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Linux 4.1.18
[linux/fpc-iii.git] / arch / x86 / kvm / cpuid.c
blob1d08ad3582d07fd61cd03302eba547e3a997058b
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/i387.h> /* For use_eager_fpu. Ugh! */
20 #include <asm/fpu-internal.h> /* For use_eager_fpu. Ugh! */
21 #include <asm/user.h>
22 #include <asm/xsave.h>
23 #include "cpuid.h"
24 #include "lapic.h"
25 #include "mmu.h"
26 #include "trace.h"
27
28 static u32 xstate_required_size(u64 xstate_bv, bool compacted)
29 {
30 int feature_bit = 0;
31 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
32
33 xstate_bv &= XSTATE_EXTEND_MASK;
34 while (xstate_bv) {
35 if (xstate_bv & 0x1) {
36 u32 eax, ebx, ecx, edx, offset;
37 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
38 offset = compacted ? ret : ebx;
39 ret = max(ret, offset + eax);
40 }
41
42 xstate_bv >>= 1;
43 feature_bit++;
44 }
45
46 return ret;
47 }
48
49 u64 kvm_supported_xcr0(void)
50 {
51 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
52
53 if (!kvm_x86_ops->mpx_supported())
54 xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR);
55
56 return xcr0;
57 }
58
59 #define F(x) bit(X86_FEATURE_##x)
60
61 int kvm_update_cpuid(struct kvm_vcpu *vcpu)
62 {
63 struct kvm_cpuid_entry2 *best;
64 struct kvm_lapic *apic = vcpu->arch.apic;
65
66 best = kvm_find_cpuid_entry(vcpu, 1, 0);
67 if (!best)
68 return 0;
69
70 /* Update OSXSAVE bit */
71 if (cpu_has_xsave && best->function == 0x1) {
72 best->ecx &= ~F(OSXSAVE);
73 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
74 best->ecx |= F(OSXSAVE);
75 }
76
77 if (apic) {
78 if (best->ecx & F(TSC_DEADLINE_TIMER))
79 apic->lapic_timer.timer_mode_mask = 3 << 17;
80 else
81 apic->lapic_timer.timer_mode_mask = 1 << 17;
82 }
83
84 best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
85 if (!best) {
86 vcpu->arch.guest_supported_xcr0 = 0;
87 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
88 } else {
89 vcpu->arch.guest_supported_xcr0 =
90 (best->eax | ((u64)best->edx << 32)) &
91 kvm_supported_xcr0();
92 vcpu->arch.guest_xstate_size = best->ebx =
93 xstate_required_size(vcpu->arch.xcr0, false);
94 }
95
96 best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
97 if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
98 best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
99
100 vcpu->arch.eager_fpu = guest_cpuid_has_mpx(vcpu);
101
102 /*
103 * The existing code assumes virtual address is 48-bit in the canonical
104 * address checks; exit if it is ever changed.
