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-rw-r--r--arch/x86/kvm/cpuid.c670
1 files changed, 670 insertions, 0 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
new file mode 100644
index 000000000000..89b02bfaaca5
--- /dev/null
+++ b/arch/x86/kvm/cpuid.c
@@ -0,0 +1,670 @@
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
26void kvm_update_cpuid(struct kvm_vcpu *vcpu)
27{
28 struct kvm_cpuid_entry2 *best;
29 struct kvm_lapic *apic = vcpu->arch.apic;
30
31 best = kvm_find_cpuid_entry(vcpu, 1, 0);
32 if (!best)
33 return;
34
35 /* Update OSXSAVE bit */
36 if (cpu_has_xsave && best->function == 0x1) {
37 best->ecx &= ~(bit(X86_FEATURE_OSXSAVE));
38 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
39 best->ecx |= bit(X86_FEATURE_OSXSAVE);
40 }
41
42 if (apic) {
43 if (best->ecx & bit(X86_FEATURE_TSC_DEADLINE_TIMER))
44 apic->lapic_timer.timer_mode_mask = 3 << 17;
45 else
46 apic->lapic_timer.timer_mode_mask = 1 << 17;
47 }
48
49 kvm_pmu_cpuid_update(vcpu);
50}
51
52static int is_efer_nx(void)
53{
54 unsigned long long efer = 0;
55
56 rdmsrl_safe(MSR_EFER, &efer);
57 return efer & EFER_NX;
58}
59
60static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
61{
62 int i;
63 struct kvm_cpuid_entry2 *e, *entry;
64
65 entry = NULL;
66 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
67 e = &vcpu->arch.cpuid_entries[i];
68 if (e->function == 0x80000001) {
69 entry = e;
70 break;
71 }
72 }
73 if (entry && (entry->edx & (1 << 20)) && !is_efer_nx()) {
74 entry->edx &= ~(1 << 20);
75 printk(KERN_INFO "kvm: guest NX capability removed\n");
76 }
77}
78
79/* when an old userspace process fills a new kernel module */
80int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
81 struct kvm_cpuid *cpuid,
82 struct kvm_cpuid_entry __user *entries)
83{
84 int r, i;
85 struct kvm_cpuid_entry *cpuid_entries;
86
87 r = -E2BIG;
88 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
89 goto out;
90 r = -ENOMEM;
91 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent);
92 if (!cpuid_entries)
93 goto out;
94 r = -EFAULT;
95 if (copy_from_user(cpuid_entries, entries,
96 cpuid->nent * sizeof(struct kvm_cpuid_entry)))
97 goto out_free;
98 for (i = 0; i < cpuid->nent; i++) {
99 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
100 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
101 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
102 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
103 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
104 vcpu->arch.cpuid_entries[i].index = 0;
105 vcpu->arch.cpuid_entries[i].flags = 0;
106 vcpu->arch.cpuid_entries[i].padding[0] = 0;
107 vcpu->arch.cpuid_entries[i].padding[1] = 0;
108 vcpu->arch.cpuid_entries[i].padding[2] = 0;
109 }
110 vcpu->arch.cpuid_nent = cpuid->nent;
111 cpuid_fix_nx_cap(vcpu);
112 r = 0;
113 kvm_apic_set_version(vcpu);
114 kvm_x86_ops->cpuid_update(vcpu);
115 kvm_update_cpuid(vcpu);
116
117out_free:
118 vfree(cpuid_entries);
119out:
120 return r;
121}
122
123int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
124 struct kvm_cpuid2 *cpuid,
125 struct kvm_cpuid_entry2 __user *entries)
126{
127 int r;
128
129 r = -E2BIG;
130 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
131 goto out;
132 r = -EFAULT;
133 if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
134 cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
135 goto out;
136 vcpu->arch.cpuid_nent = cpuid->nent;
137 kvm_apic_set_version(vcpu);
138 kvm_x86_ops->cpuid_update(vcpu);
139 kvm_update_cpuid(vcpu);
140 return 0;
141
142out:
143 return r;
144}
145
146int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
147 struct kvm_cpuid2 *cpuid,
148 struct kvm_cpuid_entry2 __user *entries)
149{
150 int r;
151
152 r = -E2BIG;
153 if (cpuid->nent < vcpu->arch.cpuid_nent)
