Loading...
Note: File does not exist in v3.1.
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
30static 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
51bool kvm_mpx_supported(void)
52{
53 return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR))
54 && kvm_x86_ops->mpx_supported());
55}
56EXPORT_SYMBOL_GPL(kvm_mpx_supported);
57
58u64 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
73int 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 best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0);
139 if (kvm_hlt_in_guest(vcpu->kvm) && best &&
140 (best->eax & (1 << KVM_FEATURE_PV_UNHALT)))
141 best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT);
142
143 /* Update physical-address width */
144 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
145 kvm_mmu_reset_context(vcpu);
146
147 kvm_pmu_refresh(vcpu);
148 return 0;
149}
150
151static int is_efer_nx(void)
152{
153 unsigned long long efer = 0;
154
155 rdmsrl_safe(MSR_EFER, &efer);
156 return efer & EFER_NX;
157}
158
159static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
160{
161 int i;
162 struct kvm_cpuid_entry2 *e, *entry;
163
164 entry = NULL;
165 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
166 e = &vcpu->arch.cpuid_entries[i];
167 if (e->function == 0x80000001) {
168 entry = e;
169 break;
170 }
171 }
172 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
173 entry->edx &= ~F(NX);
174 printk(KERN_INFO "kvm: guest NX capability removed\n");
175 }
176}
177
178int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
179{
180 struct kvm_cpuid_entry2 *best;
181
182 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
183 if (!best || best->eax < 0x80000008)
184 goto not_found;
185 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
186 if (best)
187 return best->eax & 0xff;
188not_found:
189 return 36;
190}
191EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
192
193/* when an old userspace process fills a new kernel module */
194int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
195 struct kvm_cpuid *cpuid,
196 struct kvm_cpuid_entry __user *entries)
197{
198 int r, i;
199 struct kvm_cpuid_entry *cpuid_entries = NULL;
200
201 r = -E2BIG;
202 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
203 goto out;
204 r = -ENOMEM;
205 if (cpuid->nent) {
206 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) *
207 cpuid->nent);
208 if (!cpuid_entries)
209 goto out;
210 r = -EFAULT;
211 if (copy_from_user(cpuid_entries, entries,
212 cpuid->nent * sizeof(struct kvm_cpuid_entry)))
213 goto out;
214 }
215 for (i = 0; i < cpuid->nent; i++) {
216 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
217 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
218 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
219 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
220 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
221 vcpu->arch.cpuid_entries[i].index = 0;
222 vcpu->arch.cpuid_entries[i].flags = 0;
223 vcpu->arch.cpuid_entries[i].padding[0] = 0;
224 vcpu->arch.cpuid_entries[i].padding[1] = 0;
225 vcpu->arch.cpuid_entries[i].padding[2] = 0;
226 }
227 vcpu->arch.cpuid_nent = cpuid->nent;
228 cpuid_fix_nx_cap(vcpu);
229 kvm_apic_set_version(vcpu);
230 kvm_x86_ops->cpuid_update(vcpu);
231 r = kvm_update_cpuid(vcpu);
232
233out:
234 vfree(cpuid_entries);
235 return r;
236}
237
238int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
239 struct kvm_cpuid2 *cpuid,
240 struct kvm_cpuid_entry2 __user *entries)
241{
242 int r;
243
244 r = -E2BIG;
245 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
246 goto out;
247 r = -EFAULT;
248 if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
249 cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
250 goto out;
251 vcpu->arch.cpuid_nent = cpuid->nent;
252 kvm_apic_set_version(vcpu);
253 kvm_x86_ops->cpuid_update(vcpu);
254 r = kvm_update_cpuid(vcpu);
255out:
256 return r;
257}
258
259int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
260 struct kvm_cpuid2 *cpuid,
261 struct kvm_cpuid_entry2 __user *entries)
262{
263 int r;
264
265 r = -E2BIG;
266 if (cpuid->nent < vcpu->arch.cpuid_nent)
267 goto out;
268 r = -EFAULT;
269 if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
270 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
271 goto out;
272 return 0;
273
274out:
275 cpuid->nent = vcpu->arch.cpuid_nent;
276 return r;
277}
278
279static void cpuid_mask(u32 *word, int wordnum)
280{
281 *word &= boot_cpu_data.x86_capability[wordnum];
282}
283
284static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
285 u32 index)
286{
287 entry->function = function;
288 entry->index = index;