105 */
106 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
107 if (best && ((best->eax & 0xff00) >> 8) != 48 &&
108 ((best->eax & 0xff00) >> 8) != 0)
109 return -EINVAL;
110
111 /* Update physical-address width */
112 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
113
114 kvm_pmu_cpuid_update(vcpu);
115 return 0;
116 }
117
118 static int is_efer_nx(void)
119 {
120 unsigned long long efer = 0;
121
122 rdmsrl_safe(MSR_EFER, &efer);
123 return efer & EFER_NX;
124 }
125
126 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
127 {
128 int i;
129 struct kvm_cpuid_entry2 *e, *entry;
130
131 entry = NULL;
132 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
133 e = &vcpu->arch.cpuid_entries[i];
134 if (e->function == 0x80000001) {
135 entry = e;
136 break;
137 }
138 }
139 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
140 entry->edx &= ~F(NX);
141 printk(KERN_INFO "kvm: guest NX capability removed\n");
142 }
143 }
144
145 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
146 {
147 struct kvm_cpuid_entry2 *best;
148
149 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
150 if (!best || best->eax < 0x80000008)
151 goto not_found;
152 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
153 if (best)
154 return best->eax & 0xff;
155 not_found:
156 return 36;
157 }
158 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
159
160 /* when an old userspace process fills a new kernel module */
161 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
162 struct kvm_cpuid *cpuid,
163 struct kvm_cpuid_entry __user *entries)
164 {
165 int r, i;
166 struct kvm_cpuid_entry *cpuid_entries;
167
168 r = -E2BIG;
169 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
170 goto out;
171 r = -ENOMEM;
172 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent);
173 if (!cpuid_entries)
174 goto out;
175 r = -EFAULT;
176 if (copy_from_user(cpuid_entries, entries,
177 cpuid->nent * sizeof(struct kvm_cpuid_entry)))
178 goto out_free;
179 for (i = 0; i < cpuid->nent; i++) {
180 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
181 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
182 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
183 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
184 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
185 vcpu->arch.cpuid_entries[i].index = 0;
186 vcpu->arch.cpuid_entries[i].flags = 0;
187 vcpu->arch.cpuid_entries[i].padding[0] = 0;
188 vcpu->arch.cpuid_entries[i].padding[1] = 0;
189 vcpu->arch.cpuid_entries[i].padding[2] = 0;
190 }
191 vcpu->arch.cpuid_nent = cpuid->nent;
192 cpuid_fix_nx_cap(vcpu);
193 kvm_apic_set_version(vcpu);
194 kvm_x86_ops->cpuid_update(vcpu);
195 r = kvm_update_cpuid(vcpu);
196
197 out_free:
198 vfree(cpuid_entries);
199 out:
200 return r;
201 }
202
203 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
204 struct kvm_cpuid2 *cpuid,
205 struct kvm_cpuid_entry2 __user *entries)
206 {
207 int r;
208
209 r = -E2BIG;
210 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
211 goto out;
212 r = -EFAULT;
213 if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
214 cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
215 goto out;
216 vcpu->arch.cpuid_nent = cpuid->nent;
217 kvm_apic_set_version(vcpu);
218 kvm_x86_ops->cpuid_update(vcpu);
219 r = kvm_update_cpuid(vcpu);
220 out:
221 return r;
222 }
223
224 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
225 struct kvm_cpuid2 *cpuid,
226 struct kvm_cpuid_entry2 __user *entries)
227 {
228 int r;
229
230 r = -E2BIG;
231 if (cpuid->nent < vcpu->arch.cpuid_nent)
232 goto out;
233 r = -EFAULT;
234 if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
235 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
236 goto out;
237 return 0;
238
239 out:
240 cpuid->nent = vcpu->arch.cpuid_nent;
241 return r;
242 }
243
244 static void cpuid_mask(u32 *word, int wordnum)
245 {
246 *word &= boot_cpu_data.x86_capability[wordnum];
247 }
248
249 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
250 u32 index)
251 {
252 entry->function = function;
253 entry->index = index;
254 cpuid_count(entry->function, entry->index,
255 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
256 entry->flags = 0;
257 }
258
259 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
260 u32 func, u32 index, int *nent, int maxnent)
261 {
262 switch (func) {
263 case 0:
264 entry->eax = 1; /* only one leaf currently */
265 ++*nent;
266 break;
267 case 1:
268 entry->ecx = F(MOVBE);
269 ++*nent;
270 break;
271 default:
272 break;
273 }
274
275 entry->function = func;
276 entry->index = index;
277
278 return 0;
279 }
280
281 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
282 u32 index, int *nent, int maxnent)
283 {
284 int r;
285 unsigned f_nx = is_efer_nx() ? F(NX) : 0;
286 #ifdef CONFIG_X86_64
287 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
288 ? F(GBPAGES) : 0;
289 unsigned f_lm = F(LM);
290 #else
291 unsigned f_gbpages = 0;
292 unsigned f_lm = 0;
293 #endif
294 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
295 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
