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[mirror_ubuntu-bionic-kernel.git] / arch / x86 / kvm / cpuid.c
1 /*
2 * Kernel-based Virtual Machine driver for Linux
3 * cpuid support routines
4 *
5 * derived from arch/x86/kvm/x86.c
6 *
7 * Copyright 2011 Red Hat, Inc. and/or its affiliates.
8 * Copyright IBM Corporation, 2008
9 *
10 * This work is licensed under the terms of the GNU GPL, version 2. See
11 * the COPYING file in the top-level directory.
12 *
13 */
14
15 #include <linux/kvm_host.h>
16 #include <linux/export.h>
17 #include <linux/vmalloc.h>
18 #include <linux/uaccess.h>
19 #include <linux/sched/stat.h>
20
21 #include <asm/processor.h>
22 #include <asm/user.h>
23 #include <asm/fpu/xstate.h>
24 #include "cpuid.h"
25 #include "lapic.h"
26 #include "mmu.h"
27 #include "trace.h"
28 #include "pmu.h"
29
30 static u32 xstate_required_size(u64 xstate_bv, bool compacted)
31 {
32 int feature_bit = 0;
33 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
34
35 xstate_bv &= XFEATURE_MASK_EXTEND;
36 while (xstate_bv) {
37 if (xstate_bv & 0x1) {
38 u32 eax, ebx, ecx, edx, offset;
39 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
40 offset = compacted ? ret : ebx;
41 ret = max(ret, offset + eax);
42 }
43
44 xstate_bv >>= 1;
45 feature_bit++;
46 }
47
48 return ret;
49 }
50
51 bool kvm_mpx_supported(void)
52 {
53 return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR))
54 && kvm_x86_ops->mpx_supported());
55 }
56 EXPORT_SYMBOL_GPL(kvm_mpx_supported);
57
58 u64 kvm_supported_xcr0(void)
59 {
60 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
61
62 if (!kvm_mpx_supported())
63 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
64
65 return xcr0;
66 }
67
68 #define F(x) bit(X86_FEATURE_##x)
69
70 /* For scattered features from cpufeatures.h; we currently expose none */
71 #define KF(x) bit(KVM_CPUID_BIT_##x)
72
73 int kvm_update_cpuid(struct kvm_vcpu *vcpu)
74 {
75 struct kvm_cpuid_entry2 *best;
76 struct kvm_lapic *apic = vcpu->arch.apic;
77
78 best = kvm_find_cpuid_entry(vcpu, 1, 0);
79 if (!best)
80 return 0;
81
82 /* Update OSXSAVE bit */
83 if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) {
84 best->ecx &= ~F(OSXSAVE);
85 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
86 best->ecx |= F(OSXSAVE);
87 }
88
89 best->edx &= ~F(APIC);
90 if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE)
91 best->edx |= F(APIC);
92
93 if (apic) {
94 if (best->ecx & F(TSC_DEADLINE_TIMER))
95 apic->lapic_timer.timer_mode_mask = 3 << 17;
96 else
97 apic->lapic_timer.timer_mode_mask = 1 << 17;
98 }
99
100 best = kvm_find_cpuid_entry(vcpu, 7, 0);
101 if (best) {
102 /* Update OSPKE bit */
103 if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) {
104 best->ecx &= ~F(OSPKE);
105 if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE))
106 best->ecx |= F(OSPKE);
107 }
108 }
109
110 best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
111 if (!best) {
112 vcpu->arch.guest_supported_xcr0 = 0;
113 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
114 } else {
115 vcpu->arch.guest_supported_xcr0 =
116 (best->eax | ((u64)best->edx << 32)) &
117 kvm_supported_xcr0();
118 vcpu->arch.guest_xstate_size = best->ebx =
119 xstate_required_size(vcpu->arch.xcr0, false);
120 }
121
122 best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
123 if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
124 best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
125
126 /*
127 * The existing code assumes virtual address is 48-bit or 57-bit in the
128 * canonical address checks; exit if it is ever changed.
