xref: /openbmc/linux/arch/x86/kvm/pmu.h (revision 3ddc8b84)
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 #define vcpu_to_pmu(vcpu) (&(vcpu)->arch.pmu)
8 #define pmu_to_vcpu(pmu)  (container_of((pmu), struct kvm_vcpu, arch.pmu))
9 #define pmc_to_pmu(pmc)   (&(pmc)->vcpu->arch.pmu)
10 
11 #define MSR_IA32_MISC_ENABLE_PMU_RO_MASK (MSR_IA32_MISC_ENABLE_PEBS_UNAVAIL |	\
12 					  MSR_IA32_MISC_ENABLE_BTS_UNAVAIL)
13 
14 /* retrieve the 4 bits for EN and PMI out of IA32_FIXED_CTR_CTRL */
15 #define fixed_ctrl_field(ctrl_reg, idx) (((ctrl_reg) >> ((idx)*4)) & 0xf)
16 
17 #define VMWARE_BACKDOOR_PMC_HOST_TSC		0x10000
18 #define VMWARE_BACKDOOR_PMC_REAL_TIME		0x10001
19 #define VMWARE_BACKDOOR_PMC_APPARENT_TIME	0x10002
20 
21 struct kvm_pmu_ops {
22 	bool (*hw_event_available)(struct kvm_pmc *pmc);
23 	struct kvm_pmc *(*pmc_idx_to_pmc)(struct kvm_pmu *pmu, int pmc_idx);
24 	struct kvm_pmc *(*rdpmc_ecx_to_pmc)(struct kvm_vcpu *vcpu,
25 		unsigned int idx, u64 *mask);
26 	struct kvm_pmc *(*msr_idx_to_pmc)(struct kvm_vcpu *vcpu, u32 msr);
27 	bool (*is_valid_rdpmc_ecx)(struct kvm_vcpu *vcpu, unsigned int idx);
28 	bool (*is_valid_msr)(struct kvm_vcpu *vcpu, u32 msr);
29 	int (*get_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
30 	int (*set_msr)(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
31 	void (*refresh)(struct kvm_vcpu *vcpu);
32 	void (*init)(struct kvm_vcpu *vcpu);
33 	void (*reset)(struct kvm_vcpu *vcpu);
34 	void (*deliver_pmi)(struct kvm_vcpu *vcpu);
35 	void (*cleanup)(struct kvm_vcpu *vcpu);
36 
37 	const u64 EVENTSEL_EVENT;
38 	const int MAX_NR_GP_COUNTERS;
39 	const int MIN_NR_GP_COUNTERS;
40 };
41 
42 void kvm_pmu_ops_update(const struct kvm_pmu_ops *pmu_ops);
43 
44 static inline bool kvm_pmu_has_perf_global_ctrl(struct kvm_pmu *pmu)
45 {
46 	/*
47 	 * Architecturally, Intel's SDM states that IA32_PERF_GLOBAL_CTRL is
48 	 * supported if "CPUID.0AH: EAX[7:0] > 0", i.e. if the PMU version is
49 	 * greater than zero.  However, KVM only exposes and emulates the MSR
50 	 * to/for the guest if the guest PMU supports at least "Architectural
51 	 * Performance Monitoring Version 2".
52 	 *
53 	 * AMD's version of PERF_GLOBAL_CTRL conveniently shows up with v2.
