmu->global_status_rsvd = ~0ull; + pmu->fixed_ctr_ctrl_rsvd = ~0ull; + pmu->pebs_enable_rsvd = ~0ull; + pmu->pebs_data_cfg_rsvd = ~0ull; + bitmap_zero(pmu->all_valid_pmc_idx, X86_PMC_IDX_MAX); + + if (!vcpu->kvm->arch.enable_pmu) + return; + + kvm_pmu_call(refresh)(vcpu); + + /* + * At RESET, both Intel and AMD CPUs set all enable bits for general + * purpose counters in IA32_PERF_GLOBAL_CTRL (so that software that + * was written for v1 PMUs don't unknowingly leave GP counters disabled + * in the global controls). Emulate that behavior when refreshing the + * PMU so that userspace doesn't need to manually set PERF_GLOBAL_CTRL. + */ + if (pmu->nr_arch_gp_counters && + (kvm_pmu_has_perf_global_ctrl(pmu) || kvm_vcpu_has_mediated_pmu(vcpu))) + pmu->global_ctrl = GENMASK_ULL(pmu->nr_arch_gp_counters - 1, 0); + + if (kvm_vcpu_has_mediated_pmu(vcpu)) + kvm_pmu_call(write_global_ctrl)(pmu->global_ctrl); + + bitmap_set(pmu->all_valid_pmc_idx, 0, pmu->nr_arch_gp_counters); + bitmap_set(pmu->all_valid_pmc_idx, KVM_FIXED_PMC_BASE_IDX, + pmu->nr_arch_fixed_counters); +} + +void kvm_pmu_init(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + + memset(pmu, 0, sizeof(*pmu)); + kvm_pmu_call(init)(vcpu); +} + +/* Release perf_events for vPMCs that have been unused for a full time slice. */ +void kvm_pmu_cleanup(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc = NULL; + DECLARE_BITMAP(bitmask, X86_PMC_IDX_MAX); + int i; + + pmu->need_cleanup = false; + + bitmap_andnot(bitmask, pmu->all_valid_pmc_idx, + pmu->pmc_in_use, X86_PMC_IDX_MAX); + + kvm_for_each_pmc(pmu, pmc, i, bitmask) { + if (pmc->perf_event && !pmc_is_locally_enabled(pmc)) + pmc_stop_counter(pmc); + } + + kvm_pmu_call(cleanup)(vcpu); + + bitmap_zero(pmu->pmc_in_use, X86_PMC_IDX_MAX); +} + +void kvm_pmu_destroy(struct kvm_vcpu *vcpu) +{ + kvm_pmu_reset(vcpu); +} + +static bool pmc_is_pmi_enabled(struct kvm_pmc *pmc) +{ + u8 fixed_ctr_ctrl; + + if (pmc_is_gp(pmc)) + return pmc->eventsel & ARCH_PERFMON_EVENTSEL_INT; + + fixed_ctr_ctrl = fixed_ctrl_field(pmc_to_pmu(pmc)->fixed_ctr_ctrl, + pmc->idx - KVM_FIXED_PMC_BASE_IDX); + return fixed_ctr_ctrl & INTEL_FIXED_0_ENABLE_PMI; +} + +static void kvm_pmu_incr_counter(struct kvm_pmc *pmc) +{ + struct kvm_vcpu *vcpu = pmc->vcpu; + + /* + * For perf-based PMUs, accumulate software-emulated events separately + * from pmc->counter, as pmc->counter is offset by the count of the + * associated perf event. Request reprogramming, which will consult + * both emulated and hardware-generated events to detect overflow. + */ + if (!kvm_vcpu_has_mediated_pmu(vcpu)) { + pmc->emulated_counter++; + kvm_pmu_request_counter_reprogram(pmc); + return; + } + + /* + * For mediated PMUs, pmc->counter is updated when the vCPU's PMU is + * put, and will be loaded into hardware when the PMU is loaded. Simply + * increment the counter and signal overflow if it wraps to zero. + */ + pmc->counter = (pmc->counter + 1) & pmc_bitmask(pmc); + if (!pmc->counter) { + pmc_to_pmu(pmc)->global_status |= BIT_ULL(pmc->idx); + if (pmc_is_pmi_enabled(pmc)) + kvm_make_request(KVM_REQ_PMI, vcpu); + } +} + +static inline