https://github.com/torvalds/linux
Tip revision: fec50db7033ea478773b159e0e2efb135270e3b7 authored by Linus Torvalds on 07 April 2024, 20:22:46 UTC
Linux 6.9-rc3
Linux 6.9-rc3
Tip revision: fec50db
pmu.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __KVM_X86_PMU_H
#define __KVM_X86_PMU_H
#include <linux/nospec.h>
#include <asm/kvm_host.h>
#define vcpu_to_pmu(vcpu) (&(vcpu)->arch.pmu)
#define pmu_to_vcpu(pmu) (container_of((pmu), struct kvm_vcpu, arch.pmu))
#define pmc_to_pmu(pmc) (&(pmc)->vcpu->arch.pmu)
#define MSR_IA32_MISC_ENABLE_PMU_RO_MASK (MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL | \
MSR_IA32_MISC_ENABLE_BTS_UNAVAIL)
/* retrieve the 4 bits for EN and PMI out of IA32_FIXED_CTR_CTRL */
#define fixed_ctrl_field(ctrl_reg, idx) (((ctrl_reg) >> ((idx)*4)) & 0xf)
#define VMWARE_BACKDOOR_PMC_HOST_TSC 0x10000
#define VMWARE_BACKDOOR_PMC_REAL_TIME 0x10001
#define VMWARE_BACKDOOR_PMC_APPARENT_TIME 0x10002
#define KVM_FIXED_PMC_BASE_IDX INTEL_PMC_IDX_FIXED
struct kvm_pmu_emulated_event_selectors {
u64 INSTRUCTIONS_RETIRED;
u64 BRANCH_INSTRUCTIONS_RETIRED;
};
struct kvm_pmu_ops {
struct kvm_pmc *(*rdpmc_ecx_to_pmc)(struct kvm_vcpu *vcpu,
unsigned int idx, u64 *mask);
struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, u32 msr);
int (*check_rdpmc_early)(struct kvm_vcpu *vcpu, unsigned int idx);
bool (*is_valid_msr)(struct kvm_vcpu *vcpu, u32 msr);
int (*get_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
int (*set_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
void (*refresh)(struct kvm_vcpu *vcpu);
void (*init)(struct kvm_vcpu *vcpu);
void (*reset)(struct kvm_vcpu *vcpu);
void (*deliver_pmi)(struct kvm_vcpu *vcpu);
void (*cleanup)(struct kvm_vcpu *vcpu);
const u64 EVENTSEL_EVENT;
const int MAX_NR_GP_COUNTERS;
const int MIN_NR_GP_COUNTERS;
};
void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops);
static inline bool kvm_pmu_has_perf_global_ctrl(struct kvm_pmu *pmu)
{
/*
* Architecturally, Intel's SDM states that IA32_PERF_GLOBAL_CTRL is
* supported if "CPUID.0AH: EAX[7:0] > 0", i.e. if the PMU version is
* greater than zero. However, KVM only exposes and emulates the MSR
* to/for the guest if the guest PMU supports at least "Architectural
* Performance Monitoring Version 2".
*
* AMD's version of PERF_GLOBAL_CTRL conveniently shows up with v2.
*/
return pmu->version > 1;
}
/*
* KVM tracks all counters in 64-bit bitmaps, with general purpose counters
* mapped to bits 31:0 and fixed counters mapped to 63:32, e.g. fixed counter 0
* is tracked internally via index 32. On Intel, (AMD doesn't support fixed
* counters), this mirrors how fixed counters are mapped to PERF_GLOBAL_CTRL
* and similar MSRs, i.e. tracking fixed counters at base index 32 reduces the
* amounter of boilerplate needed to iterate over PMCs *and* simplifies common
* enabling/disable/reset operations.
*
* WARNING! This helper is only for lookups that are initiated by KVM, it is
* NOT safe for guest lookups, e.g. will do the wrong thing if passed a raw
* ECX value from RDPMC (fixed counters are accessed by setting bit 30 in ECX
* for RDPMC, not by adding 32 to the fixed counter index).