129 */
130 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
131 if (best) {
132 int vaddr_bits = (best->eax & 0xff00) >> 8;
133
134 if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
135 return -EINVAL;
136 }
137
138 /* Update physical-address width */
139 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
140 kvm_mmu_reset_context(vcpu);
141
142 kvm_pmu_refresh(vcpu);
143 return 0;
144 }
145
146 static int is_efer_nx(void)
147 {
148 unsigned long long efer = 0;
149
150 rdmsrl_safe(MSR_EFER, &efer);
151 return efer & EFER_NX;
152 }
153
154 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
155 {
156 int i;
157 struct kvm_cpuid_entry2 *e, *entry;
158
159 entry = NULL;
160 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
161 e = &vcpu->arch.cpuid_entries[i];
162 if (e->function == 0x80000001) {
163 entry = e;
164 break;
165 }
166 }
167 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
168 entry->edx &= ~F(NX);
169 printk(KERN_INFO "kvm: guest NX capability removed\n");
170 }
171 }
172
173 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
174 {
175 struct kvm_cpuid_entry2 *best;
176
177 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
178 if (!best || best->eax < 0x80000008)
179 goto not_found;
180 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
181 if (best)
182 return best->eax & 0xff;
183 not_found:
184 return 36;
185 }
186 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
187
188 /* when an old userspace process fills a new kernel module */
189 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
190 struct kvm_cpuid *cpuid,
191 struct kvm_cpuid_entry __user *entries)
192 {
193 int r, i;
194 struct kvm_cpuid_entry *cpuid_entries = NULL;
195
196 r = -E2BIG;
197 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
198 goto out;
199 r = -ENOMEM;
200 if (cpuid->nent) {
201 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) *
202 cpuid->nent);
203 if (!cpuid_entries)
204 goto out;
205 r = -EFAULT;
206 if (copy_from_user(cpuid_entries, entries,
207 cpuid->nent * sizeof(struct kvm_cpuid_entry)))
208 goto out;
209 }
210 for (i = 0; i < cpuid->nent; i++) {
211 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
212 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
213 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
214 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
215 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
216 vcpu->arch.cpuid_entries[i].index = 0;
217 vcpu->arch.cpuid_entries[i].flags = 0;
218 vcpu->arch.cpuid_entries[i].padding[0] = 0;
219 vcpu->arch.cpuid_entries[i].padding[1] = 0;
220 vcpu->arch.cpuid_entries[i].padding[2] = 0;
221 }
222 vcpu->arch.cpuid_nent = cpuid->nent;
223 cpuid_fix_nx_cap(vcpu);
224 kvm_apic_set_version(vcpu);
225 kvm_x86_ops->cpuid_update(vcpu);
226 r = kvm_update_cpuid(vcpu);
227
228 out:
229 vfree(cpuid_entries);
230 return r;
231 }
232
233 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
234 struct kvm_cpuid2 *cpuid,
235 struct kvm_cpuid_entry2 __user *entries)
236 {
237 int r;
238
239 r = -E2BIG;
240 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
241 goto out;
242 r = -EFAULT;
243 if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
244 cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
245 goto out;
246 vcpu->arch.cpuid_nent = cpuid->nent;
247 kvm_apic_set_version(vcpu);
248 kvm_x86_ops->cpuid_update(vcpu);
249 r = kvm_update_cpuid(vcpu);
250 out:
251 return r;
252 }
253
254 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
255 struct kvm_cpuid2 *cpuid,
256 struct kvm_cpuid_entry2 __user *entries)
257 {
258 int r;
259
260 r = -E2BIG;
261 if (cpuid->nent < vcpu->arch.cpuid_nent)
262 goto out;
263 r = -EFAULT;
264 if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
265 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
266 goto out;
267 return 0;
268
269 out:
270 cpuid->nent = vcpu->arch.cpuid_nent;
271 return r;
272 }
273
274 static void cpuid_mask(u32 *word, int wordnum)
275 {
276 *word &= boot_cpu_data.x86_capability[wordnum];
277 }
278
279 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
280 u32 index)
281 {
282 entry->function = function;
283 entry->index = index;
284 cpuid_count(entry->function, entry->index,
285 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
286 entry->flags = 0;
287 }
288
289 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
290 u32 func, u32 index, int *nent, int maxnent)
291 {
292 switch (func) {
293 case 0:
294 entry->eax = 1; /* only one leaf currently */
295 ++*nent;
296 break;
297 case 1:
298 entry->ecx = F(MOVBE);
299 ++*nent;
300 break;
301 default:
302 break;
303 }
304
305 entry->function = func;
306 entry->index = index;
307
308 return 0;
309 }
310
311 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
312 u32 index, int *nent, int maxnent)
313 {
314 int r;
315 unsigned f_nx = is_efer_nx() ? F(NX) : 0;
316 #ifdef CONFIG_X86_64
317 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
318 ? F(GBPAGES) : 0;
319 unsigned f_lm = F(LM);
320 #else
321 unsigned f_gbpages = 0;
322 unsigned f_lm = 0;
323 #endif
324 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
325 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
326 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
327 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
328
329 /* cpuid 1.edx */
330 const u32 kvm_cpuid_1_edx_x86_features =
331 F(FPU) | F(VME) | F(DE) | F(PSE) |
332 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
333 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
334 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
