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KVM: x86: support XSAVES usage in the host
[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/module.h>
17 #include <linux/vmalloc.h>
18 #include <linux/uaccess.h>
19 #include <asm/user.h>
20 #include <asm/xsave.h>
21 #include "cpuid.h"
22 #include "lapic.h"
23 #include "mmu.h"
24 #include "trace.h"
25
26 static u32 xstate_required_size(u64 xstate_bv)
27 {
28 int feature_bit = 0;
29 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
30
31 xstate_bv &= XSTATE_EXTEND_MASK;
32 while (xstate_bv) {
33 if (xstate_bv & 0x1) {
34 u32 eax, ebx, ecx, edx;
35 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
36 ret = max(ret, eax + ebx);
37 }
38
39 xstate_bv >>= 1;
40 feature_bit++;
41 }
42
43 return ret;
44 }
45
46 u64 kvm_supported_xcr0(void)
47 {
48 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
49
50 if (!kvm_x86_ops->mpx_supported())
51 xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR);
52
53 return xcr0;
54 }
55
56 int kvm_update_cpuid(struct kvm_vcpu *vcpu)
57 {
58 struct kvm_cpuid_entry2 *best;
59 struct kvm_lapic *apic = vcpu->arch.apic;
60
61 best = kvm_find_cpuid_entry(vcpu, 1, 0);
62 if (!best)
63 return 0;
64
65 /* Update OSXSAVE bit */
66 if (cpu_has_xsave && best->function == 0x1) {
67 best->ecx &= ~(bit(X86_FEATURE_OSXSAVE));
68 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
69 best->ecx |= bit(X86_FEATURE_OSXSAVE);
70 }
71
72 if (apic) {
73 if (best->ecx & bit(X86_FEATURE_TSC_DEADLINE_TIMER))
74 apic->lapic_timer.timer_mode_mask = 3 << 17;
75 else
76 apic->lapic_timer.timer_mode_mask = 1 << 17;
77 }
78
79 best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
80 if (!best) {
81 vcpu->arch.guest_supported_xcr0 = 0;
82 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
83 } else {
84 vcpu->arch.guest_supported_xcr0 =
85 (best->eax | ((u64)best->edx << 32)) &
86 kvm_supported_xcr0();
87 vcpu->arch.guest_xstate_size = best->ebx =
88 xstate_required_size(vcpu->arch.xcr0);
89 }
90
91 /*
92 * The existing code assumes virtual address is 48-bit in the canonical
93 * address checks; exit if it is ever changed.
94 */
95 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
96 if (best && ((best->eax & 0xff00) >> 8) != 48 &&
97 ((best->eax & 0xff00) >> 8) != 0)
98 return -EINVAL;
99
100 kvm_pmu_cpuid_update(vcpu);
101 return 0;
102 }
103
104 static int is_efer_nx(void)
105 {
106 unsigned long long efer = 0;
107
108 rdmsrl_safe(MSR_EFER, &efer);
109 return efer & EFER_NX;
110 }
111
112 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
113 {
114 int i;
115 struct kvm_cpuid_entry2 *e, *entry;
116
117 entry = NULL;
118 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
119 e = &vcpu->arch.cpuid_entries[i];
120 if (e->function == 0x80000001) {
121 entry = e;
122 break;
123 }
124 }
125 if (entry && (entry->edx & bit(X86_FEATURE_NX)) && !is_efer_nx()) {
126 entry->edx &= ~bit(X86_FEATURE_NX);
127 printk(KERN_INFO "kvm: guest NX capability removed\n");
128 }
129 }
130
131 /* when an old userspace process fills a new kernel module */
132 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
133 struct kvm_cpuid *cpuid,
134 struct kvm_cpuid_entry __user *entries)
135 {
136 int r, i;
137 struct kvm_cpuid_entry *cpuid_entries;
138
139 r = -E2BIG;
140 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
141 goto out;
142 r = -ENOMEM;
143 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent);
144 if (!cpuid_entries)
145 goto out;
146 r = -EFAULT;
147 if (copy_from_user(cpuid_entries, entries,
148 cpuid->nent * sizeof(struct kvm_cpuid_entry)))
149 goto out_free;
150 for (i = 0; i < cpuid->nent; i++) {
151 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
152 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
153 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
154 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
155 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
156 vcpu->arch.cpuid_entries[i].index = 0;
157 vcpu->arch.cpuid_entries[i].flags = 0;
158 vcpu->arch.cpuid_entries[i].padding[0] = 0;
159 vcpu->arch.cpuid_entries[i].padding[1] = 0;
160 vcpu->arch.cpuid_entries[i].padding[2] = 0;
161 }
162 vcpu->arch.cpuid_nent = cpuid->nent;
163 cpuid_fix_nx_cap(vcpu);
164 kvm_apic_set_version(vcpu);