296 unsigned f_mpx = kvm_x86_ops->mpx_supported() ? F(MPX) : 0;
297 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
298
299 /* cpuid 1.edx */
300 const u32 kvm_supported_word0_x86_features =
301 F(FPU) | F(VME) | F(DE) | F(PSE) |
302 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
303 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
304 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
305 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
306 0 /* Reserved, DS, ACPI */ | F(MMX) |
307 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
308 0 /* HTT, TM, Reserved, PBE */;
309 /* cpuid 0x80000001.edx */
310 const u32 kvm_supported_word1_x86_features =
311 F(FPU) | F(VME) | F(DE) | F(PSE) |
312 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
313 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
314 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
315 F(PAT) | F(PSE36) | 0 /* Reserved */ |
316 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
317 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
318 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
319 /* cpuid 1.ecx */
320 const u32 kvm_supported_word4_x86_features =
321 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
322 * but *not* advertised to guests via CPUID ! */
323 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
324 0 /* DS-CPL, VMX, SMX, EST */ |
325 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
326 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
327 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
328 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
329 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
330 F(F16C) | F(RDRAND);
331 /* cpuid 0x80000001.ecx */
332 const u32 kvm_supported_word6_x86_features =
333 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
334 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
335 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
336 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
337
338 /* cpuid 0xC0000001.edx */
339 const u32 kvm_supported_word5_x86_features =
340 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
341 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
342 F(PMM) | F(PMM_EN);
343
344 /* cpuid 7.0.ebx */
345 const u32 kvm_supported_word9_x86_features =
346 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
347 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
348 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) |
349 F(AVX512CD);
350
351 /* cpuid 0xD.1.eax */
352 const u32 kvm_supported_word10_x86_features =
353 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
354
355 /* all calls to cpuid_count() should be made on the same cpu */
356 get_cpu();
357
358 r = -E2BIG;
359
360 if (*nent >= maxnent)
361 goto out;
362
363 do_cpuid_1_ent(entry, function, index);
364 ++*nent;
365
366 switch (function) {
367 case 0:
368 entry->eax = min(entry->eax, (u32)0xd);
369 break;
370 case 1:
371 entry->edx &= kvm_supported_word0_x86_features;
372 cpuid_mask(&entry->edx, 0);
373 entry->ecx &= kvm_supported_word4_x86_features;
374 cpuid_mask(&entry->ecx, 4);
375 /* we support x2apic emulation even if host does not support
376 * it since we emulate x2apic in software */
377 entry->ecx |= F(X2APIC);
378 break;
379 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
380 * may return different values. This forces us to get_cpu() before
381 * issuing the first command, and also to emulate this annoying behavior
382 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
383 case 2: {
384 int t, times = entry->eax & 0xff;
385
386 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
387 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
388 for (t = 1; t < times; ++t) {
389 if (*nent >= maxnent)
390 goto out;
391
392 do_cpuid_1_ent(&entry[t], function, 0);
393 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
394 ++*nent;
395 }
396 break;
397 }
398 /* function 4 has additional index. */
399 case 4: {
400 int i, cache_type;
401
402 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
403 /* read more entries until cache_type is zero */
404 for (i = 1; ; ++i) {
405 if (*nent >= maxnent)
406 goto out;
407
408 cache_type = entry[i - 1].eax & 0x1f;
409 if (!cache_type)
410 break;
411 do_cpuid_1_ent(&entry[i], function, i);
412 entry[i].flags |=
413 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
414 ++*nent;
415 }
416 break;
417 }
418 case 7: {
419 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
420 /* Mask ebx against host capability word 9 */
421 if (index == 0) {
422 entry->ebx &= kvm_supported_word9_x86_features;
423 cpuid_mask(&entry->ebx, 9);
424 // TSC_ADJUST is emulated
425 entry->ebx |= F(TSC_ADJUST);
426 } else
427 entry->ebx = 0;
428 entry->eax = 0;
429 entry->ecx = 0;
430 entry->edx = 0;
431 break;
432 }
433 case 9:
434 break;
435 case 0xa: { /* Architectural Performance Monitoring */
436 struct x86_pmu_capability cap;
437 union cpuid10_eax eax;
438 union cpuid10_edx edx;
439
440 perf_get_x86_pmu_capability(&cap);
441
442 /*
443 * Only support guest architectural pmu on a host
444 * with architectural pmu.