335 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
336 0 /* Reserved, DS, ACPI */ | F(MMX) |
337 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
338 0 /* HTT, TM, Reserved, PBE */;
339 /* cpuid 0x80000001.edx */
340 const u32 kvm_cpuid_8000_0001_edx_x86_features =
341 F(FPU) | F(VME) | F(DE) | F(PSE) |
342 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
343 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
344 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
345 F(PAT) | F(PSE36) | 0 /* Reserved */ |
346 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
347 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
348 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
349 /* cpuid 1.ecx */
350 const u32 kvm_cpuid_1_ecx_x86_features =
351 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
352 * but *not* advertised to guests via CPUID ! */
353 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
354 0 /* DS-CPL, VMX, SMX, EST */ |
355 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
356 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
357 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
358 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
359 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
360 F(F16C) | F(RDRAND);
361 /* cpuid 0x80000001.ecx */
362 const u32 kvm_cpuid_8000_0001_ecx_x86_features =
363 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
364 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
365 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
366 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
367
368 /* cpuid 0x80000008.ebx */
369 const u32 kvm_cpuid_8000_0008_ebx_x86_features =
370 F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
371 F(AMD_SSB_NO) | F(AMD_STIBP);
372
373 /* cpuid 0xC0000001.edx */
374 const u32 kvm_cpuid_C000_0001_edx_x86_features =
375 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
376 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
377 F(PMM) | F(PMM_EN);
378
379 /* cpuid 7.0.ebx */
380 const u32 kvm_cpuid_7_0_ebx_x86_features =
381 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
382 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
383 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
384 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) |
385 F(SHA_NI) | F(AVX512BW) | F(AVX512VL);
386
387 /* cpuid 0xD.1.eax */
388 const u32 kvm_cpuid_D_1_eax_x86_features =
389 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
390
391 /* cpuid 7.0.ecx*/
392 const u32 kvm_cpuid_7_0_ecx_x86_features =
393 F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ |
394 F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) |
395 F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG);
396
397 /* cpuid 7.0.edx*/
398 const u32 kvm_cpuid_7_0_edx_x86_features =
399 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
400 F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP);
401
402 /* all calls to cpuid_count() should be made on the same cpu */
403 get_cpu();
404
405 r = -E2BIG;
406
407 if (*nent >= maxnent)
408 goto out;
409
410 do_cpuid_1_ent(entry, function, index);
411 ++*nent;
412
413 switch (function) {
414 case 0:
415 entry->eax = min(entry->eax, (u32)0xd);
416 break;
417 case 1:
418 entry->edx &= kvm_cpuid_1_edx_x86_features;
419 cpuid_mask(&entry->edx, CPUID_1_EDX);
420 entry->ecx &= kvm_cpuid_1_ecx_x86_features;
421 cpuid_mask(&entry->ecx, CPUID_1_ECX);
422 /* we support x2apic emulation even if host does not support
423 * it since we emulate x2apic in software */
424 entry->ecx |= F(X2APIC);
425 break;
426 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
427 * may return different values. This forces us to get_cpu() before
428 * issuing the first command, and also to emulate this annoying behavior
429 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
430 case 2: {
431 int t, times = entry->eax & 0xff;
432
433 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
434 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
435 for (t = 1; t < times; ++t) {
436 if (*nent >= maxnent)
437 goto out;
438
439 do_cpuid_1_ent(&entry[t], function, 0);
440 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
441 ++*nent;
442 }
443 break;
444 }
445 /* function 4 has additional index. */
446 case 4: {
447 int i, cache_type;
448
449 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
450 /* read more entries until cache_type is zero */
451 for (i = 1; ; ++i) {
452 if (*nent >= maxnent)
453 goto out;
454
455 cache_type = entry[i - 1].eax & 0x1f;
456 if (!cache_type)
457 break;
458 do_cpuid_1_ent(&entry[i], function, i);
459 entry[i].flags |=
460 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
461 ++*nent;
462 }
463 break;
464 }
465 case 6: /* Thermal management */
466 entry->eax = 0x4; /* allow ARAT */
467 entry->ebx = 0;
468 entry->ecx = 0;
469 entry->edx = 0;
470 break;
471 case 7: {
472 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
473 /* Mask ebx against host capability word 9 */
474 if (index == 0) {
475 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features;
476 cpuid_mask(&entry->ebx, CPUID_7_0_EBX);
477 // TSC_ADJUST is emulated
478 entry->ebx |= F(TSC_ADJUST);
479 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
480 cpuid_mask(&entry->ecx, CPUID_7_ECX);
481 /* PKU is not yet implemented for shadow paging. */
482 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
483 entry->ecx &= ~F(PKU);
484 entry->edx &= kvm_cpuid_7_0_edx_x86_features;
485 cpuid_mask(&entry->edx, CPUID_7_EDX);
486 /*
487 * We emulate ARCH_CAPABILITIES in software even
488 * if the host doesn't support it.