165 kvm_x86_ops->cpuid_update(vcpu);
166 r = kvm_update_cpuid(vcpu);
167
168 out_free:
169 vfree(cpuid_entries);
170 out:
171 return r;
172 }
173
174 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
175 struct kvm_cpuid2 *cpuid,
176 struct kvm_cpuid_entry2 __user *entries)
177 {
178 int r;
179
180 r = -E2BIG;
181 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
182 goto out;
183 r = -EFAULT;
184 if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
185 cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
186 goto out;
187 vcpu->arch.cpuid_nent = cpuid->nent;
188 kvm_apic_set_version(vcpu);
189 kvm_x86_ops->cpuid_update(vcpu);
190 r = kvm_update_cpuid(vcpu);
191 out:
192 return r;
193 }
194
195 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
196 struct kvm_cpuid2 *cpuid,
197 struct kvm_cpuid_entry2 __user *entries)
198 {
199 int r;
200
201 r = -E2BIG;
202 if (cpuid->nent < vcpu->arch.cpuid_nent)
203 goto out;
204 r = -EFAULT;
205 if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
206 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
207 goto out;
208 return 0;
209
210 out:
211 cpuid->nent = vcpu->arch.cpuid_nent;
212 return r;
213 }
214
215 static void cpuid_mask(u32 *word, int wordnum)
216 {
217 *word &= boot_cpu_data.x86_capability[wordnum];
218 }
219
220 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
221 u32 index)
222 {
223 entry->function = function;
224 entry->index = index;
225 cpuid_count(entry->function, entry->index,
226 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
227 entry->flags = 0;
228 }
229
230 #define F(x) bit(X86_FEATURE_##x)
231
232 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
233 u32 func, u32 index, int *nent, int maxnent)
234 {
235 switch (func) {
236 case 0:
237 entry->eax = 1; /* only one leaf currently */
238 ++*nent;
239 break;
240 case 1:
241 entry->ecx = F(MOVBE);
242 ++*nent;
243 break;
244 default:
245 break;
246 }
247
248 entry->function = func;
249 entry->index = index;
250
251 return 0;
252 }
253
254 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
255 u32 index, int *nent, int maxnent)
256 {
257 int r;
258 unsigned f_nx = is_efer_nx() ? F(NX) : 0;
259 #ifdef CONFIG_X86_64
260 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
261 ? F(GBPAGES) : 0;
262 unsigned f_lm = F(LM);
263 #else
264 unsigned f_gbpages = 0;
265 unsigned f_lm = 0;
266 #endif
267 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
268 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
269 unsigned f_mpx = kvm_x86_ops->mpx_supported() ? F(MPX) : 0;
270
271 /* cpuid 1.edx */
272 const u32 kvm_supported_word0_x86_features =
273 F(FPU) | F(VME) | F(DE) | F(PSE) |
274 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
275 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
276 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
277 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
278 0 /* Reserved, DS, ACPI */ | F(MMX) |
279 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
280 0 /* HTT, TM, Reserved, PBE */;
281 /* cpuid 0x80000001.edx */
282 const u32 kvm_supported_word1_x86_features =
283 F(FPU) | F(VME) | F(DE) | F(PSE) |
284 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
285 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
286 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
287 F(PAT) | F(PSE36) | 0 /* Reserved */ |
288 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
289 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
290 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
291 /* cpuid 1.ecx */
292 const u32 kvm_supported_word4_x86_features =
293 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
294 * but *not* advertised to guests via CPUID ! */
295 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
296 0 /* DS-CPL, VMX, SMX, EST */ |
297 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
298 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
299 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
300 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
301 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
302 F(F16C) | F(RDRAND);
303 /* cpuid 0x80000001.ecx */
304 const u32 kvm_supported_word6_x86_features =
305 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