*/
static inline struct kvm_pmc *kvm_pmc_idx_to_pmc(struct kvm_pmu *pmu, int idx)
{
if (idx < pmu->nr_arch_gp_counters)
return &pmu->gp_counters[idx];
idx -= KVM_FIXED_PMC_BASE_IDX;
if (idx >= 0 && idx < pmu->nr_arch_fixed_counters)
return &pmu->fixed_counters[idx];
return NULL;
}
#define kvm_for_each_pmc(pmu, pmc, i, bitmap) \
for_each_set_bit(i, bitmap, X86_PMC_IDX_MAX) \
if (!(pmc = kvm_pmc_idx_to_pmc(pmu, i))) \
continue; \
else \
static inline u64 pmc_bitmask(struct kvm_pmc *pmc)
{
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
return pmu->counter_bitmask[pmc->type];
}
static inline u64 pmc_read_counter(struct kvm_pmc *pmc)
{
u64 counter, enabled, running;
counter = pmc->counter + pmc->emulated_counter;
if (pmc->perf_event && !pmc->is_paused)
counter += perf_event_read_value(pmc->perf_event,
&enabled, &running);
/* FIXME: Scaling needed? */
return counter & pmc_bitmask(pmc);
}
void pmc_write_counter(struct kvm_pmc *pmc, u64 val);
static inline bool pmc_is_gp(struct kvm_pmc *pmc)
{
return pmc->type == KVM_PMC_GP;
}
static inline bool pmc_is_fixed(struct kvm_pmc *pmc)
{
return pmc->type == KVM_PMC_FIXED;
}
static inline bool kvm_valid_perf_global_ctrl(struct kvm_pmu *pmu,
u64 data)
{
return !(pmu->global_ctrl_mask & data);
}
/* returns general purpose PMC with the specified MSR. Note that it can be
* used for both PERFCTRn and EVNTSELn; that is why it accepts base as a
* parameter to tell them apart.
*/
static inline struct kvm_pmc *get_gp_pmc(struct kvm_pmu *pmu, u32 msr,
u32 base)
{
if (msr >= base && msr < base + pmu->nr_arch_gp_counters) {
u32 index = array_index_nospec(msr - base,
pmu->nr_arch_gp_counters);
return &pmu->gp_counters[index];
}
return NULL;
}
/* returns fixed PMC with the specified MSR */
static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
{
int base = MSR_CORE_PERF_FIXED_CTR0;
if (msr >= base && msr < base + pmu->nr_arch_fixed_counters) {
u32 index = array_index_nospec(msr - base,
pmu->nr_arch_fixed_counters);
return &pmu->fixed_counters[index];
}
return NULL;
}
static inline bool pmc_speculative_in_use(struct kvm_pmc *pmc)
{
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
if (pmc_is_fixed(pmc))
return fixed_ctrl_field(pmu->fixed_ctr_ctrl,
pmc->idx - KVM_FIXED_PMC_BASE_IDX) & 0x3;
return pmc->eventsel & ARCH_PERFMON_EVENTSEL_ENABLE;
}
extern struct x86_pmu_capability kvm_pmu_cap;
extern struct kvm_pmu_emulated_event_selectors kvm_pmu_eventsel;
static inline void kvm_init_pmu_capability(const 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;
if (enable_pmu) {
perf_get_x86_pmu_capability(&kvm_pmu_cap);
/*
* 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_pmu_cap.num_counters_gp ||
WARN_ON_ONCE(kvm_pmu_cap.num_counters_gp < min_nr_gp_ctrs))
enable_pmu = false;
else if (is_intel && !kvm_pmu_cap.version)
enable_pmu = false;
}
if (!enable_pmu) {
memset(&kvm_pmu_cap, 0, sizeof(kvm_pmu_cap));
return;
}
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_PMC_MAX_FIXED);
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);
}
static inline void kvm_pmu_request_counter_reprogram(struct kvm_pmc *pmc)
{
set_bit(pmc->idx, pmc_to_pmu(pmc)->reprogram_pmi);
kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
}
static inline void reprogram_counters(struct kvm_pmu *pmu, u64 diff)
{
int bit;
if (!diff)
return;
for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX)
set_bit(bit, pmu->reprogram_pmi);
kvm_make_request(KVM_REQ_PMU, pmu_to_vcpu(pmu));
}
/*
* Check if a PMC is enabled by comparing it against global_ctrl bits.
*
* If the vPMU doesn't have global_ctrl MSR, all vPMCs are enabled.
*/
static inline bool pmc_is_globally_enabled(struct kvm_pmc *pmc)
{
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
if (!kvm_pmu_has_perf_global_ctrl(pmu))
return true;
return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
}
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);
int kvm_pmu_check_rdpmc_early(struct kvm_vcpu *vcpu, unsigned int idx);
bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr);
int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
void kvm_pmu_refresh(struct kvm_vcpu *vcpu);
void kvm_pmu_init(struct kvm_vcpu *vcpu);
void kvm_pmu_cleanup(struct kvm_vcpu *vcpu);
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 is_vmware_backdoor_pmc(u32 pmc_idx);
extern struct kvm_pmu_ops intel_pmu_ops;
extern struct kvm_pmu_ops amd_pmu_ops;
#endif /* __KVM_X86_PMU_H */