489 */
490 entry->edx |= F(ARCH_CAPABILITIES);
491 } else {
492 entry->ebx = 0;
493 entry->ecx = 0;
494 entry->edx = 0;
495 }
496 entry->eax = 0;
497 break;
498 }
499 case 9:
500 break;
501 case 0xa: { /* Architectural Performance Monitoring */
502 struct x86_pmu_capability cap;
503 union cpuid10_eax eax;
504 union cpuid10_edx edx;
505
506 perf_get_x86_pmu_capability(&cap);
507
508 /*
509 * Only support guest architectural pmu on a host
510 * with architectural pmu.
511 */
512 if (!cap.version)
513 memset(&cap, 0, sizeof(cap));
514
515 eax.split.version_id = min(cap.version, 2);
516 eax.split.num_counters = cap.num_counters_gp;
517 eax.split.bit_width = cap.bit_width_gp;
518 eax.split.mask_length = cap.events_mask_len;
519
520 edx.split.num_counters_fixed = cap.num_counters_fixed;
521 edx.split.bit_width_fixed = cap.bit_width_fixed;
522 edx.split.reserved = 0;
523
524 entry->eax = eax.full;
525 entry->ebx = cap.events_mask;
526 entry->ecx = 0;
527 entry->edx = edx.full;
528 break;
529 }
530 /* function 0xb has additional index. */
531 case 0xb: {
532 int i, level_type;
533
534 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
535 /* read more entries until level_type is zero */
536 for (i = 1; ; ++i) {
537 if (*nent >= maxnent)
538 goto out;
539
540 level_type = entry[i - 1].ecx & 0xff00;
541 if (!level_type)
542 break;
543 do_cpuid_1_ent(&entry[i], function, i);
544 entry[i].flags |=
545 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
546 ++*nent;
547 }
548 break;
549 }
550 case 0xd: {
551 int idx, i;
552 u64 supported = kvm_supported_xcr0();
553
554 entry->eax &= supported;
555 entry->ebx = xstate_required_size(supported, false);
556 entry->ecx = entry->ebx;
557 entry->edx &= supported >> 32;
558 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
559 if (!supported)
560 break;
561
562 for (idx = 1, i = 1; idx < 64; ++idx) {
563 u64 mask = ((u64)1 << idx);
564 if (*nent >= maxnent)
565 goto out;
566
567 do_cpuid_1_ent(&entry[i], function, idx);
568 if (idx == 1) {
569 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
570 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
571 entry[i].ebx = 0;
572 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
573 entry[i].ebx =
574 xstate_required_size(supported,
575 true);
576 } else {
577 if (entry[i].eax == 0 || !(supported & mask))
578 continue;
579 if (WARN_ON_ONCE(entry[i].ecx & 1))
580 continue;
581 }
582 entry[i].ecx = 0;
583 entry[i].edx = 0;
584 entry[i].flags |=
585 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
586 ++*nent;
587 ++i;
588 }
589 break;
590 }
591 case KVM_CPUID_SIGNATURE: {
592 static const char signature[12] = "KVMKVMKVM\0\0";
593 const u32 *sigptr = (const u32 *)signature;
594 entry->eax = KVM_CPUID_FEATURES;
595 entry->ebx = sigptr[0];
596 entry->ecx = sigptr[1];
597 entry->edx = sigptr[2];
598 break;
599 }
600 case KVM_CPUID_FEATURES:
601 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
602 (1 << KVM_FEATURE_NOP_IO_DELAY) |
603 (1 << KVM_FEATURE_CLOCKSOURCE2) |
604 (1 << KVM_FEATURE_ASYNC_PF) |
605 (1 << KVM_FEATURE_PV_EOI) |
606 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
607 (1 << KVM_FEATURE_PV_UNHALT) |
608 (1 << KVM_FEATURE_ASYNC_PF_VMEXIT);
609
610 if (sched_info_on())
611 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
612
613 entry->ebx = 0;
614 entry->ecx = 0;
615 entry->edx = 0;
616 break;
617 case 0x80000000:
618 entry->eax = min(entry->eax, 0x8000001a);
619 break;