bool cpl_is_matched(struct kvm_pmc *pmc) +{ + bool select_os, select_user; + u64 config; + + if (pmc_is_gp(pmc)) { + config = pmc->eventsel; + select_os = config & ARCH_PERFMON_EVENTSEL_OS; + select_user = config & ARCH_PERFMON_EVENTSEL_USR; + } else { + config = fixed_ctrl_field(pmc_to_pmu(pmc)->fixed_ctr_ctrl, + pmc->idx - KVM_FIXED_PMC_BASE_IDX); + select_os = config & INTEL_FIXED_0_KERNEL; + select_user = config & INTEL_FIXED_0_USER; + } + + /* + * Skip the CPL lookup, which isn't free on Intel, if the result will + * be the same regardless of the CPL. + */ + if (select_os == select_user) + return select_os; + + return (kvm_x86_call(get_cpl)(pmc->vcpu) == 0) ? select_os : + select_user; +} + +static void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, + const unsigned long *event_pmcs) +{ + DECLARE_BITMAP(bitmap, X86_PMC_IDX_MAX); + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + int i, idx; + + BUILD_BUG_ON(sizeof(pmu->global_ctrl) * BITS_PER_BYTE != X86_PMC_IDX_MAX); + + if (bitmap_empty(event_pmcs, X86_PMC_IDX_MAX)) + return; + + if (!kvm_pmu_has_perf_global_ctrl(pmu)) + bitmap_copy(bitmap, event_pmcs, X86_PMC_IDX_MAX); + else if (!bitmap_and(bitmap, event_pmcs, + (unsigned long *)&pmu->global_ctrl, X86_PMC_IDX_MAX)) + return; + + idx = srcu_read_lock(&vcpu->kvm->srcu); + kvm_for_each_pmc(pmu, pmc, i, bitmap) { + if (!pmc_is_event_allowed(pmc) || !cpl_is_matched(pmc)) + continue; + + kvm_pmu_incr_counter(pmc); + } + srcu_read_unlock(&vcpu->kvm->srcu, idx); +} + +void kvm_pmu_instruction_retired(struct kvm_vcpu *vcpu) +{ + kvm_pmu_trigger_event(vcpu, vcpu_to_pmu(vcpu)->pmc_counting_instructions); +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_pmu_instruction_retired); + +void kvm_pmu_branch_retired(struct kvm_vcpu *vcpu) +{ + kvm_pmu_trigger_event(vcpu, vcpu_to_pmu(vcpu)->pmc_counting_branches); +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_pmu_branch_retired); + +static bool is_masked_filter_valid(const struct kvm_x86_pmu_event_filter *filter) +{ + u64 mask = kvm_pmu_ops.EVENTSEL_EVENT | + KVM_PMU_MASKED_ENTRY_UMASK_MASK | + KVM_PMU_MASKED_ENTRY_UMASK_MATCH | + KVM_PMU_MASKED_ENTRY_EXCLUDE; + int i; + + for (i = 0; i < filter->nevents; i++) { + if (filter->events[i] & ~mask) + return false; + } + + return true; +} + +static void convert_to_masked_filter(struct kvm_x86_pmu_event_filter *filter) +{ + int i, j; + + for (i = 0, j = 0; i < filter->nevents; i++) { + /* + * Skip events that are impossible to match against a guest + * event. When filtering, only the event select + unit mask + * of the guest event is used. To maintain backwards + * compatibility, impossible filters can't be rejected :-( + */ + if (filter->events[i] & ~(kvm_pmu_ops.EVENTSEL_EVENT | + ARCH_PERFMON_EVENTSEL_UMASK)) + continue; + /* + * Convert userspace events to a common in-kernel event so + * only one code path is needed to support both events. For + * the in-kernel events use masked events because they are + * flexible enough to handle both cases. To convert to masked + * events all that's needed is to add an "all ones" umask_mask, + * (unmasked filter events don't support EXCLUDE). + */ + filter->events[j++] = filter->events[i] | + (0xFFULL << KVM_PMU_MASKED_ENTRY_UMASK_MASK_SHIFT); + } + + filter->nevents = j; +} + +static int prepare_filter_lists(struct kvm_x86_pmu_event_filter *filter) +{ + int i; + + if (!