306 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
307 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
308 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
309
310 /* cpuid 0xC0000001.edx */
311 const u32 kvm_supported_word5_x86_features =
312 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
313 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
314 F(PMM) | F(PMM_EN);
315
316 /* cpuid 7.0.ebx */
317 const u32 kvm_supported_word9_x86_features =
318 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
319 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
320 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) |
321 F(AVX512CD);
322
323 /* cpuid 0xD.1.eax */
324 const u32 kvm_supported_word10_x86_features =
325 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1);
326
327 /* all calls to cpuid_count() should be made on the same cpu */
328 get_cpu();
329
330 r = -E2BIG;
331
332 if (*nent >= maxnent)
333 goto out;
334
335 do_cpuid_1_ent(entry, function, index);
336 ++*nent;
337
338 switch (function) {
339 case 0:
340 entry->eax = min(entry->eax, (u32)0xd);
341 break;
342 case 1:
343 entry->edx &= kvm_supported_word0_x86_features;
344 cpuid_mask(&entry->edx, 0);
345 entry->ecx &= kvm_supported_word4_x86_features;
346 cpuid_mask(&entry->ecx, 4);
347 /* we support x2apic emulation even if host does not support
348 * it since we emulate x2apic in software */
349 entry->ecx |= F(X2APIC);
350 break;
351 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
352 * may return different values. This forces us to get_cpu() before
353 * issuing the first command, and also to emulate this annoying behavior
354 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
355 case 2: {
356 int t, times = entry->eax & 0xff;
357
358 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
359 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
360 for (t = 1; t < times; ++t) {
361 if (*nent >= maxnent)
362 goto out;
363
364 do_cpuid_1_ent(&entry[t], function, 0);
365 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
366 ++*nent;
367 }
368 break;
369 }
370 /* function 4 has additional index. */
371 case 4: {
372 int i, cache_type;
373
374 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
375 /* read more entries until cache_type is zero */
376 for (i = 1; ; ++i) {
377 if (*nent >= maxnent)
378 goto out;
379
380 cache_type = entry[i - 1].eax & 0x1f;
381 if (!cache_type)
382 break;
383 do_cpuid_1_ent(&entry[i], function, i);
384 entry[i].flags |=
385 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
386 ++*nent;
387 }
388 break;
389 }
390 case 7: {
391 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
392 /* Mask ebx against host capability word 9 */
393 if (index == 0) {
394 entry->ebx &= kvm_supported_word9_x86_features;
395 cpuid_mask(&entry->ebx, 9);
396 // TSC_ADJUST is emulated
397 entry->ebx |= F(TSC_ADJUST);
398 } else
399 entry->ebx = 0;
400 entry->eax = 0;
401 entry->ecx = 0;
402 entry->edx = 0;
403 break;
404 }
405 case 9:
406 break;
407 case 0xa: { /* Architectural Performance Monitoring */
408 struct x86_pmu_capability cap;
409 union cpuid10_eax eax;
410 union cpuid10_edx edx;
411
412 perf_get_x86_pmu_capability(&cap);
413
414 /*
415 * Only support guest architectural pmu on a host
416 * with architectural pmu.
417 */
418 if (!cap.version)
419 memset(&cap, 0, sizeof(cap));
420
421 eax.split.version_id = min(cap.version, 2);
422 eax.split.num_counters = cap.num_counters_gp;
423 eax.split.bit_width = cap.bit_width_gp;
424 eax.split.mask_length = cap.events_mask_len;
425
426 edx.split.num_counters_fixed = cap.num_counters_fixed;
427 edx.split.bit_width_fixed = cap.bit_width_fixed;
428 edx.split.reserved = 0;
429
430 entry->eax = eax.full;
431 entry->ebx = cap.events_mask;
432 entry->ecx = 0;
433 entry->edx = edx.full;
434 break;
435 }
436 /* function 0xb has additional index. */
437 case 0xb: {
438 int i, level_type;
439
440 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
441 /* read more entries until level_type is zero */
442 for (i = 1; ; ++i) {
443 if (*nent >= maxnent)
444 goto out;
445
446 level_type = entry[i - 1].ecx & 0xff00;
447 if (!level_type)
448 break;
449 do_cpuid_1_ent(&entry[i], function, i);
450 entry[i].flags |=