445 */
446 if (!cap.version)
447 memset(&cap, 0, sizeof(cap));
448
449 eax.split.version_id = min(cap.version, 2);
450 eax.split.num_counters = cap.num_counters_gp;
451 eax.split.bit_width = cap.bit_width_gp;
452 eax.split.mask_length = cap.events_mask_len;
453
454 edx.split.num_counters_fixed = cap.num_counters_fixed;
455 edx.split.bit_width_fixed = cap.bit_width_fixed;
456 edx.split.reserved = 0;
457
458 entry->eax = eax.full;
459 entry->ebx = cap.events_mask;
460 entry->ecx = 0;
461 entry->edx = edx.full;
462 break;
463 }
464 /* function 0xb has additional index. */
465 case 0xb: {
466 int i, level_type;
467
468 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
469 /* read more entries until level_type is zero */
470 for (i = 1; ; ++i) {
471 if (*nent >= maxnent)
472 goto out;
473
474 level_type = entry[i - 1].ecx & 0xff00;
475 if (!level_type)
476 break;
477 do_cpuid_1_ent(&entry[i], function, i);
478 entry[i].flags |=
479 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
480 ++*nent;
481 }
482 break;
483 }
484 case 0xd: {
485 int idx, i;
486 u64 supported = kvm_supported_xcr0();
487
488 entry->eax &= supported;
489 entry->ebx = xstate_required_size(supported, false);
490 entry->ecx = entry->ebx;
491 entry->edx &= supported >> 32;
492 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
493 if (!supported)
494 break;
495
496 for (idx = 1, i = 1; idx < 64; ++idx) {
497 u64 mask = ((u64)1 << idx);
498 if (*nent >= maxnent)
499 goto out;
500
501 do_cpuid_1_ent(&entry[i], function, idx);
502 if (idx == 1) {
503 entry[i].eax &= kvm_supported_word10_x86_features;
504 entry[i].ebx = 0;
505 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
506 entry[i].ebx =
507 xstate_required_size(supported,
508 true);
509 } else {
510 if (entry[i].eax == 0 || !(supported & mask))
511 continue;
512 if (WARN_ON_ONCE(entry[i].ecx & 1))
513 continue;
514 }
515 entry[i].ecx = 0;
516 entry[i].edx = 0;
517 entry[i].flags |=
518 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
519 ++*nent;
520 ++i;
521 }
522 break;
523 }
524 case KVM_CPUID_SIGNATURE: {
525 static const char signature[12] = "KVMKVMKVM\0\0";
526 const u32 *sigptr = (const u32 *)signature;
527 entry->eax = KVM_CPUID_FEATURES;
528 entry->ebx = sigptr[0];
529 entry->ecx = sigptr[1];
530 entry->edx = sigptr[2];
531 break;
532 }
533 case KVM_CPUID_FEATURES:
534 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
535 (1 << KVM_FEATURE_NOP_IO_DELAY) |
536 (1 << KVM_FEATURE_CLOCKSOURCE2) |
537 (1 << KVM_FEATURE_ASYNC_PF) |
538 (1 << KVM_FEATURE_PV_EOI) |
539 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
540 (1 << KVM_FEATURE_PV_UNHALT);
541
542 if (sched_info_on())
543 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
544
545 entry->ebx = 0;
546 entry->ecx = 0;
547 entry->edx = 0;