54 	 */
55 	return pmu->version > 1;
56 }
57 
58 static inline u64 pmc_bitmask(struct kvm_pmc *pmc)
59 {
60 	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
61 
62 	return pmu->counter_bitmask[pmc->type];
63 }
64 
65 static inline u64 pmc_read_counter(struct kvm_pmc *pmc)
66 {
67 	u64 counter, enabled, running;
68 
69 	counter = pmc->counter;
70 	if (pmc->perf_event && !pmc->is_paused)
71 		counter += perf_event_read_value(pmc->perf_event,
72 						 &enabled, &running);
73 	/* FIXME: Scaling needed? */
74 	return counter & pmc_bitmask(pmc);
75 }
76 
77 static inline void pmc_write_counter(struct kvm_pmc *pmc, u64 val)
78 {
79 	pmc->counter += val - pmc_read_counter(pmc);
80 	pmc->counter &= pmc_bitmask(pmc);
81 }
82 
83 static inline void pmc_release_perf_event(struct kvm_pmc *pmc)
84 {
85 	if (pmc->perf_event) {
86 		perf_event_release_kernel(pmc->perf_event);
87 		pmc->perf_event = NULL;
88 		pmc->current_config = 0;
89 		pmc_to_pmu(pmc)->event_count--;
90 	}
91 }
92 
93 static inline void pmc_stop_counter(struct kvm_pmc *pmc)
94 {
95 	if (pmc->perf_event) {
96 		pmc->counter = pmc_read_counter(pmc);
97 		pmc_release_perf_event(pmc);
98 	}
99 }
100 
101 static inline bool pmc_is_gp(struct kvm_pmc *pmc)
102 {
103 	return pmc->type == KVM_PMC_GP;
104 }
105 
106 static inline bool pmc_is_fixed(struct kvm_pmc *pmc)
107 {
108 	return pmc->type == KVM_PMC_FIXED;
109 }
110 
111 static inline bool kvm_valid_perf_global_ctrl(struct kvm_pmu *pmu,
112 						 u64 data)
113 {
114 	return !(pmu->global_ctrl_mask & data);
115 }
116 
117 /* returns general purpose PMC with the specified MSR. Note that it can be
118  * used for both PERFCTRn and EVNTSELn; that is why it accepts base as a
119  * parameter to tell them apart.
120  */
121 static inline struct kvm_pmc *get_gp_pmc(struct kvm_pmu *pmu, u32 msr,
122 					 u32 base)
123 {
124 	if (msr >= base && msr < base + pmu->nr_arch_gp_counters) {
125 		u32 index = array_index_nospec(msr - base,
126 					       pmu->nr_arch_gp_counters);
127 
128 		return &pmu->gp_counters[index];
129 	}
130 
131 	return NULL;
132 }
133 
134 /* returns fixed PMC with the specified MSR */
135 static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr)
136 {
137 	int base = MSR_CORE_PERF_FIXED_CTR0;
138 
139 	if (msr >= base && msr < base + pmu->nr_arch_fixed_counters) {
140 		u32 index = array_index_nospec(msr - base,
141 					       pmu->nr_arch_fixed_counters);
142 
143 		return &pmu->fixed_counters[index];
144 	}
145 
146 	return NULL;
147 }
148 
149 static inline u64 get_sample_period(struct kvm_pmc *pmc, u64 counter_value)
150 {
151 	u64 sample_period = (-counter_value) & pmc_bitmask(pmc);
152 
153 	if (!sample_period)
154 		sample_period = pmc_bitmask(pmc) + 1;
155 	return sample_period;
156 }
157 
158 static inline void pmc_update_sample_period(struct kvm_pmc *pmc)
159 {
160 	if (!pmc->perf_event || pmc->is_paused ||
161 	    !is_sampling_event(pmc->perf_event))
162 		return;
163 
164 	perf_event_period(pmc->perf_event,
165 			  get_sample_period(pmc, pmc->counter));
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 - INTEL_PMC_IDX_FIXED) & 0x3;
175 
176 	return pmc->eventsel & ARCH_PERFMON_EVENTSEL_ENABLE;
177 }
178 
179 extern struct x86_pmu_capability kvm_pmu_cap;
180 
181 static inline void kvm_init_pmu_capability(const struct kvm_pmu_ops *pmu_ops)
182 {
183 	bool is_intel = boot_cpu_data.x86_vendor == X86_VENDOR_INTEL;
184 	int min_nr_gp_ctrs = pmu_ops->MIN_NR_GP_COUNTERS;
185 
186 	/*
187 	 * Hybrid PMUs don't play nice with virtualization without careful
188 	 * configuration by userspace, and KVM's APIs for reporting supported
189 	 * vPMU features do not account for hybrid PMUs.  Disable vPMU support
190 	 * for hybrid PMUs until KVM gains a way to let userspace opt-in.