451 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
452 ++*nent;
453 }
454 break;
455 }
456 case 0xd: {
457 int idx, i;
458 u64 supported = kvm_supported_xcr0();
459
460 entry->eax &= supported;
461 entry->edx &= supported >> 32;
462 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
463 if (!supported)
464 break;
465
466 for (idx = 1, i = 1; idx < 64; ++idx) {
467 u64 mask = ((u64)1 << idx);
468 if (*nent >= maxnent)
469 goto out;
470
471 do_cpuid_1_ent(&entry[i], function, idx);
472 if (idx == 1)
473 entry[i].eax &= kvm_supported_word10_x86_features;
474 else if (entry[i].eax == 0 || !(supported & mask))
475 continue;
476 entry[i].flags |=
477 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
478 ++*nent;
479 ++i;
480 }
481 break;
482 }
483 case KVM_CPUID_SIGNATURE: {
484 static const char signature[12] = "KVMKVMKVM\0\0";
485 const u32 *sigptr = (const u32 *)signature;
486 entry->eax = KVM_CPUID_FEATURES;
487 entry->ebx = sigptr[0];
488 entry->ecx = sigptr[1];
489 entry->edx = sigptr[2];
490 break;
491 }
492 case KVM_CPUID_FEATURES:
493 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
494 (1 << KVM_FEATURE_NOP_IO_DELAY) |
495 (1 << KVM_FEATURE_CLOCKSOURCE2) |
496 (1 << KVM_FEATURE_ASYNC_PF) |
497 (1 << KVM_FEATURE_PV_EOI) |
498 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
499 (1 << KVM_FEATURE_PV_UNHALT);
500
501 if (sched_info_on())
502 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
503
504 entry->ebx = 0;
505 entry->ecx = 0;
506 entry->edx = 0;
507 break;
508 case 0x80000000:
509 entry->eax = min(entry->eax, 0x8000001a);
510 break;
511 case 0x80000001:
512 entry->edx &= kvm_supported_word1_x86_features;
513 cpuid_mask(&entry->edx, 1);
514 entry->ecx &= kvm_supported_word6_x86_features;
515 cpuid_mask(&entry->ecx, 6);
516 break;
517 case 0x80000007: /* Advanced power management */
518 /* invariant TSC is CPUID.80000007H:EDX[8] */
519 entry->edx &= (1 << 8);
520 /* mask against host */
521 entry->edx &= boot_cpu_data.x86_power;
522 entry->eax = entry->ebx = entry->ecx = 0;
523 break;
524 case 0x80000008: {
525 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
526 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
527 unsigned phys_as = entry->eax & 0xff;
528
529 if (!g_phys_as)
530 g_phys_as = phys_as;
531 entry->eax = g_phys_as | (virt_as << 8);
532 entry->ebx = entry->edx = 0;
533 break;
534 }
535 case 0x80000019:
536 entry->ecx = entry->edx = 0;
537 break;
538 case 0x8000001a:
539 break;
540 case 0x8000001d:
541 break;
542 /*Add support for Centaur's CPUID instruction*/
543 case 0xC0000000:
544 /*Just support up to 0xC0000004 now*/
545 entry->eax = min(entry->eax, 0xC0000004);
546 break;
547 case 0xC0000001:
548 entry->edx &= kvm_supported_word5_x86_features;
549 cpuid_mask(&entry->edx, 5);
550 break;
551 case 3: /* Processor serial number */
552 case 5: /* MONITOR/MWAIT */
553 case 6: /* Thermal management */
554 case 0xC0000002:
555 case 0xC0000003:
556 case 0xC0000004:
557 default:
558 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
559 break;
560 }
561
562 kvm_x86_ops->set_supported_cpuid(function, entry);
563
564 r = 0;
565
566 out:
567 put_cpu();
568
569 return r;
570 }
571
572 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
573 u32 idx, int *nent, int maxnent, unsigned int type)
574 {
575 if (type == KVM_GET_EMULATED_CPUID)
576 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
577
578 return __do_cpuid_ent(entry, func, idx, nent, maxnent);
579 }
580
581 #undef F
582
583 struct kvm_cpuid_param {
584 u32 func;
585 u32 idx;
586 bool has_leaf_count;
587 bool (*qualifier)(const struct kvm_cpuid_param *param);
588 };
589
590 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
591 {
592 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
593 }
594
595 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
596 __u32 num_entries, unsigned int ioctl_type)
597 {
598 int i;
599 __u32 pad[3];
600
601 if (ioctl_type != KVM_GET_EMULATED_CPUID)
602 return false;
603
604 /*
605 * We want to make sure that ->padding is being passed clean from
606 * userspace in case we want to use it for something in the future.
607 *
608 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
609 * have to give ourselves satisfied only with the emulated side. /me
610 * sheds a tear.