289 cpuid_count(entry->function, entry->index,
290 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
291 entry->flags = 0;
292}
293
294static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
295 u32 func, u32 index, int *nent, int maxnent)
296{
297 switch (func) {
298 case 0:
299 entry->eax = 7;
300 ++*nent;
301 break;
302 case 1:
303 entry->ecx = F(MOVBE);
304 ++*nent;
305 break;
306 case 7:
307 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
308 if (index == 0)
309 entry->ecx = F(RDPID);
310 ++*nent;
311 default:
312 break;
313 }
314
315 entry->function = func;
316 entry->index = index;
317
318 return 0;
319}
320
321static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
322 u32 index, int *nent, int maxnent)
323{
324 int r;
325 unsigned f_nx = is_efer_nx() ? F(NX) : 0;
326#ifdef CONFIG_X86_64
327 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
328 ? F(GBPAGES) : 0;
329 unsigned f_lm = F(LM);
330#else
331 unsigned f_gbpages = 0;
332 unsigned f_lm = 0;
333#endif
334 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
335 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
336 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
337 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
338 unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0;
339
340 /* cpuid 1.edx */
341 const u32 kvm_cpuid_1_edx_x86_features =
342 F(FPU) | F(VME) | F(DE) | F(PSE) |
343 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
344 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
345 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
346 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
347 0 /* Reserved, DS, ACPI */ | F(MMX) |
348 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
349 0 /* HTT, TM, Reserved, PBE */;
350 /* cpuid 0x80000001.edx */
351 const u32 kvm_cpuid_8000_0001_edx_x86_features =
352 F(FPU) | F(VME) | F(DE) | F(PSE) |
353 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
354 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
355 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
356 F(PAT) | F(PSE36) | 0 /* Reserved */ |
357 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
358 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
359 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
360 /* cpuid 1.ecx */
361 const u32 kvm_cpuid_1_ecx_x86_features =
362 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
363 * but *not* advertised to guests via CPUID ! */
364 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
365 0 /* DS-CPL, VMX, SMX, EST */ |
366 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
367 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
368 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
369 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
370 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
371 F(F16C) | F(RDRAND);
372 /* cpuid 0x80000001.ecx */
373 const u32 kvm_cpuid_8000_0001_ecx_x86_features =
374 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
375 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
376 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
377 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) |
378 F(TOPOEXT) | F(PERFCTR_CORE);
379
380 /* cpuid 0x80000008.ebx */
381 const u32 kvm_cpuid_8000_0008_ebx_x86_features =
382 F(AMD_IBPB) | F(AMD_IBRS) | F(VIRT_SSBD);
383
384 /* cpuid 0xC0000001.edx */
385 const u32 kvm_cpuid_C000_0001_edx_x86_features =
386 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
387 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
388 F(PMM) | F(PMM_EN);
389
390 /* cpuid 7.0.ebx */
391 const u32 kvm_cpuid_7_0_ebx_x86_features =
392 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
393 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
394 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
395 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) |
396 F(SHA_NI) | F(AVX512BW) | F(AVX512VL);
397
398 /* cpuid 0xD.1.eax */
399 const u32 kvm_cpuid_D_1_eax_x86_features =
400 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
401
402 /* cpuid 7.0.ecx*/
403 const u32 kvm_cpuid_7_0_ecx_x86_features =
404 F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ |
405 F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) |
406 F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG);
407
408 /* cpuid 7.0.edx*/
409 const u32 kvm_cpuid_7_0_edx_x86_features =
410 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
411 F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES);
412
413 /* all calls to cpuid_count() should be made on the same cpu */
414 get_cpu();
415
416 r = -E2BIG;
