xref: /linux/arch/x86/kvm/pmu.h (revision e7cd4b811c9e019f5acbce85699c622b30194c24)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __KVM_X86_PMU_H
3 #define __KVM_X86_PMU_H
4 
5 #include <linux/nospec.h>
6 
7 #include <asm/kvm_host.h>
8 
9 #define vcpu_to_pmu(vcpu) (&(vcpu)->arch.pmu)
10 #define pmu_to_vcpu(pmu)  (container_of((pmu), struct kvm_vcpu, arch.pmu))
11 #define pmc_to_pmu(pmc)   (&(pmc)->vcpu->arch.pmu)
12 
13 #define MSR_IA32_MISC_ENABLE_PMU_RO_MASK (MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL |	\
14 					  MSR_IA32_MISC_ENABLE_BTS_UNAVAIL)
15 
16 /* retrieve the 4 bits for EN and PMI out of IA32_FIXED_CTR_CTRL */
17 #define fixed_ctrl_field(ctrl_reg, idx) \
18 	(((ctrl_reg) >> ((idx) * INTEL_FIXED_BITS_STRIDE)) & INTEL_FIXED_BITS_MASK)
19 
20 #define VMWARE_BACKDOOR_PMC_HOST_TSC		0x10000
21 #define VMWARE_BACKDOOR_PMC_REAL_TIME		0x10001
22 #define VMWARE_BACKDOOR_PMC_APPARENT_TIME	0x10002
23 
24 #define KVM_FIXED_PMC_BASE_IDX INTEL_PMC_IDX_FIXED
25 
26 struct kvm_pmu_emulated_event_selectors {
27 	u64 INSTRUCTIONS_RETIRED;
28 	u64 BRANCH_INSTRUCTIONS_RETIRED;
29 };
30 
31 struct kvm_pmu_ops {
32 	struct kvm_pmc *(*rdpmc_ecx_to_pmc)(struct kvm_vcpu *vcpu,
33 		unsigned int idx, u64 *mask);
34 	struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, u32 msr);
35 	int (*check_rdpmc_early)(struct kvm_vcpu *vcpu, unsigned int idx);
36 	bool (*is_valid_msr)(struct kvm_vcpu *vcpu, u32 msr);
37 	int (*get_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
38 	int (*set_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
39 	void (*refresh)(struct kvm_vcpu *vcpu);
40 	void (*init)(struct kvm_vcpu *vcpu);
41 	void (*reset)(struct kvm_vcpu *vcpu);
42 	void (*deliver_pmi)(struct kvm_vcpu *vcpu);
43 	void (*cleanup)(struct kvm_vcpu *vcpu);
44 
45 	const u64 EVENTSEL_EVENT;
46 	const int MAX_NR_GP_COUNTERS;
47 	const int MIN_NR_GP_COUNTERS;
48 };
49 
50 void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops);
51 
52 static inline bool kvm_pmu_has_perf_global_ctrl(struct kvm_pmu *pmu)
53 {
54 	/*
55 	 * Architecturally, Intel's SDM states that IA32_PERF_GLOBAL_CTRL is
56 	 * supported if "CPUID.0AH: EAX[7:0] > 0", i.e. if the PMU version is
57 	 * greater than zero.  However, KVM only exposes and emulates the MSR
58 	 * to/for the guest if the guest PMU supports at least "Architectural
59 	 * Performance Monitoring Version 2".
60 	 *
61 	 * AMD's version of PERF_GLOBAL_CTRL conveniently shows up with v2.
62 	 */
63 	return pmu->version > 1;
64 }
65 
66 /*
67  * KVM tracks all counters in 64-bit bitmaps, with general purpose counters
68  * mapped to bits 31:0 and fixed counters mapped to 63:32, e.g. fixed counter 0
69  * is tracked internally via index 32.  On Intel, (AMD doesn't support fixed
70  * counters), this mirrors how fixed counters are mapped to PERF_GLOBAL_CTRL
71  * and similar MSRs, i.e. tracking fixed counters at base index 32 reduces the
72  * amounter of boilerplate needed to iterate over PMCs *and* simplifies common
73  * enabling/disable/reset operations.
74  *
75  * WARNING!  This helper is only for lookups that are initiated by KVM, it is
76  * NOT safe for guest lookups, e.g. will do the wrong thing if passed a raw
77  * ECX value from RDPMC (fixed counters are accessed by setting bit 30 in ECX
78  * for RDPMC, not by adding 32 to the fixed counter index).
