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1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef ARCH_X86_KVM_CPUID_H
3 #define ARCH_X86_KVM_CPUID_H
4 
5 #include "x86.h"
6 #include <asm/cpu.h>
7 #include <asm/processor.h>
8 #include <uapi/asm/kvm_para.h>
9 
10 extern u32 kvm_cpu_caps[NCAPINTS] __read_mostly;
11 void kvm_set_cpu_caps(void);
12 
13 void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu);
14 void kvm_update_pv_runtime(struct kvm_vcpu *vcpu);
15 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
16 					      u32 function, u32 index);
17 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
18 			    struct kvm_cpuid_entry2 __user *entries,
19 			    unsigned int type);
20 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
21 			     struct kvm_cpuid *cpuid,
22 			     struct kvm_cpuid_entry __user *entries);
23 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
24 			      struct kvm_cpuid2 *cpuid,
25 			      struct kvm_cpuid_entry2 __user *entries);
26 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
27 			      struct kvm_cpuid2 *cpuid,
28 			      struct kvm_cpuid_entry2 __user *entries);
29 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
30 	       u32 *ecx, u32 *edx, bool exact_only);
31 
32 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu);
33 
cpuid_maxphyaddr(struct kvm_vcpu * vcpu)34 static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
35 {
36 	return vcpu->arch.maxphyaddr;
37 }
38 
kvm_vcpu_is_illegal_gpa(struct kvm_vcpu * vcpu,gpa_t gpa)39 static inline bool kvm_vcpu_is_illegal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
40 {
41 	return (gpa >= BIT_ULL(cpuid_maxphyaddr(vcpu)));
42 }
43 
44 struct cpuid_reg {
45 	u32 function;
46 	u32 index;
47 	int reg;
48 };
49 
50 static const struct cpuid_reg reverse_cpuid[] = {
51 	[CPUID_1_EDX]         = {         1, 0, CPUID_EDX},
52 	[CPUID_8000_0001_EDX] = {0x80000001, 0, CPUID_EDX},
53 	[CPUID_8086_0001_EDX] = {0x80860001, 0, CPUID_EDX},
54 	[CPUID_1_ECX]         = {         1, 0, CPUID_ECX},
55 	[CPUID_C000_0001_EDX] = {0xc0000001, 0, CPUID_EDX},
56 	[CPUID_8000_0001_ECX] = {0x80000001, 0, CPUID_ECX},
57 	[CPUID_7_0_EBX]       = {         7, 0, CPUID_EBX},
58 	[CPUID_D_1_EAX]       = {       0xd, 1, CPUID_EAX},
59 	[CPUID_8000_0008_EBX] = {0x80000008, 0, CPUID_EBX},
60 	[CPUID_6_EAX]         = {         6, 0, CPUID_EAX},
61 	[CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX},
62 	[CPUID_7_ECX]         = {         7, 0, CPUID_ECX},
63 	[CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
64 	[CPUID_7_EDX]         = {         7, 0, CPUID_EDX},
65 	[CPUID_7_1_EAX]       = {         7, 1, CPUID_EAX},
66 	[CPUID_8000_0021_EAX] = {0x80000021, 0, CPUID_EAX},
67 };
68 
69 /*
70  * Reverse CPUID and its derivatives can only be used for hardware-defined
71  * feature words, i.e. words whose bits directly correspond to a CPUID leaf.
72  * Retrieving a feature bit or masking guest CPUID from a Linux-defined word
73  * is nonsensical as the bit number/mask is an arbitrary software-defined value
74  * and can't be used by KVM to query/control guest capabilities.  And obviously
75  * the leaf being queried must have an entry in the lookup table.
76  */
reverse_cpuid_check(unsigned int x86_leaf)77 static __always_inline void reverse_cpuid_check(unsigned int x86_leaf)
78 {
79 	BUILD_BUG_ON(x86_leaf == CPUID_LNX_1);
80 	BUILD_BUG_ON(x86_leaf == CPUID_LNX_2);
81 	BUILD_BUG_ON(x86_leaf == CPUID_LNX_3);
82 	BUILD_BUG_ON(x86_leaf == CPUID_LNX_4);
83 	BUILD_BUG_ON(x86_leaf >= ARRAY_SIZE(reverse_cpuid));
84 	BUILD_BUG_ON(reverse_cpuid[x86_leaf].function == 0);
85 }
86 
87 /*
88  * Retrieve the bit mask from an X86_FEATURE_* definition.  Features contain
89  * the hardware defined bit number (stored in bits 4:0) and a software defined
90  * "word" (stored in bits 31:5).  The word is used to index into arrays of
91  * bit masks that hold the per-cpu feature capabilities, e.g. this_cpu_has().