417
418 if (*nent >= maxnent)
419 goto out;
420
421 do_cpuid_1_ent(entry, function, index);
422 ++*nent;
423
424 switch (function) {
425 case 0:
426 entry->eax = min(entry->eax, (u32)0xd);
427 break;
428 case 1:
429 entry->edx &= kvm_cpuid_1_edx_x86_features;
430 cpuid_mask(&entry->edx, CPUID_1_EDX);
431 entry->ecx &= kvm_cpuid_1_ecx_x86_features;
432 cpuid_mask(&entry->ecx, CPUID_1_ECX);
433 /* we support x2apic emulation even if host does not support
434 * it since we emulate x2apic in software */
435 entry->ecx |= F(X2APIC);
436 break;
437 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
438 * may return different values. This forces us to get_cpu() before
439 * issuing the first command, and also to emulate this annoying behavior
440 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
441 case 2: {
442 int t, times = entry->eax & 0xff;
443
444 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
445 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
446 for (t = 1; t < times; ++t) {
447 if (*nent >= maxnent)
448 goto out;
449
450 do_cpuid_1_ent(&entry[t], function, 0);
451 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
452 ++*nent;
453 }
454 break;
455 }
456 /* function 4 has additional index. */
457 case 4: {
458 int i, cache_type;
459
460 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
461 /* read more entries until cache_type is zero */
462 for (i = 1; ; ++i) {
463 if (*nent >= maxnent)
464 goto out;
465
466 cache_type = entry[i - 1].eax & 0x1f;
467 if (!cache_type)
468 break;
469 do_cpuid_1_ent(&entry[i], function, i);
470 entry[i].flags |=
471 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
472 ++*nent;
473 }
474 break;
475 }
476 case 6: /* Thermal management */
477 entry->eax = 0x4; /* allow ARAT */
478 entry->ebx = 0;
479 entry->ecx = 0;
480 entry->edx = 0;
481 break;
482 case 7: {
483 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
484 /* Mask ebx against host capability word 9 */
485 if (index == 0) {
486 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features;
487 cpuid_mask(&entry->ebx, CPUID_7_0_EBX);
488 // TSC_ADJUST is emulated
489 entry->ebx |= F(TSC_ADJUST);
490 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
491 cpuid_mask(&entry->ecx, CPUID_7_ECX);
492 entry->ecx |= f_umip;
493 /* PKU is not yet implemented for shadow paging. */
494 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
495 entry->ecx &= ~F(PKU);
496 entry->edx &= kvm_cpuid_7_0_edx_x86_features;
497 cpuid_mask(&entry->edx, CPUID_7_EDX);
498 /*
499 * We emulate ARCH_CAPABILITIES in software even
500 * if the host doesn't support it.
501 */
502 entry->edx |= F(ARCH_CAPABILITIES);
503 } else {
504 entry->ebx = 0;
505 entry->ecx = 0;
506 entry->edx = 0;
507 }
508 entry->eax = 0;
509 break;
510 }
511 case 9:
512 break;
513 case 0xa: { /* Architectural Performance Monitoring */
514 struct x86_pmu_capability cap;
515 union cpuid10_eax eax;
516 union cpuid10_edx edx;
517
518 perf_get_x86_pmu_capability(&cap);
519
520 /*
521 * Only support guest architectural pmu on a host
522 * with architectural pmu.
523 */
524 if (!cap.version)
525 memset(&cap, 0, sizeof(cap));
526
527 eax.split.version_id = min(cap.version, 2);
528 eax.split.num_counters = cap.num_counters_gp;
529 eax.split.bit_width = cap.bit_width_gp;
530 eax.split.mask_length = cap.events_mask_len;
531
532 edx.split.num_counters_fixed = cap.num_counters_fixed;
533 edx.split.bit_width_fixed = cap.bit_width_fixed;
534 edx.split.reserved = 0;
535
536 entry->eax = eax.full;
537 entry->ebx = cap.events_mask;
538 entry->ecx = 0;
539 entry->edx = edx.full;
540 break;
541 }
542 /* function 0xb has additional index. */
543 case 0xb: {
544 int i, level_type;
545
546 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
547 /* read more entries until level_type is zero */
548 for (i = 1; ; ++i) {
549 if (*nent >= maxnent)
550 goto out;
551
552 level_type = entry[i - 1].ecx & 0xff00;
553 if (!level_type)
554 break;
555 do_cpuid_1_ent(&entry[i], function, i);
556 entry[i].flags |=
557 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
558 ++*nent;
559 }
560 break;
561 }
562 case 0xd: {
563 int idx, i;
564 u64 supported = kvm_supported_xcr0();
565
566 entry->eax &= supported;
567 entry->ebx = xstate_required_size(supported, false);
568 entry->ecx = entry->ebx;
569 entry->edx &= supported >> 32;
570 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
571 if (!supported)
572 break;
573
574 for (idx = 1, i = 1; idx < 64; ++idx) {
575 u64 mask = ((u64)1 << idx);
576 if (*nent >= maxnent)
577 goto out;
578
579 do_cpuid_1_ent(&entry[i], function, idx);
580 if (idx == 1) {
