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