79  */
80 static inline struct kvm_pmc *kvm_pmc_idx_to_pmc(struct kvm_pmu *pmu, int idx)
81 {
82 	if (idx < pmu->nr_arch_gp_counters)
83 		return &pmu->gp_counters[idx];
84 
85 	idx -= KVM_FIXED_PMC_BASE_IDX;
86 	if (idx >= 0 && idx < pmu->nr_arch_fixed_counters)
87 		return &pmu->fixed_counters[idx];
88 
89 	return NULL;
90 }
91 
92 #define kvm_for_each_pmc(pmu, pmc, i, bitmap)			\
93 	for_each_set_bit(i, bitmap, X86_PMC_IDX_MAX)		\
94 		if (!(pmc = kvm_pmc_idx_to_pmc(pmu, i)))	\
95 			continue;				\
96 		else						\
97 
98 static inline u64 pmc_bitmask(struct kvm_pmc *pmc)
99 {
100 	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
101 
102 	return pmu->counter_bitmask[pmc->type];
103 }
104 
105 static inline u64 pmc_read_counter(struct kvm_pmc *pmc)
106 {
107 	u64 counter, enabled, running;
108 
109 	counter = pmc->counter + pmc->emulated_counter;
110 
111 	if (pmc->perf_event && !pmc->is_paused)
112 		counter += perf_event_read_value(pmc->perf_event,
113 						 &enabled, &running);
114 	/* FIXME: Scaling needed? */
115 	return counter & pmc_bitmask(pmc);
116 }
117 
118 void pmc_write_counter(struct kvm_pmc *pmc, u64 val);
119 
120 static inline bool pmc_is_gp(struct kvm_pmc *pmc)
121 {
122 	return pmc->type == KVM_PMC_GP;
123 }
124 
125 static inline bool pmc_is_fixed(struct kvm_pmc *pmc)
126 {
127 	return pmc->type == KVM_PMC_FIXED;
128 }
129 
130 static inline bool kvm_valid_perf_global_ctrl(struct kvm_pmu *pmu,
131 						 u64 data)
132 {
133 	return !(pmu->global_ctrl_rsvd & data);
134 }
135 
136 /* returns general purpose PMC with the specified MSR. Note that it can be
137  * used for both PERFCTRn and EVNTSELn; that is why it accepts base as a
138  * parameter to tell them apart.
139  */
140 static inline struct kvm_pmc *get_gp_pmc(struct kvm_pmu *pmu, u32 msr,
141 					 u32 base)
142 {
143 	if (msr >= base && msr < base + pmu->nr_arch_gp_counters) {
144 		u32 index = array_index_nospec(msr - base,
145 					       pmu->nr_arch_gp_counters);
146 
147 		return &pmu->gp_counters[index];
148 	}
149 
150 	return NULL;
151 }
152 
153 /* returns fixed PMC with the specified MSR */
154 static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
155 {
156 	int base = MSR_CORE_PERF_FIXED_CTR0;
157 
158 	if (msr >= base && msr < base + pmu->nr_arch_fixed_counters) {
159 		u32 index = array_index_nospec(msr - base,
160 					       pmu->nr_arch_fixed_counters);
161 
162 		return &pmu->fixed_counters[index];
163 	}
164 
165 	return NULL;
166 }
167 
168 static inline bool pmc_speculative_in_use(struct kvm_pmc *pmc)
169 {
170 	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
171 
172 	if (pmc_is_fixed(pmc))
173 		return fixed_ctrl_field(pmu->fixed_ctr_ctrl,
174 					pmc->idx - KVM_FIXED_PMC_BASE_IDX) &
175 					(INTEL_FIXED_0_KERNEL | INTEL_FIXED_0_USER);
176 
177 	return pmc->eventsel & ARCH_PERFMON_EVENTSEL_ENABLE;
178 }
179 
180 extern struct x86_pmu_capability kvm_pmu_cap;
181 extern struct kvm_pmu_emulated_event_selectors kvm_pmu_eventsel;
182 
183 static inline void kvm_init_pmu_capability(const struct kvm_pmu_ops *pmu_ops)
184 {
185 	bool is_intel = boot_cpu_data.x86_vendor == X86_VENDOR_INTEL;
186 	int min_nr_gp_ctrs = pmu_ops->MIN_NR_GP_COUNTERS;
187 
188 	/*
189 	 * Hybrid PMUs don't play nice with virtualization without careful
190 	 * configuration by userspace, and KVM's APIs for reporting supported
191 	 * vPMU features do not account for hybrid PMUs.  Disable vPMU support
192 	 * for hybrid PMUs until KVM gains a way to let userspace opt-in.