548 break;
549 case 0x80000000:
550 entry->eax = min(entry->eax, 0x8000001a);
551 break;
552 case 0x80000001:
553 entry->edx &= kvm_supported_word1_x86_features;
554 cpuid_mask(&entry->edx, 1);
555 entry->ecx &= kvm_supported_word6_x86_features;
556 cpuid_mask(&entry->ecx, 6);
557 break;
558 case 0x80000007: /* Advanced power management */
559 /* invariant TSC is CPUID.80000007H:EDX[8] */
560 entry->edx &= (1 << 8);
561 /* mask against host */
562 entry->edx &= boot_cpu_data.x86_power;
563 entry->eax = entry->ebx = entry->ecx = 0;
564 break;
565 case 0x80000008: {
566 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
567 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
568 unsigned phys_as = entry->eax & 0xff;
569
570 if (!g_phys_as)
571 g_phys_as = phys_as;
572 entry->eax = g_phys_as | (virt_as << 8);
573 entry->ebx = entry->edx = 0;
574 break;
575 }
576 case 0x80000019:
577 entry->ecx = entry->edx = 0;
578 break;
579 case 0x8000001a:
580 break;
581 case 0x8000001d:
582 break;
583 /*Add support for Centaur's CPUID instruction*/
584 case 0xC0000000:
585 /*Just support up to 0xC0000004 now*/
586 entry->eax = min(entry->eax, 0xC0000004);
587 break;
588 case 0xC0000001:
589 entry->edx &= kvm_supported_word5_x86_features;
590 cpuid_mask(&entry->edx, 5);
591 break;
592 case 3: /* Processor serial number */
593 case 5: /* MONITOR/MWAIT */
594 case 6: /* Thermal management */
595 case 0xC0000002:
596 case 0xC0000003:
597 case 0xC0000004:
598 default:
599 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
600 break;
601 }
602
603 kvm_x86_ops->set_supported_cpuid(function, entry);
604
605 r = 0;
606
607 out:
608 put_cpu();
609
610 return r;
611 }
612
613 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
614 u32 idx, int *nent, int maxnent, unsigned int type)
615 {
616 if (type == KVM_GET_EMULATED_CPUID)
617 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
618
619 return __do_cpuid_ent(entry, func, idx, nent, maxnent);
620 }
621
622 #undef F
623
624 struct kvm_cpuid_param {
625 u32 func;
626 u32 idx;
627 bool has_leaf_count;
628 bool (*qualifier)(const struct kvm_cpuid_param *param);
629 };
630
631 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
632 {
633 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
634 }
635
636 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
637 __u32 num_entries, unsigned int ioctl_type)
638 {
639 int i;
640 __u32 pad[3];
641
642 if (ioctl_type != KVM_GET_EMULATED_CPUID)
643 return false;
644
645 /*
646 * We want to make sure that ->padding is being passed clean from
647 * userspace in case we want to use it for something in the future.
648 *
649 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
650 * have to give ourselves satisfied only with the emulated side. /me
651 * sheds a tear.