620 case 0x80000001:
621 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features;
622 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX);
623 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features;
624 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX);
625 break;
626 case 0x80000007: /* Advanced power management */
627 /* invariant TSC is CPUID.80000007H:EDX[8] */
628 entry->edx &= (1 << 8);
629 /* mask against host */
630 entry->edx &= boot_cpu_data.x86_power;
631 entry->eax = entry->ebx = entry->ecx = 0;
632 break;
633 case 0x80000008: {
634 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
635 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
636 unsigned phys_as = entry->eax & 0xff;
637
638 if (!g_phys_as)
639 g_phys_as = phys_as;
640 entry->eax = g_phys_as | (virt_as << 8);
641 entry->edx = 0;
642 /*
643 * IBRS, IBPB and VIRT_SSBD aren't necessarily present in
644 * hardware cpuid
645 */
646 if (boot_cpu_has(X86_FEATURE_AMD_IBPB))
647 entry->ebx |= F(AMD_IBPB);
648 if (boot_cpu_has(X86_FEATURE_AMD_IBRS))
649 entry->ebx |= F(AMD_IBRS);
650 if (boot_cpu_has(X86_FEATURE_VIRT_SSBD))
651 entry->ebx |= F(VIRT_SSBD);
652 entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
653 cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
654 /*
655 * The preference is to use SPEC CTRL MSR instead of the
656 * VIRT_SPEC MSR.
657 */
658 if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) &&
659 !boot_cpu_has(X86_FEATURE_AMD_SSBD))
660 entry->ebx |= F(VIRT_SSBD);
661 break;
662 }
663 case 0x80000019:
664 entry->ecx = entry->edx = 0;
665 break;
666 case 0x8000001a:
667 break;
668 case 0x8000001d:
669 break;
670 /*Add support for Centaur's CPUID instruction*/
671 case 0xC0000000:
672 /*Just support up to 0xC0000004 now*/
673 entry->eax = min(entry->eax, 0xC0000004);
674 break;
675 case 0xC0000001:
676 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features;
677 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX);
678 break;
679 case 3: /* Processor serial number */
680 case 5: /* MONITOR/MWAIT */
681 case 0xC0000002:
682 case 0xC0000003:
683 case 0xC0000004:
684 default:
685 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
686 break;
687 }
688
689 kvm_x86_ops->set_supported_cpuid(function, entry);
690
691 r = 0;
692
693 out:
694 put_cpu();
695
696 return r;
697 }
698
699 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
700 u32 idx, int *nent, int maxnent, unsigned int type)
701 {
702 if (type == KVM_GET_EMULATED_CPUID)
703 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
704
705 return __do_cpuid_ent(entry, func, idx, nent, maxnent);
706 }
707
708 #undef F
709
710 struct kvm_cpuid_param {
711 u32 func;
712 u32 idx;
713 bool has_leaf_count;
714 bool (*qualifier)(const struct kvm_cpuid_param *param);
715 };
716
717 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
718 {
719 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
720 }
721
722 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
723 __u32 num_entries, unsigned int ioctl_type)
724 {
725 int i;
726 __u32 pad[3];
727
728 if (ioctl_type != KVM_GET_EMULATED_CPUID)
729 return false;
730
731 /*
732 * We want to make sure that ->padding is being passed clean from
733 * userspace in case we want to use it for something in the future.
734 *
735 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
736 * have to give ourselves satisfied only with the emulated side. /me
737 * sheds a tear.