191 	 */
192 	if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
193 		enable_pmu = false;
194 
195 	if (enable_pmu) {
196 		perf_get_x86_pmu_capability(&kvm_pmu_cap);
197 
198 		/*
199 		 * WARN if perf did NOT disable hardware PMU if the number of
200 		 * architecturally required GP counters aren't present, i.e. if
201 		 * there are a non-zero number of counters, but fewer than what
202 		 * is architecturally required.
203 		 */
204 		if (!kvm_pmu_cap.num_counters_gp ||
205 		    WARN_ON_ONCE(kvm_pmu_cap.num_counters_gp < min_nr_gp_ctrs))
206 			enable_pmu = false;
207 		else if (is_intel && !kvm_pmu_cap.version)
208 			enable_pmu = false;
209 	}
210 
211 	if (!enable_pmu) {
212 		memset(&kvm_pmu_cap, 0, sizeof(kvm_pmu_cap));
213 		return;
214 	}
215 
216 	kvm_pmu_cap.version = min(kvm_pmu_cap.version, 2);
217 	kvm_pmu_cap.num_counters_gp = min(kvm_pmu_cap.num_counters_gp,
218 					  pmu_ops->MAX_NR_GP_COUNTERS);
219 	kvm_pmu_cap.num_counters_fixed = min(kvm_pmu_cap.num_counters_fixed,
220 					     KVM_PMC_MAX_FIXED);
221 }
222 
223 static inline void kvm_pmu_request_counter_reprogram(struct kvm_pmc *pmc)
224 {
225 	set_bit(pmc->idx, pmc_to_pmu(pmc)->reprogram_pmi);
226 	kvm_make_request(KVM_REQ_PMU, pmc->vcpu);
227 }
228 
229 static inline void reprogram_counters(struct kvm_pmu *pmu, u64 diff)
230 {
231 	int bit;
232 
233 	if (!diff)
234 		return;
235 
236 	for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX)
237 		set_bit(bit, pmu->reprogram_pmi);
238 	kvm_make_request(KVM_REQ_PMU, pmu_to_vcpu(pmu));
239 }
240 
241 /*
242  * Check if a PMC is enabled by comparing it against global_ctrl bits.
243  *
244  * If the vPMU doesn't have global_ctrl MSR, all vPMCs are enabled.
245  */
246 static inline bool pmc_is_globally_enabled(struct kvm_pmc *pmc)
247 {
248 	struct kvm_pmu *pmu = pmc_to_pmu(pmc);
249 
250 	if (!kvm_pmu_has_perf_global_ctrl(pmu))
251 		return true;
252 
253 	return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
254 }
255 
256 void kvm_pmu_deliver_pmi(struct kvm_vcpu *vcpu);
257 void kvm_pmu_handle_event(struct kvm_vcpu *vcpu);
258 int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data);
259 bool kvm_pmu_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx);
260 bool kvm_pmu_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr);
261 int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
262 int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info);
263 void kvm_pmu_refresh(struct kvm_vcpu *vcpu);
264 void kvm_pmu_reset(struct kvm_vcpu *vcpu);
265 void kvm_pmu_init(struct kvm_vcpu *vcpu);
266 void kvm_pmu_cleanup(struct kvm_vcpu *vcpu);
267 void kvm_pmu_destroy(struct kvm_vcpu *vcpu);
268 int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp);
269 void kvm_pmu_trigger_event(struct kvm_vcpu *vcpu, u64 perf_hw_id);
270 
271 bool is_vmware_backdoor_pmc(u32 pmc_idx);
272 
273 extern struct kvm_pmu_ops intel_pmu_ops;
274 extern struct kvm_pmu_ops amd_pmu_ops;
275 #endif /* __KVM_X86_PMU_H */
276