92  */
__feature_bit(int x86_feature)93 static __always_inline u32 __feature_bit(int x86_feature)
94 {
95 	reverse_cpuid_check(x86_feature / 32);
96 	return 1 << (x86_feature & 31);
97 }
98 
99 #define feature_bit(name)  __feature_bit(X86_FEATURE_##name)
100 
x86_feature_cpuid(unsigned int x86_feature)101 static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned int x86_feature)
102 {
103 	unsigned int x86_leaf = x86_feature / 32;
104 
105 	reverse_cpuid_check(x86_leaf);
106 	return reverse_cpuid[x86_leaf];
107 }
108 
__cpuid_entry_get_reg(struct kvm_cpuid_entry2 * entry,u32 reg)109 static __always_inline u32 *__cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
110 						  u32 reg)
111 {
112 	switch (reg) {
113 	case CPUID_EAX:
114 		return &entry->eax;
115 	case CPUID_EBX:
116 		return &entry->ebx;
117 	case CPUID_ECX:
118 		return &entry->ecx;
119 	case CPUID_EDX:
120 		return &entry->edx;
121 	default:
122 		BUILD_BUG();
123 		return NULL;
124 	}
125 }
126 
cpuid_entry_get_reg(struct kvm_cpuid_entry2 * entry,unsigned int x86_feature)127 static __always_inline u32 *cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
128 						unsigned int x86_feature)
129 {
130 	const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
131 
132 	return __cpuid_entry_get_reg(entry, cpuid.reg);
133 }
134 
cpuid_entry_get(struct kvm_cpuid_entry2 * entry,unsigned int x86_feature)135 static __always_inline u32 cpuid_entry_get(struct kvm_cpuid_entry2 *entry,
136 					   unsigned int x86_feature)
137 {
138 	u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
139 
140 	return *reg & __feature_bit(x86_feature);
141 }
142 
cpuid_entry_has(struct kvm_cpuid_entry2 * entry,unsigned int x86_feature)143 static __always_inline bool cpuid_entry_has(struct kvm_cpuid_entry2 *entry,
144 					    unsigned int x86_feature)
145 {
146 	return cpuid_entry_get(entry, x86_feature);
147 }
148 
cpuid_entry_clear(struct kvm_cpuid_entry2 * entry,unsigned int x86_feature)149 static __always_inline void cpuid_entry_clear(struct kvm_cpuid_entry2 *entry,
150 					      unsigned int x86_feature)
151 {
152 	u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
153 
154 	*reg &= ~__feature_bit(x86_feature);
155 }
156 
cpuid_entry_set(struct kvm_cpuid_entry2 * entry,unsigned int x86_feature)157 static __always_inline void cpuid_entry_set(struct kvm_cpuid_entry2 *entry,
158 					    unsigned int x86_feature)
159 {
160 	u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
161 
162 	*reg |= __feature_bit(x86_feature);
163 }
164 
cpuid_entry_change(struct kvm_cpuid_entry2 * entry,unsigned int x86_feature,bool set)165 static __always_inline void cpuid_entry_change(struct kvm_cpuid_entry2 *entry,
166 					       unsigned int x86_feature,
167 					       bool set)
168 {
169 	u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
170 
171 	/*
172 	 * Open coded instead of using cpuid_entry_{clear,set}() to coerce the
173 	 * compiler into using CMOV instead of Jcc when possible.
174 	 */
175 	if (set)
176 		*reg |= __feature_bit(x86_feature);
177 	else
178 		*reg &= ~__feature_bit(x86_feature);
179 }
180 
cpuid_entry_override(struct kvm_cpuid_entry2 * entry,enum cpuid_leafs leaf)181 static __always_inline void cpuid_entry_override(struct kvm_cpuid_entry2 *entry,
182 						 enum cpuid_leafs leaf)
183 {
184 	u32 *reg = cpuid_entry_get_reg(entry, leaf * 32);
185 
186 	BUILD_BUG_ON(leaf >= ARRAY_SIZE(kvm_cpu_caps));
187 	*reg = kvm_cpu_caps[leaf];
188 }
189 
guest_cpuid_get_register(struct kvm_vcpu * vcpu,unsigned int x86_feature)190 static __always_inline u32 *guest_cpuid_get_register(struct kvm_vcpu *vcpu,
191 						     unsigned int x86_feature)
192 {
193 	const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
194 	struct kvm_cpuid_entry2 *entry;
195 
196 	entry = kvm_find_cpuid_entry(vcpu, cpuid.function, cpuid.index);
197 	if (!entry)
198 		return NULL;
199 
200 	return __cpuid_entry_get_reg(entry, cpuid.reg);
201 }
202 
guest_cpuid_has(struct kvm_vcpu * vcpu,unsigned int x86_feature)203 static __always_inline bool guest_cpuid_has(struct kvm_vcpu *vcpu,
204 					    unsigned int x86_feature)
205 {
206 	u32 *reg;
207 
208 	reg = guest_cpuid_get_register(vcpu, x86_feature);
209 	if (!reg)
210 		return false;
211 
212 	return *reg & __feature_bit(x86_feature);
213 }
214 
guest_cpuid_clear(struct kvm_vcpu * vcpu,unsigned int x86_feature)215 static __always_inline void guest_cpuid_clear(struct kvm_vcpu *vcpu,