581 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
582 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
583 entry[i].ebx = 0;
584 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
585 entry[i].ebx =
586 xstate_required_size(supported,
587 true);
588 } else {
589 if (entry[i].eax == 0 || !(supported & mask))
590 continue;
591 if (WARN_ON_ONCE(entry[i].ecx & 1))
592 continue;
593 }
594 entry[i].ecx = 0;
595 entry[i].edx = 0;
596 entry[i].flags |=
597 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
598 ++*nent;
599 ++i;
600 }
601 break;
602 }
603 case KVM_CPUID_SIGNATURE: {
604 static const char signature[12] = "KVMKVMKVM\0\0";
605 const u32 *sigptr = (const u32 *)signature;
606 entry->eax = KVM_CPUID_FEATURES;
607 entry->ebx = sigptr[0];
608 entry->ecx = sigptr[1];
609 entry->edx = sigptr[2];
610 break;
611 }
612 case KVM_CPUID_FEATURES:
613 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
614 (1 << KVM_FEATURE_NOP_IO_DELAY) |
615 (1 << KVM_FEATURE_CLOCKSOURCE2) |
616 (1 << KVM_FEATURE_ASYNC_PF) |
617 (1 << KVM_FEATURE_PV_EOI) |
618 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
619 (1 << KVM_FEATURE_PV_UNHALT) |
620 (1 << KVM_FEATURE_PV_TLB_FLUSH) |
621 (1 << KVM_FEATURE_ASYNC_PF_VMEXIT);
622
623 if (sched_info_on())
624 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
625
626 entry->ebx = 0;
627 entry->ecx = 0;
628 entry->edx = 0;
629 break;
630 case 0x80000000:
631 entry->eax = min(entry->eax, 0x8000001f);
632 break;
633 case 0x80000001:
634 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features;
635 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX);
636 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features;
637 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX);
638 break;
639 case 0x80000007: /* Advanced power management */
640 /* invariant TSC is CPUID.80000007H:EDX[8] */
641 entry->edx &= (1 << 8);
642 /* mask against host */
643 entry->edx &= boot_cpu_data.x86_power;
644 entry->eax = entry->ebx = entry->ecx = 0;
645 break;
646 case 0x80000008: {
647 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
648 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
649 unsigned phys_as = entry->eax & 0xff;
650
651 if (!g_phys_as)
652 g_phys_as = phys_as;
653 entry->eax = g_phys_as | (virt_as << 8);
654 entry->edx = 0;
655 /*
656 * IBRS, IBPB and VIRT_SSBD aren't necessarily present in
657 * hardware cpuid
658 */
659 if (boot_cpu_has(X86_FEATURE_AMD_IBPB))
660 entry->ebx |= F(AMD_IBPB);
661 if (boot_cpu_has(X86_FEATURE_AMD_IBRS))
662 entry->ebx |= F(AMD_IBRS);
663 if (boot_cpu_has(X86_FEATURE_VIRT_SSBD))
664 entry->ebx |= F(VIRT_SSBD);
665 entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
666 cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
667 if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD))
668 entry->ebx |= F(VIRT_SSBD);
669 break;
670 }
671 case 0x80000019:
672 entry->ecx = entry->edx = 0;
673 break;
674 case 0x8000001a:
675 break;
676 case 0x8000001d:
677 break;
678 /*Add support for Centaur's CPUID instruction*/
679 case 0xC0000000:
680 /*Just support up to 0xC0000004 now*/
681 entry->eax = min(entry->eax, 0xC0000004);
682 break;
683 case 0xC0000001:
684 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features;
685 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX);
686 break;
687 case 3: /* Processor serial number */
688 case 5: /* MONITOR/MWAIT */
689 case 0xC0000002:
690 case 0xC0000003:
691 case 0xC0000004:
692 default:
693 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
694 break;
695 }
696
697 kvm_x86_ops->set_supported_cpuid(function, entry);
698
699 r = 0;
700
701out:
702 put_cpu();
703
704 return r;
705}
706
707static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
708 u32 idx, int *nent, int maxnent, unsigned int type)
709{
710 if (type == KVM_GET_EMULATED_CPUID)
711 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
712
713 return __do_cpuid_ent(entry, func, idx, nent, maxnent);
714}
715
716#undef F
717
718struct kvm_cpuid_param {
719 u32 func;
720 u32 idx;
721 bool has_leaf_count;
722 bool (*qualifier)(const struct kvm_cpuid_param *param);
723};
724
725static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
726{
727 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
728}
729
730static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
731 __u32 num_entries, unsigned int ioctl_type)
732{
733 int i;
734 __u32 pad[3];
735
736 if (ioctl_type != KVM_GET_EMULATED_CPUID)
737 return false;
738
739 /*
740 * We want to make sure that ->padding is being passed clean from
741 * userspace in case we want to use it for something in the future.