154 goto out;
155 r = -EFAULT;
156 if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
157 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
158 goto out;
159 return 0;
160
161out:
162 cpuid->nent = vcpu->arch.cpuid_nent;
163 return r;
164}
165
166static void cpuid_mask(u32 *word, int wordnum)
167{
168 *word &= boot_cpu_data.x86_capability[wordnum];
169}
170
171static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
172 u32 index)
173{
174 entry->function = function;
175 entry->index = index;
176 cpuid_count(entry->function, entry->index,
177 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
178 entry->flags = 0;
179}
180
181static bool supported_xcr0_bit(unsigned bit)
182{
183 u64 mask = ((u64)1 << bit);
184
185 return mask & (XSTATE_FP | XSTATE_SSE | XSTATE_YMM) & host_xcr0;
186}
187
188#define F(x) bit(X86_FEATURE_##x)
189
190static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
191 u32 index, int *nent, int maxnent)
192{
193 int r;
194 unsigned f_nx = is_efer_nx() ? F(NX) : 0;
195#ifdef CONFIG_X86_64
196 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
197 ? F(GBPAGES) : 0;
198 unsigned f_lm = F(LM);
199#else
200 unsigned f_gbpages = 0;
201 unsigned f_lm = 0;
202#endif
203 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
204
205 /* cpuid 1.edx */
206 const u32 kvm_supported_word0_x86_features =
207 F(FPU) | F(VME) | F(DE) | F(PSE) |
208 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
209 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
210 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
211 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLSH) |
212 0 /* Reserved, DS, ACPI */ | F(MMX) |
213 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
214 0 /* HTT, TM, Reserved, PBE */;
215 /* cpuid 0x80000001.edx */
216 const u32 kvm_supported_word1_x86_features =
217 F(FPU) | F(VME) | F(DE) | F(PSE) |
218 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
219 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
220 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
221 F(PAT) | F(PSE36) | 0 /* Reserved */ |
222 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
223 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
224 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
225 /* cpuid 1.ecx */
226 const u32 kvm_supported_word4_x86_features =
227 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
228 0 /* DS-CPL, VMX, SMX, EST */ |
229 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
230 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
231 0 /* Reserved, DCA */ | F(XMM4_1) |
232 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
233 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
234 F(F16C) | F(RDRAND);
235 /* cpuid 0x80000001.ecx */
236 const u32 kvm_supported_word6_x86_features =
237 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
238 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
239 F(3DNOWPREFETCH) | 0 /* OSVW */ | 0 /* IBS */ | F(XOP) |
240 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
241
242 /* cpuid 0xC0000001.edx */
243 const u32 kvm_supported_word5_x86_features =
244 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
245 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
246 F(PMM) | F(PMM_EN);
247
248 /* cpuid 7.0.ebx */
249 const u32 kvm_supported_word9_x86_features =
250 F(FSGSBASE) | F(BMI1) | F(AVX2) | F(SMEP) | F(BMI2) | F(ERMS);
251
252 /* all calls to cpuid_count() should be made on the same cpu */
253 get_cpu();
254
255 r = -E2BIG;
256
257 if (*nent >= maxnent)
258 goto out;
259
260 do_cpuid_1_ent(entry, function, index);
261 ++*nent;
262
263 switch (function) {
264 case 0:
265 entry->eax = min(entry->eax, (u32)0xd);
266 break;
267 case 1:
268 entry->edx &= kvm_supported_word0_x86_features;