193 	 */
194 	if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
195 		enable_pmu = false;
196 
197 	if (enable_pmu) {
198 		perf_get_x86_pmu_capability(&kvm_pmu_cap);
199 
200 		/*
201 		 * WARN if perf did NOT disable hardware PMU if the number of
202 		 * architecturally required GP counters aren't present, i.e. if
203 		 * there are a non-zero number of counters, but fewer than what
204 		 * is architecturally required.
205 		 */
206 		if (!kvm_pmu_cap.num_counters_gp ||
207 		    WARN_ON_ONCE(kvm_pmu_cap.num_counters_gp < min_nr_gp_ctrs))
208 			enable_pmu = false;
209 		else if (is_intel && !kvm_pmu_cap.version)
210 			enable_pmu = false;
211 	}
212 
213 	if (!enable_pmu) {
214 		memset(&kvm_pmu_cap, 0, sizeof(kvm_pmu_cap));
215 		return;
216 	}
217 
218 	kvm_pmu_cap.version = min(kvm_pmu_cap.version, 2);
219 	kvm_pmu_cap.num_counters_gp = min(kvm_pmu_cap.num_counters_gp,
220 					  pmu_ops->MAX_NR_GP_COUNTERS);
221 	kvm_pmu_cap.num_counters_fixed = min(kvm_pmu_cap.num_counters_fixed,
222 					     KVM_MAX_NR_FIXED_COUNTERS);
223 
224 	kvm_pmu_eventsel.INSTRUCTIONS_RETIRED =
225 		perf_get_hw_event_config(PERF_COUNT_HW_INSTRUCTIONS);
226 	kvm_pmu_eventsel.BRANCH_INSTRUCTIONS_RETIRED =
227 		perf_get_hw_event_config(PERF_COUNT_HW_BRANCH_INSTRUCTIONS);
228 }
229 
230 static inline void kvm_pmu_request_counter_reprogram(struct kvm_pmc *pmc)
231 {
232 	set_bit(pmc->idx, pmc_to_pmu(pmc)->reprogram_pmi);
233 	kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
234 }
235 
236 static inline void reprogram_counters(struct kvm_pmu *pmu, u64 diff)
237 {
238 	int bit;
239 
240 	if (!diff)
241 		return;
242 
243 	for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX)
244 		set_bit(bit, pmu->reprogram_pmi);
245 	kvm_make_request(KVM_REQ_PMU, pmu_to_vcpu(pmu));
246 }
247 
248 /*
249  * Check if a PMC is enabled by comparing it against global_ctrl bits.
250  *
251  * If the vPMU doesn't have global_ctrl MSR, all vPMCs are enabled.
252  */
253 static inline bool pmc_is_globally_enabled(struct kvm_pmc *pmc)
254 {
255 	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
256 
257 	if (!kvm_pmu_has_perf_global_ctrl(pmu))
258 		return true;
259 
260 	return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
261 }
262 
263 void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu);
264 void kvm_pmu_handle_event(struct kvm_vcpu *vcpu);
265 int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data);
266 int kvm_pmu_check_rdpmc_early(struct kvm_vcpu *vcpu, unsigned int idx);
267 bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr);
268 int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
269 int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
270 void kvm_pmu_refresh(struct kvm_vcpu *vcpu);
271 void kvm_pmu_init(struct kvm_vcpu *vcpu);
272 void kvm_pmu_cleanup(struct kvm_vcpu *vcpu);
273 void kvm_pmu_destroy(struct kvm_vcpu *vcpu);
274 int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp);
275 void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, u64 eventsel);
276 
277 bool is_vmware_backdoor_pmc(u32 pmc_idx);
278 
279 extern struct kvm_pmu_ops intel_pmu_ops;
280 extern struct kvm_pmu_ops amd_pmu_ops;
281 #endif /* __KVM_X86_PMU_H */
282