(filter->flags & KVM_PMU_EVENT_FLAG_MASKED_EVENTS)) + convert_to_masked_filter(filter); + else if (!is_masked_filter_valid(filter)) + return -EINVAL; + + /* + * Sort entries by event select and includes vs. excludes so that all + * entries for a given event select can be processed efficiently during + * filtering. The EXCLUDE flag uses a more significant bit than the + * event select, and so the sorted list is also effectively split into + * includes and excludes sub-lists. + */ + sort(&filter->events, filter->nevents, sizeof(filter->events[0]), + filter_sort_cmp, NULL); + + i = filter->nevents; + /* Find the first EXCLUDE event (only supported for masked events). */ + if (filter->flags & KVM_PMU_EVENT_FLAG_MASKED_EVENTS) { + for (i = 0; i < filter->nevents; i++) { + if (filter->events[i] & KVM_PMU_MASKED_ENTRY_EXCLUDE) + break; + } + } + + filter->nr_includes = i; + filter->nr_excludes = filter->nevents - filter->nr_includes; + filter->includes = filter->events; + filter->excludes = filter->events + filter->nr_includes; + + return 0; +} + +int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp) +{ + struct kvm_pmu_event_filter __user *user_filter = argp; + struct kvm_x86_pmu_event_filter *filter; + struct kvm_pmu_event_filter tmp; + struct kvm_vcpu *vcpu; + unsigned long i; + size_t size; + int r; + + if (copy_from_user(&tmp, user_filter, sizeof(tmp))) + return -EFAULT; + + if (tmp.action != KVM_PMU_EVENT_ALLOW && + tmp.action != KVM_PMU_EVENT_DENY) + return -EINVAL; + + if (tmp.flags & ~KVM_PMU_EVENT_FLAGS_VALID_MASK) + return -EINVAL; + + if (tmp.nevents > KVM_PMU_EVENT_FILTER_MAX_EVENTS) + return -E2BIG; + + size = struct_size(filter, events, tmp.nevents); + filter = kzalloc(size, GFP_KERNEL_ACCOUNT); + if (!filter) + return -ENOMEM; + + filter->action = tmp.action; + filter->nevents = tmp.nevents; + filter->fixed_counter_bitmap = tmp.fixed_counter_bitmap; + filter->flags = tmp.flags; + + r = -EFAULT; + if (copy_from_user(filter->events, user_filter->events, + flex_array_size(filter, events, filter->nevents))) + goto cleanup; + + r = prepare_filter_lists(filter); + if (r) + goto cleanup; + + mutex_lock(&kvm->lock); + filter = rcu_replace_pointer(kvm->arch.pmu_event_filter, filter, + mutex_is_locked(&kvm->lock)); + mutex_unlock(&kvm->lock); + synchronize_srcu_expedited(&kvm->srcu); + + BUILD_BUG_ON(sizeof(((struct kvm_pmu *)0)->reprogram_pmi) > + sizeof(((struct kvm_pmu *)0)->__reprogram_pmi)); + + kvm_for_each_vcpu(i, vcpu, kvm) + atomic64_set(&vcpu_to_pmu(vcpu)->__reprogram_pmi, -1ull); + + kvm_make_all_cpus_request(kvm, KVM_REQ_PMU); + + r = 0; +cleanup: + kfree(filter); + return r; +} + +static __always_inline u32 fixed_counter_msr(u32 idx) +{ + return kvm_pmu_ops.FIXED_COUNTER_BASE + idx * kvm_pmu_ops.MSR_STRIDE; +} + +static __always_inline u32 gp_counter_msr(u32 idx) +{ + return kvm_pmu_ops.GP_COUNTER_BASE + idx * kvm_pmu_ops.MSR_STRIDE; +} + +static __always_inline u32 gp_eventsel_msr(u32 idx) +{ + return kvm_pmu_ops.GP_EVENTSEL_BASE + idx * kvm_pmu_ops.MSR_STRIDE; +} + +static void kvm_pmu_load_guest_pmcs(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + u32 i; + + /* + * No need to zero out unexposed GP/fixed counters/selectors since RDPMC + * is intercepted if hardware has counters that aren't visible to the + * guest (KVM will inject #GP as appropriate). + */ + for (i = 0; i < pmu->nr_arch_gp_counters; i++) { + pmc = &pmu->gp_counters[i]; + + if (pmc->counter != rdpmc(i)) + wrmsrq(gp_counter_msr(i), pmc->counter); + wrmsrq(gp_eventsel_msr(i), pmc->eventsel_hw); + } + for (i = 0; i < pmu->nr_arch_fixed_counters; i++) { + pmc = &pmu->fixed_counters[i]; + + if (pmc->counter != rdpmc(INTEL_PMC_FIXED_RDPMC_BASE | i)) + wrmsrq(fixed_counter_msr(i), pmc->counter); + } +} + +void kvm_mediated_pmu_load(struct kvm_vcpu *vcpu) +{ + if (!kvm_vcpu_has_mediated_pmu(vcpu) || + KVM_BUG_ON(!lapic_in_kernel(vcpu), vcpu->kvm)) + return; + + lockdep_assert_irqs_disabled(); + + perf_load_guest_context(); + + /* + * Explicitly clear PERF_GLOBAL_CTRL, as "loading" the guest's context + * disables all individual counters (if any were enabled), but doesn't + * globally disable the entire PMU. Loading event selectors and PMCs + * with guest values while PERF_GLOBAL_CTRL is non-zero will generate + * unexpected events and PMIs. + * + * VMX will enable/disable counters at VM-Enter/VM-Exit by atomically + * loading PERF_GLOBAL_CONTROL. SVM effectively performs the switch by + * configuring all events to be GUEST_ONLY. Clear PERF_GLOBAL_CONTROL + * even for SVM to minimize the damage if a perf event is left enabled, + * and to ensure a consistent starting state. + */ + wrmsrq(kvm_pmu_ops.PERF_GLOBAL_CTRL, 0); + + perf_load_guest_lvtpc(kvm_lapic_get_reg(vcpu->arch.apic, APIC_LVTPC)); + + kvm_pmu_load_guest_pmcs(vcpu); + + kvm_pmu_call(mediated_load)(vcpu); +} + +static void kvm_pmu_put_guest_pmcs(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc; + u32 i; + + /* + * Clear selectors and counters to ensure hardware doesn't count using + * guest controls when the host (perf) restores its state. + */ + for (i = 0; i < pmu->nr_arch_gp_counters; i++) { + pmc = &pmu->gp_counters[i]; + + pmc->counter = rdpmc(i); + if (pmc->counter) + wrmsrq(gp_counter_msr(i), 0); + if (pmc->eventsel_hw) + wrmsrq(gp_eventsel_msr(i), 0); + } + + for (i = 0; i < pmu->nr_arch_fixed_counters; i++) { + pmc = &pmu->fixed_counters[i]; + + pmc->counter = rdpmc(INTEL_PMC_FIXED_RDPMC_BASE | i); + if (pmc->counter) + wrmsrq(fixed_counter_msr(i), 0); + } +} + +void kvm_mediated_pmu_put(struct kvm_vcpu *vcpu) +{ + if (!kvm_vcpu_has_mediated_pmu(vcpu) || + KVM_BUG_ON(!lapic_in_kernel(vcpu), vcpu->kvm)) + return; + + lockdep_assert_irqs_disabled(); + + /* + * Defer handling of PERF_GLOBAL_CTRL to vendor code. On Intel, it's + * atomically cleared on VM-Exit, i.e. doesn't need to be clear here. + */ + kvm_pmu_call(mediated_put)(vcpu); + + kvm_pmu_put_guest_pmcs(vcpu); + + perf_put_guest_lvtpc(); + + perf_put_guest_context(); +} |