269 cpuid_mask(&entry->edx, 0);
270 entry->ecx &= kvm_supported_word4_x86_features;
271 cpuid_mask(&entry->ecx, 4);
272 /* we support x2apic emulation even if host does not support
273 * it since we emulate x2apic in software */
274 entry->ecx |= F(X2APIC);
275 break;
276 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
277 * may return different values. This forces us to get_cpu() before
278 * issuing the first command, and also to emulate this annoying behavior
279 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
280 case 2: {
281 int t, times = entry->eax & 0xff;
282
283 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
284 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
285 for (t = 1; t < times; ++t) {
286 if (*nent >= maxnent)
287 goto out;
288
289 do_cpuid_1_ent(&entry[t], function, 0);
290 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
291 ++*nent;
292 }
293 break;
294 }
295 /* function 4 has additional index. */
296 case 4: {
297 int i, cache_type;
298
299 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
300 /* read more entries until cache_type is zero */
301 for (i = 1; ; ++i) {
302 if (*nent >= maxnent)
303 goto out;
304
305 cache_type = entry[i - 1].eax & 0x1f;
306 if (!cache_type)
307 break;
308 do_cpuid_1_ent(&entry[i], function, i);
309 entry[i].flags |=
310 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
311 ++*nent;
312 }
313 break;
314 }
315 case 7: {
316 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
317 /* Mask ebx against host capbability word 9 */
318 if (index == 0) {
319 entry->ebx &= kvm_supported_word9_x86_features;
320 cpuid_mask(&entry->ebx, 9);
321 } else
322 entry->ebx = 0;
323 entry->eax = 0;
324 entry->ecx = 0;
325 entry->edx = 0;
326 break;
327 }
328 case 9:
329 break;
330 case 0xa: { /* Architectural Performance Monitoring */
331 struct x86_pmu_capability cap;
332 union cpuid10_eax eax;
333 union cpuid10_edx edx;
334
335 perf_get_x86_pmu_capability(&cap);
336
337 /*
338 * Only support guest architectural pmu on a host
339 * with architectural pmu.
340 */
341 if (!cap.version)
342 memset(&cap, 0, sizeof(cap));
343
344 eax.split.version_id = min(cap.version, 2);
345 eax.split.num_counters = cap.num_counters_gp;
346 eax.split.bit_width = cap.bit_width_gp;
347 eax.split.mask_length = cap.events_mask_len;
348
349 edx.split.num_counters_fixed = cap.num_counters_fixed;
350 edx.split.bit_width_fixed = cap.bit_width_fixed;
351 edx.split.reserved = 0;
352
353 entry->eax = eax.full;
354 entry->ebx = cap.events_mask;
355 entry->ecx = 0;
356 entry->edx = edx.full;
357 break;
358 }
359 /* function 0xb has additional index. */
360 case 0xb: {
361 int i, level_type;
362
363 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
364 /* read more entries until level_type is zero */
365 for (i = 1; ; ++i) {
366 if (*nent >= maxnent)
367 goto out;
368
369 level_type = entry[i - 1].ecx & 0xff00;
370 if (!level_type)
371 break;
372 do_cpuid_1_ent(&entry[i], function, i);
373 entry[i].flags |=
374 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
375 ++*nent;
376 }
377 break;
378 }
379 case 0xd: {
380 int idx, i;
381
382 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
383 for (idx = 1, i = 1; idx < 64; ++idx) {
384 if (*nent >= maxnent)
385 goto out;
386
387 do_cpuid_1_ent(&entry[i], function, idx);
388 if (entry[i].eax == 0 || !supported_xcr0_bit(idx))
389 continue;
390 entry[i].flags |=
391 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
392 ++*nent;
393 ++i;
394 }
395 break;
396 }
397 case KVM_CPUID_SIGNATURE: {
398 char signature[12] = "KVMKVMKVM\0\0";
399 u32 *sigptr = (u32 *)signature;
400 entry->eax = 0;
401 entry->ebx = sigptr[0];
402 entry->ecx = sigptr[1];
403 entry->edx = sigptr[2];
404 break;
405 }
406 case KVM_CPUID_FEATURES:
407 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
408 (1 << KVM_FEATURE_NOP_IO_DELAY) |
409 (1 << KVM_FEATURE_CLOCKSOURCE2) |
410 (1 << KVM_FEATURE_ASYNC_PF) |
411 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT);
412
413 if (sched_info_on())
414 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
415
416 entry->ebx = 0;
417 entry->ecx = 0;
418 entry->edx = 0;
419 break;
420 case 0x80000000:
421 entry->eax = min(entry->eax, 0x8000001a);
422 break;
423 case 0x80000001:
424 entry->edx &= kvm_supported_word1_x86_features;
425 cpuid_mask(&entry->edx, 1);
426 entry->ecx &= kvm_supported_word6_x86_features;
427 cpuid_mask(&entry->ecx, 6);
428 break;
429 case 0x80000008: {
430 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
431 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
432 unsigned phys_as = entry->eax & 0xff;
433
434 if (!g_phys_as)
435 g_phys_as = phys_as;
436 entry->eax = g_phys_as | (virt_as << 8);
437 entry->ebx = entry->edx = 0;
438 break;
439 }
440 case 0x80000019:
441 entry->ecx = entry->edx = 0;
442 break;
443 case 0x8000001a:
444 break;
445 case 0x8000001d:
446 break;
447 /*Add support for Centaur's CPUID instruction*/
448 case 0xC0000000:
449 /*Just support up to 0xC0000004 now*/
450 entry->eax = min(entry->eax, 0xC0000004);
451 break;
452 case 0xC0000001:
453 entry->edx &= kvm_supported_word5_x86_features;
454 cpuid_mask(&entry->edx, 5);
455 break;
456 case 3: /* Processor serial number */
457 case 5: /* MONITOR/MWAIT */
458 case 6: /* Thermal management */
459 case 0x80000007: /* Advanced power management */
460 case 0xC0000002:
461 case 0xC0000003:
462 case 0xC0000004:
463 default:
464 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
465 break;
466 }
467
468 kvm_x86_ops->set_supported_cpuid(function, entry);
469
470 r = 0;
471
472out:
473 put_cpu();
474
475 return r;
476}
477
478#undef F
479
480struct kvm_cpuid_param {
481 u32 func;
482 u32 idx;
483 bool has_leaf_count;
484 bool (*qualifier)(struct kvm_cpuid_param *param);
485};
486
487static bool is_centaur_cpu(struct kvm_cpuid_param *param)
488{
489 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
490}
491
492int kvm_dev_ioctl_get_supported_cpuid(struct kvm_cpuid2 *cpuid,
493 struct kvm_cpuid_entry2 __user *entries)
494{
495 struct kvm_cpuid_entry2 *cpuid_entries;
496 int limit, nent = 0, r = -E2BIG, i;
497 u32 func;
498 static struct kvm_cpuid_param param[] = {
499 { .func = 0, .has_leaf_count = true },
500 { .func = 0x80000000, .has_leaf_count = true },
501 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
502 { .func = KVM_CPUID_SIGNATURE },
503 { .func = KVM_CPUID_FEATURES },
504 };
505
506 if (cpuid->nent < 1)
507 goto out;
508 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
509 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
510 r = -ENOMEM;
511 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
512 if (!cpuid_entries)
513 goto out;
514
515 r = 0;
516 for (i = 0; i < ARRAY_SIZE(param); i++) {
517 struct kvm_cpuid_param *ent = &param[i];
518
519 if (ent->qualifier && !ent->qualifier(ent))
520 continue;
521
522 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
523 &nent, cpuid->nent);
524
525 if (r)
526 goto out_free;
527
528 if (!ent->has_leaf_count)
529 continue;
530
531 limit = cpuid_entries[nent - 1].eax;
532 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
533 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
534 &nent, cpuid->nent);
535
536 if (r)
537 goto out_free;
538 }
539
540 r = -EFAULT;
541 if (copy_to_user(entries, cpuid_entries,
542 nent * sizeof(struct kvm_cpuid_entry2)))
543 goto out_free;
544 cpuid->nent = nent;
545 r = 0;
546
547out_free:
548 vfree(cpuid_entries);
549out:
550 return r;
551}
552
553static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
554{
555 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