738 */
739 for (i = 0; i < num_entries; i++) {
740 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
741 return true;
742
743 if (pad[0] || pad[1] || pad[2])
744 return true;
745 }
746 return false;
747 }
748
749 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
750 struct kvm_cpuid_entry2 __user *entries,
751 unsigned int type)
752 {
753 struct kvm_cpuid_entry2 *cpuid_entries;
754 int limit, nent = 0, r = -E2BIG, i;
755 u32 func;
756 static const struct kvm_cpuid_param param[] = {
757 { .func = 0, .has_leaf_count = true },
758 { .func = 0x80000000, .has_leaf_count = true },
759 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
760 { .func = KVM_CPUID_SIGNATURE },
761 { .func = KVM_CPUID_FEATURES },
762 };
763
764 if (cpuid->nent < 1)
765 goto out;
766 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
767 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
768
769 if (sanity_check_entries(entries, cpuid->nent, type))
770 return -EINVAL;
771
772 r = -ENOMEM;
773 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
774 if (!cpuid_entries)
775 goto out;
776
777 r = 0;
778 for (i = 0; i < ARRAY_SIZE(param); i++) {
779 const struct kvm_cpuid_param *ent = &param[i];
780
781 if (ent->qualifier && !ent->qualifier(ent))
782 continue;
783
784 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
785 &nent, cpuid->nent, type);
786
787 if (r)
788 goto out_free;
789
790 if (!ent->has_leaf_count)
791 continue;
792
793 limit = cpuid_entries[nent - 1].eax;
794 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
795 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
796 &nent, cpuid->nent, type);
797
798 if (r)
799 goto out_free;
800 }
801
802 r = -EFAULT;
803 if (copy_to_user(entries, cpuid_entries,
804 nent * sizeof(struct kvm_cpuid_entry2)))
805 goto out_free;
806 cpuid->nent = nent;
807 r = 0;
808
809 out_free:
810 vfree(cpuid_entries);
811 out:
812 return r;
813 }
814
815 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
816 {
817 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
818 struct kvm_cpuid_entry2 *ej;
819 int j = i;
820 int nent = vcpu->arch.cpuid_nent;
821
822 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
823 /* when no next entry is found, the current entry[i] is reselected */
824 do {
825 j = (j + 1) % nent;
826 ej = &vcpu->arch.cpuid_entries[j];
827 } while (ej->function != e->function);
828
829 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
830
831 return j;
832 }
833
834 /* find an entry with matching function, matching index (if needed), and that
835 * should be read next (if it's stateful) */
836 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
837 u32 function, u32 index)
838 {
839 if (e->function != function)
840 return 0;
841 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
842 return 0;
843 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
844 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
845 return 0;
846 return 1;
847 }
848
849 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
850 u32 function, u32 index)
851 {
852 int i;
853 struct kvm_cpuid_entry2 *best = NULL;
854
855 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
856 struct kvm_cpuid_entry2 *e;
857
858 e = &vcpu->arch.cpuid_entries[i];
859 if (is_matching_cpuid_entry(e, function, index)) {
860 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
861 move_to_next_stateful_cpuid_entry(vcpu, i);
862 best = e;
863 break;
864 }
865 }
866 return best;
867 }
868 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
869
870 /*
871 * If no match is found, check whether we exceed the vCPU's limit
872 * and return the content of the highest valid _standard_ leaf instead.
873 * This is to satisfy the CPUID specification.
874 */
875 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
876 u32 function, u32 index)
877 {
878 struct kvm_cpuid_entry2 *maxlevel;
879
880 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
881 if (!maxlevel || maxlevel->eax >= function)
882 return NULL;
883 if (function & 0x80000000) {
884 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
885 if (!maxlevel)
886 return NULL;
887 }
888 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
889 }
890
891 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
892 u32 *ecx, u32 *edx, bool check_limit)
893 {
894 u32 function = *eax, index = *ecx;
895 struct kvm_cpuid_entry2 *best;
896 bool entry_found = true;
897
898 best = kvm_find_cpuid_entry(vcpu, function, index);
899
900 if (!best) {
901 entry_found = false;
902 if (!check_limit)
903 goto out;
904
905 best = check_cpuid_limit(vcpu, function, index);
906 }
907
908 out:
909 if (best) {
910 *eax = best->eax;
911 *ebx = best->ebx;
912 *ecx = best->ecx;
913 *edx = best->edx;
914 } else
915 *eax = *ebx = *ecx = *edx = 0;
916 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found);
917 return entry_found;
918 }
919 EXPORT_SYMBOL_GPL(kvm_cpuid);
920
921 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
922 {
923 u32 eax, ebx, ecx, edx;
924
925 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0))
926 return 1;
927
928 eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
929 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
930 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true);
931 kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
932 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
933 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
934 kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
935 return kvm_skip_emulated_instruction(vcpu);
936 }
937 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
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