611 */
612 for (i = 0; i < num_entries; i++) {
613 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
614 return true;
615
616 if (pad[0] || pad[1] || pad[2])
617 return true;
618 }
619 return false;
620 }
621
622 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
623 struct kvm_cpuid_entry2 __user *entries,
624 unsigned int type)
625 {
626 struct kvm_cpuid_entry2 *cpuid_entries;
627 int limit, nent = 0, r = -E2BIG, i;
628 u32 func;
629 static const struct kvm_cpuid_param param[] = {
630 { .func = 0, .has_leaf_count = true },
631 { .func = 0x80000000, .has_leaf_count = true },
632 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
633 { .func = KVM_CPUID_SIGNATURE },
634 { .func = KVM_CPUID_FEATURES },
635 };
636
637 if (cpuid->nent < 1)
638 goto out;
639 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
640 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
641
642 if (sanity_check_entries(entries, cpuid->nent, type))
643 return -EINVAL;
644
645 r = -ENOMEM;
646 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
647 if (!cpuid_entries)
648 goto out;
649
650 r = 0;
651 for (i = 0; i < ARRAY_SIZE(param); i++) {
652 const struct kvm_cpuid_param *ent = &param[i];
653
654 if (ent->qualifier && !ent->qualifier(ent))
655 continue;
656
657 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
658 &nent, cpuid->nent, type);
659
660 if (r)
661 goto out_free;
662
663 if (!ent->has_leaf_count)
664 continue;
665
666 limit = cpuid_entries[nent - 1].eax;
667 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
668 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
669 &nent, cpuid->nent, type);
670
671 if (r)
672 goto out_free;
673 }
674
675 r = -EFAULT;
676 if (copy_to_user(entries, cpuid_entries,
677 nent * sizeof(struct kvm_cpuid_entry2)))
678 goto out_free;
679 cpuid->nent = nent;
680 r = 0;
681
682 out_free:
683 vfree(cpuid_entries);
684 out:
685 return r;
686 }
687
688 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
689 {
690 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
691 int j, nent = vcpu->arch.cpuid_nent;
692
693 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
694 /* when no next entry is found, the current entry[i] is reselected */
695 for (j = i + 1; ; j = (j + 1) % nent) {
696 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
697 if (ej->function == e->function) {
698 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
699 return j;
700 }
701 }
702 return 0; /* silence gcc, even though control never reaches here */
703 }
704
705 /* find an entry with matching function, matching index (if needed), and that
706 * should be read next (if it's stateful) */
707 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
708 u32 function, u32 index)
709 {
710 if (e->function != function)
711 return 0;
712 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
713 return 0;
714 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
715 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
716 return 0;
717 return 1;
718 }
719
720 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
721 u32 function, u32 index)
722 {
723 int i;
724 struct kvm_cpuid_entry2 *best = NULL;
725
726 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
727 struct kvm_cpuid_entry2 *e;
728
729 e = &vcpu->arch.cpuid_entries[i];
730 if (is_matching_cpuid_entry(e, function, index)) {
731 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
732 move_to_next_stateful_cpuid_entry(vcpu, i);
733 best = e;
734 break;
735 }
736 }
737 return best;
738 }
739 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
740
741 int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
742 {
743 struct kvm_cpuid_entry2 *best;
744
745 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
746 if (!best || best->eax < 0x80000008)
747 goto not_found;
748 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
749 if (best)
750 return best->eax & 0xff;
751 not_found:
752 return 36;
753 }
754 EXPORT_SYMBOL_GPL(cpuid_maxphyaddr);
755
756 /*
757 * If no match is found, check whether we exceed the vCPU's limit
758 * and return the content of the highest valid _standard_ leaf instead.
759 * This is to satisfy the CPUID specification.
760 */
761 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
762 u32 function, u32 index)
763 {
764 struct kvm_cpuid_entry2 *maxlevel;
765
766 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
767 if (!maxlevel || maxlevel->eax >= function)
768 return NULL;
769 if (function & 0x80000000) {
770 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
771 if (!maxlevel)
772 return NULL;
773 }
774 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
775 }
776
777 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
778 {
779 u32 function = *eax, index = *ecx;
780 struct kvm_cpuid_entry2 *best;
781
782 best = kvm_find_cpuid_entry(vcpu, function, index);
783
784 if (!best)
785 best = check_cpuid_limit(vcpu, function, index);
786
787 /*
788 * Perfmon not yet supported for L2 guest.
789 */
790 if (is_guest_mode(vcpu) && function == 0xa)
791 best = NULL;
792
793 if (best) {
794 *eax = best->eax;
795 *ebx = best->ebx;
796 *ecx = best->ecx;
797 *edx = best->edx;
798 } else
799 *eax = *ebx = *ecx = *edx = 0;
800 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx);
801 }
802 EXPORT_SYMBOL_GPL(kvm_cpuid);
803
804 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
805 {
806 u32 function, eax, ebx, ecx, edx;
807
808 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
809 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
810 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx);
811 kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
812 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
813 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
814 kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
815 kvm_x86_ops->skip_emulated_instruction(vcpu);
816 }
817 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
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