652 */
653 for (i = 0; i < num_entries; i++) {
654 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
655 return true;
656
657 if (pad[0] || pad[1] || pad[2])
658 return true;
659 }
660 return false;
661 }
662
663 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
664 struct kvm_cpuid_entry2 __user *entries,
665 unsigned int type)
666 {
667 struct kvm_cpuid_entry2 *cpuid_entries;
668 int limit, nent = 0, r = -E2BIG, i;
669 u32 func;
670 static const struct kvm_cpuid_param param[] = {
671 { .func = 0, .has_leaf_count = true },
672 { .func = 0x80000000, .has_leaf_count = true },
673 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
674 { .func = KVM_CPUID_SIGNATURE },
675 { .func = KVM_CPUID_FEATURES },
676 };
677
678 if (cpuid->nent < 1)
679 goto out;
680 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
681 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
682
683 if (sanity_check_entries(entries, cpuid->nent, type))
684 return -EINVAL;
685
686 r = -ENOMEM;
687 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
688 if (!cpuid_entries)
689 goto out;
690
691 r = 0;
692 for (i = 0; i < ARRAY_SIZE(param); i++) {
693 const struct kvm_cpuid_param *ent = &param[i];
694
695 if (ent->qualifier && !ent->qualifier(ent))
696 continue;
697
698 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
699 &nent, cpuid->nent, type);
700
701 if (r)
702 goto out_free;
703
704 if (!ent->has_leaf_count)
705 continue;
706
707 limit = cpuid_entries[nent - 1].eax;
708 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
709 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
710 &nent, cpuid->nent, type);
711
712 if (r)
713 goto out_free;
714 }
715
716 r = -EFAULT;
717 if (copy_to_user(entries, cpuid_entries,
718 nent * sizeof(struct kvm_cpuid_entry2)))
719 goto out_free;
720 cpuid->nent = nent;
721 r = 0;
722
723 out_free:
724 vfree(cpuid_entries);
725 out:
726 return r;
727 }
728
729 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
730 {
731 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
732 int j, nent = vcpu->arch.cpuid_nent;
733
734 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
735 /* when no next entry is found, the current entry[i] is reselected */
736 for (j = i + 1; ; j = (j + 1) % nent) {
737 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
738 if (ej->function == e->function) {
739 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
740 return j;
741 }
742 }
743 return 0; /* silence gcc, even though control never reaches here */
744 }
745
746 /* find an entry with matching function, matching index (if needed), and that
747 * should be read next (if it's stateful) */
748 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
749 u32 function, u32 index)
750 {
751 if (e->function != function)
752 return 0;
753 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
754 return 0;
755 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
756 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
757 return 0;
758 return 1;
759 }
760
761 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
762 u32 function, u32 index)
763 {
764 int i;
765 struct kvm_cpuid_entry2 *best = NULL;
766
767 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
768 struct kvm_cpuid_entry2 *e;
769
770 e = &vcpu->arch.cpuid_entries[i];
771 if (is_matching_cpuid_entry(e, function, index)) {
772 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
773 move_to_next_stateful_cpuid_entry(vcpu, i);
774 best = e;
775 break;
776 }
777 }
778 return best;
779 }
780 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
781
782 /*
783 * If no match is found, check whether we exceed the vCPU's limit
784 * and return the content of the highest valid _standard_ leaf instead.
785 * This is to satisfy the CPUID specification.
786 */
787 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
788 u32 function, u32 index)
789 {
790 struct kvm_cpuid_entry2 *maxlevel;
791
792 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
793 if (!maxlevel || maxlevel->eax >= function)
794 return NULL;
795 if (function & 0x80000000) {
796 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
797 if (!maxlevel)
798 return NULL;
799 }
800 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
801 }
802
803 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
804 {
805 u32 function = *eax, index = *ecx;
806 struct kvm_cpuid_entry2 *best;
807
808 best = kvm_find_cpuid_entry(vcpu, function, index);
809
810 if (!best)
811 best = check_cpuid_limit(vcpu, function, index);
812
813 /*
814 * Perfmon not yet supported for L2 guest.
815 */
816 if (is_guest_mode(vcpu) && function == 0xa)
817 best = NULL;
818
819 if (best) {
820 *eax = best->eax;
821 *ebx = best->ebx;
822 *ecx = best->ecx;
823 *edx = best->edx;
824 } else
825 *eax = *ebx = *ecx = *edx = 0;
826 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx);
827 }
828 EXPORT_SYMBOL_GPL(kvm_cpuid);
829
830 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
831 {
832 u32 function, eax, ebx, ecx, edx;
833
834 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
835 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
836 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx);
837 kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
838 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
839 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
840 kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
841 kvm_x86_ops->skip_emulated_instruction(vcpu);
842 }
843 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
Linux with added FPC-III support