216 					      unsigned int x86_feature)
217 {
218 	u32 *reg;
219 
220 	reg = guest_cpuid_get_register(vcpu, x86_feature);
221 	if (reg)
222 		*reg &= ~__feature_bit(x86_feature);
223 }
224 
guest_cpuid_is_amd_or_hygon(struct kvm_vcpu * vcpu)225 static inline bool guest_cpuid_is_amd_or_hygon(struct kvm_vcpu *vcpu)
226 {
227 	struct kvm_cpuid_entry2 *best;
228 
229 	best = kvm_find_cpuid_entry(vcpu, 0, 0);
230 	return best &&
231 	       (is_guest_vendor_amd(best->ebx, best->ecx, best->edx) ||
232 		is_guest_vendor_hygon(best->ebx, best->ecx, best->edx));
233 }
234 
guest_cpuid_family(struct kvm_vcpu * vcpu)235 static inline int guest_cpuid_family(struct kvm_vcpu *vcpu)
236 {
237 	struct kvm_cpuid_entry2 *best;
238 
239 	best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
240 	if (!best)
241 		return -1;
242 
243 	return x86_family(best->eax);
244 }
245 
guest_cpuid_model(struct kvm_vcpu * vcpu)246 static inline int guest_cpuid_model(struct kvm_vcpu *vcpu)
247 {
248 	struct kvm_cpuid_entry2 *best;
249 
250 	best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
251 	if (!best)
252 		return -1;
253 
254 	return x86_model(best->eax);
255 }
256 
guest_cpuid_stepping(struct kvm_vcpu * vcpu)257 static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu)
258 {
259 	struct kvm_cpuid_entry2 *best;
260 
261 	best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
262 	if (!best)
263 		return -1;
264 
265 	return x86_stepping(best->eax);
266 }
267 
guest_has_spec_ctrl_msr(struct kvm_vcpu * vcpu)268 static inline bool guest_has_spec_ctrl_msr(struct kvm_vcpu *vcpu)
269 {
270 	return (guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) ||
271 		guest_cpuid_has(vcpu, X86_FEATURE_AMD_STIBP) ||
272 		guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBRS) ||
273 		guest_cpuid_has(vcpu, X86_FEATURE_AMD_SSBD));
274 }
275 
guest_has_pred_cmd_msr(struct kvm_vcpu * vcpu)276 static inline bool guest_has_pred_cmd_msr(struct kvm_vcpu *vcpu)
277 {
278 	return (guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) ||
279 		guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBPB));
280 }
281 
supports_cpuid_fault(struct kvm_vcpu * vcpu)282 static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu)
283 {
284 	return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT;
285 }
286 
cpuid_fault_enabled(struct kvm_vcpu * vcpu)287 static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu)
288 {
289 	return vcpu->arch.msr_misc_features_enables &
290 		  MSR_MISC_FEATURES_ENABLES_CPUID_FAULT;
291 }
292 
kvm_cpu_cap_clear(unsigned int x86_feature)293 static __always_inline void kvm_cpu_cap_clear(unsigned int x86_feature)
294 {
295 	unsigned int x86_leaf = x86_feature / 32;
296 
297 	reverse_cpuid_check(x86_leaf);
298 	kvm_cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature);
299 }
300 
kvm_cpu_cap_set(unsigned int x86_feature)301 static __always_inline void kvm_cpu_cap_set(unsigned int x86_feature)
302 {
303 	unsigned int x86_leaf = x86_feature / 32;
304 
305 	reverse_cpuid_check(x86_leaf);
306 	kvm_cpu_caps[x86_leaf] |= __feature_bit(x86_feature);
307 }
308 
kvm_cpu_cap_get(unsigned int x86_feature)309 static __always_inline u32 kvm_cpu_cap_get(unsigned int x86_feature)
310 {
311 	unsigned int x86_leaf = x86_feature / 32;
312 
313 	reverse_cpuid_check(x86_leaf);
314 	return kvm_cpu_caps[x86_leaf] & __feature_bit(x86_feature);
315 }
316 
kvm_cpu_cap_has(unsigned int x86_feature)317 static __always_inline bool kvm_cpu_cap_has(unsigned int x86_feature)
318 {
319 	return !!kvm_cpu_cap_get(x86_feature);
320 }
321 
kvm_cpu_cap_check_and_set(unsigned int x86_feature)322 static __always_inline void kvm_cpu_cap_check_and_set(unsigned int x86_feature)
323 {
324 	if (boot_cpu_has(x86_feature))
325 		kvm_cpu_cap_set(x86_feature);
326 }
327 
page_address_valid(struct kvm_vcpu * vcpu,gpa_t gpa)328 static inline bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa)
329 {
330 	return PAGE_ALIGNED(gpa) && !(gpa >> cpuid_maxphyaddr(vcpu));
331 }
332 
guest_pv_has(struct kvm_vcpu * vcpu,unsigned int kvm_feature)333 static __always_inline bool guest_pv_has(struct kvm_vcpu *vcpu,
334 					 unsigned int kvm_feature)
335 {
336 	if (!vcpu->arch.pv_cpuid.enforce)
337 		return true;
338 
339 	return vcpu->arch.pv_cpuid.features & (1u << kvm_feature);
340 }
341 
342 #endif
343