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  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * KVM PMU support for AMD
  4 *
  5 * Copyright 2015, Red Hat, Inc. and/or its affiliates.
  6 *
  7 * Author:
  8 *   Wei Huang <wei@redhat.com>
  9 *
 10 * Implementation is based on pmu_intel.c file
 11 */
 12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 13
 14#include <linux/types.h>
 15#include <linux/kvm_host.h>
 16#include <linux/perf_event.h>
 17#include "x86.h"
 18#include "cpuid.h"
 19#include "lapic.h"
 20#include "pmu.h"
 21#include "svm.h"
 22
 23enum pmu_type {
 24	PMU_TYPE_COUNTER = 0,
 25	PMU_TYPE_EVNTSEL,
 26};
 27
 28static struct kvm_pmc *amd_pmu_get_pmc(struct kvm_pmu *pmu, int pmc_idx)
 29{
 30	unsigned int num_counters = pmu->nr_arch_gp_counters;
 31
 32	if (pmc_idx >= num_counters)
 33		return NULL;
 34
 35	return &pmu->gp_counters[array_index_nospec(pmc_idx, num_counters)];
 36}
 37
 38static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr,
 39					     enum pmu_type type)
 40{
 41	struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu);
 42	unsigned int idx;
 43
 44	if (!vcpu->kvm->arch.enable_pmu)
 45		return NULL;
 46
 47	switch (msr) {
 48	case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5:
 49		if (!guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE))
 50			return NULL;
 51		/*
 52		 * Each PMU counter has a pair of CTL and CTR MSRs. CTLn
 53		 * MSRs (accessed via EVNTSEL) are even, CTRn MSRs are odd.
 54		 */
 55		idx = (unsigned int)((msr - MSR_F15H_PERF_CTL0) / 2);
 56		if (!(msr & 0x1) != (type == PMU_TYPE_EVNTSEL))
 57			return NULL;
 58		break;
 59	case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
 60		if (type != PMU_TYPE_EVNTSEL)
 61			return NULL;
 62		idx = msr - MSR_K7_EVNTSEL0;
 63		break;
 64	case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
 65		if (type != PMU_TYPE_COUNTER)
 66			return NULL;
 67		idx = msr - MSR_K7_PERFCTR0;
 68		break;
 69	default:
 70		return NULL;
 71	}
 72
 73	return amd_pmu_get_pmc(pmu, idx);
 74}
 75
 76static int amd_check_rdpmc_early(struct kvm_vcpu *vcpu, unsigned int idx)
 77{
 78	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 79
 80	if (idx >= pmu->nr_arch_gp_counters)
 81		return -EINVAL;
 82
 83	return 0;
 84}
 85
 86/* idx is the ECX register of RDPMC instruction */
 87static struct kvm_pmc *amd_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu,
 88	unsigned int idx, u64 *mask)
 89{
 90	return amd_pmu_get_pmc(vcpu_to_pmu(vcpu), idx);
 91}
 92
 93static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, u32 msr)
 94{
 95	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 96	struct kvm_pmc *pmc;
 97
 98	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
 99	pmc = pmc ? pmc : get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
100
101	return pmc;
102}
103
104static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
105{
106	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
107
108	switch (msr) {
109	case MSR_K7_EVNTSEL0 ... MSR_K7_PERFCTR3:
110		return pmu->version > 0;
111	case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5:
112		return guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE);
113	case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS:
114	case MSR_AMD64_PERF_CNTR_GLOBAL_CTL:
115	case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR:
116		return pmu->version > 1;
117	default:
118		if (msr > MSR_F15H_PERF_CTR5 &&
119		    msr < MSR_F15H_PERF_CTL0 + 2 * pmu->nr_arch_gp_counters)
120			return pmu->version > 1;
121		break;
122	}
123
124	return amd_msr_idx_to_pmc(vcpu, msr);
125}
126
127static int amd_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