556 int j, nent = vcpu->arch.cpuid_nent;
557
558 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
559 /* when no next entry is found, the current entry[i] is reselected */
560 for (j = i + 1; ; j = (j + 1) % nent) {
561 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
562 if (ej->function == e->function) {
563 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
564 return j;
565 }
566 }
567 return 0; /* silence gcc, even though control never reaches here */
568}
569
570/* find an entry with matching function, matching index (if needed), and that
571 * should be read next (if it's stateful) */
572static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
573 u32 function, u32 index)
574{
575 if (e->function != function)
576 return 0;
577 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
578 return 0;
579 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
580 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
581 return 0;
582 return 1;
583}
584
585struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
586 u32 function, u32 index)
587{
588 int i;
589 struct kvm_cpuid_entry2 *best = NULL;
590
591 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
592 struct kvm_cpuid_entry2 *e;
593
594 e = &vcpu->arch.cpuid_entries[i];
595 if (is_matching_cpuid_entry(e, function, index)) {
596 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
597 move_to_next_stateful_cpuid_entry(vcpu, i);
598 best = e;
599 break;
600 }
601 }
602 return best;
603}
604EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
605
606int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
607{
608 struct kvm_cpuid_entry2 *best;
609
610 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
611 if (!best || best->eax < 0x80000008)
612 goto not_found;
613 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
614 if (best)
615 return best->eax & 0xff;
616not_found:
617 return 36;
618}
619
620/*
621 * If no match is found, check whether we exceed the vCPU's limit
622 * and return the content of the highest valid _standard_ leaf instead.
623 * This is to satisfy the CPUID specification.
624 */
625static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
626 u32 function, u32 index)
627{
628 struct kvm_cpuid_entry2 *maxlevel;
629
630 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
631 if (!maxlevel || maxlevel->eax >= function)
632 return NULL;
633 if (function & 0x80000000) {
634 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
635 if (!maxlevel)
636 return NULL;
637 }
638 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
639}
640
641void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
642{
643 u32 function, index;
644 struct kvm_cpuid_entry2 *best;
645
646 function = kvm_register_read(vcpu, VCPU_REGS_RAX);
647 index = kvm_register_read(vcpu, VCPU_REGS_RCX);
648 kvm_register_write(vcpu, VCPU_REGS_RAX, 0);
649 kvm_register_write(vcpu, VCPU_REGS_RBX, 0);
650 kvm_register_write(vcpu, VCPU_REGS_RCX, 0);
651 kvm_register_write(vcpu, VCPU_REGS_RDX, 0);
652 best = kvm_find_cpuid_entry(vcpu, function, index);
653
654 if (!best)
655 best = check_cpuid_limit(vcpu, function, index);
656
657 if (best) {
658 kvm_register_write(vcpu, VCPU_REGS_RAX, best->eax);
659 kvm_register_write(vcpu, VCPU_REGS_RBX, best->ebx);
660 kvm_register_write(vcpu, VCPU_REGS_RCX, best->ecx);
661 kvm_register_write(vcpu, VCPU_REGS_RDX, best->edx);
662 }
663 kvm_x86_ops->skip_emulated_instruction(vcpu);
664 trace_kvm_cpuid(function,
665 kvm_register_read(vcpu, VCPU_REGS_RAX),
666 kvm_register_read(vcpu, VCPU_REGS_RBX),
667 kvm_register_read(vcpu, VCPU_REGS_RCX),
668 kvm_register_read(vcpu, VCPU_REGS_RDX));
669}
670EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
generated by cgit v1.2.2 (git 2.25.0) at 2025-03-01 15:15:02 -0500