128{
129	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
130	struct kvm_pmc *pmc;
131	u32 msr = msr_info->index;
132
133	/* MSR_PERFCTRn */
134	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
135	if (pmc) {
136		msr_info->data = pmc_read_counter(pmc);
137		return 0;
138	}
139	/* MSR_EVNTSELn */
140	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
141	if (pmc) {
142		msr_info->data = pmc->eventsel;
143		return 0;
144	}
145
146	return 1;
147}
148
149static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
150{
151	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
152	struct kvm_pmc *pmc;
153	u32 msr = msr_info->index;
154	u64 data = msr_info->data;
155
156	/* MSR_PERFCTRn */
157	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
158	if (pmc) {
159		pmc_write_counter(pmc, data);
160		return 0;
161	}
162	/* MSR_EVNTSELn */
163	pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
164	if (pmc) {
165		data &= ~pmu->reserved_bits;
166		if (data != pmc->eventsel) {
167			pmc->eventsel = data;
168			kvm_pmu_request_counter_reprogram(pmc);
169		}
170		return 0;
171	}
172
173	return 1;
174}
175
176static void amd_pmu_refresh(struct kvm_vcpu *vcpu)
177{
178	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
179	union cpuid_0x80000022_ebx ebx;
180
181	pmu->version = 1;
182	if (guest_cpuid_has(vcpu, X86_FEATURE_PERFMON_V2)) {
183		pmu->version = 2;
184		/*
185		 * Note, PERFMON_V2 is also in 0x80000022.0x0, i.e. the guest
186		 * CPUID entry is guaranteed to be non-NULL.
187		 */
188		BUILD_BUG_ON(x86_feature_cpuid(X86_FEATURE_PERFMON_V2).function != 0x80000022 ||
189			     x86_feature_cpuid(X86_FEATURE_PERFMON_V2).index);
190		ebx.full = kvm_find_cpuid_entry_index(vcpu, 0x80000022, 0)->ebx;
191		pmu->nr_arch_gp_counters = ebx.split.num_core_pmc;
192	} else if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) {
193		pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS_CORE;
194	} else {
195		pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS;
196	}
197
198	pmu->nr_arch_gp_counters = min_t(unsigned int, pmu->nr_arch_gp_counters,
199					 kvm_pmu_cap.num_counters_gp);
200
201	if (pmu->version > 1) {
202		pmu->global_ctrl_rsvd = ~((1ull << pmu->nr_arch_gp_counters) - 1);
203		pmu->global_status_rsvd = pmu->global_ctrl_rsvd;
204	}
205
206	pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << 48) - 1;
207	pmu->reserved_bits = 0xfffffff000280000ull;
208	pmu->raw_event_mask = AMD64_RAW_EVENT_MASK;
209	/* not applicable to AMD; but clean them to prevent any fall out */
210	pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
211	pmu->nr_arch_fixed_counters = 0;
212	bitmap_set(pmu->all_valid_pmc_idx, 0, pmu->nr_arch_gp_counters);
213}
214
215static void amd_pmu_init(struct kvm_vcpu *vcpu)
216{
217	struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
218	int i;
219
220	BUILD_BUG_ON(KVM_MAX_NR_AMD_GP_COUNTERS > AMD64_NUM_COUNTERS_CORE);
221
222	for (i = 0; i < KVM_MAX_NR_AMD_GP_COUNTERS; i++) {
223		pmu->gp_counters[i].type = KVM_PMC_GP;
224		pmu->gp_counters[i].vcpu = vcpu;
225		pmu->gp_counters[i].idx = i;
226		pmu->gp_counters[i].current_config = 0;
227	}
228}
229
230struct kvm_pmu_ops amd_pmu_ops __initdata = {
231	.rdpmc_ecx_to_pmc = amd_rdpmc_ecx_to_pmc,
232	.msr_idx_to_pmc = amd_msr_idx_to_pmc,
233	.check_rdpmc_early = amd_check_rdpmc_early,
234	.is_valid_msr = amd_is_valid_msr,
235	.get_msr = amd_pmu_get_msr,
236	.set_msr = amd_pmu_set_msr,
237	.refresh = amd_pmu_refresh,
238	.init = amd_pmu_init,
239	.EVENTSEL_EVENT = AMD64_EVENTSEL_EVENT,
240	.MAX_NR_GP_COUNTERS = KVM_MAX_NR_AMD_GP_COUNTERS,
241	.MIN_NR_GP_COUNTERS = AMD64_NUM_COUNTERS,
242};