742 *
743 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
744 * have to give ourselves satisfied only with the emulated side. /me
745 * sheds a tear.
746 */
747 for (i = 0; i < num_entries; i++) {
748 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
749 return true;
750
751 if (pad[0] || pad[1] || pad[2])
752 return true;
753 }
754 return false;
755}
756
757int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
758 struct kvm_cpuid_entry2 __user *entries,
759 unsigned int type)
760{
761 struct kvm_cpuid_entry2 *cpuid_entries;
762 int limit, nent = 0, r = -E2BIG, i;
763 u32 func;
764 static const struct kvm_cpuid_param param[] = {
765 { .func = 0, .has_leaf_count = true },
766 { .func = 0x80000000, .has_leaf_count = true },
767 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
768 { .func = KVM_CPUID_SIGNATURE },
769 { .func = KVM_CPUID_FEATURES },
770 };
771
772 if (cpuid->nent < 1)
773 goto out;
774 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
775 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
776
777 if (sanity_check_entries(entries, cpuid->nent, type))
778 return -EINVAL;
779
780 r = -ENOMEM;
781 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
782 if (!cpuid_entries)
783 goto out;
784
785 r = 0;
786 for (i = 0; i < ARRAY_SIZE(param); i++) {
787 const struct kvm_cpuid_param *ent = ¶m[i];
788
789 if (ent->qualifier && !ent->qualifier(ent))
790 continue;
791
792 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
793 &nent, cpuid->nent, type);
794
795 if (r)
796 goto out_free;
797
798 if (!ent->has_leaf_count)
799 continue;
800
801 limit = cpuid_entries[nent - 1].eax;
802 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
803 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
804 &nent, cpuid->nent, type);
805
806 if (r)
807 goto out_free;
808 }
809
810 r = -EFAULT;
811 if (copy_to_user(entries, cpuid_entries,
812 nent * sizeof(struct kvm_cpuid_entry2)))
813 goto out_free;
814 cpuid->nent = nent;
815 r = 0;
816
817out_free:
818 vfree(cpuid_entries);
819out:
820 return r;
821}
822
823static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
824{
825 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
826 struct kvm_cpuid_entry2 *ej;
827 int j = i;
828 int nent = vcpu->arch.cpuid_nent;
829
830 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
831 /* when no next entry is found, the current entry[i] is reselected */
832 do {
833 j = (j + 1) % nent;
834 ej = &vcpu->arch.cpuid_entries[j];
835 } while (ej->function != e->function);
836
837 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
838
839 return j;
840}
841
842/* find an entry with matching function, matching index (if needed), and that
843 * should be read next (if it's stateful) */
844static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
845 u32 function, u32 index)
846{
847 if (e->function != function)
848 return 0;
849 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
850 return 0;
851 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
852 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
853 return 0;
854 return 1;
855}
856
857struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
858 u32 function, u32 index)
859{
860 int i;
861 struct kvm_cpuid_entry2 *best = NULL;
862
863 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
864 struct kvm_cpuid_entry2 *e;
865
866 e = &vcpu->arch.cpuid_entries[i];
867 if (is_matching_cpuid_entry(e, function, index)) {
868 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
869 move_to_next_stateful_cpuid_entry(vcpu, i);
870 best = e;
871 break;
872 }
873 }
874 return best;
875}
876EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
877
878/*
879 * If no match is found, check whether we exceed the vCPU's limit
880 * and return the content of the highest valid _standard_ leaf instead.
881 * This is to satisfy the CPUID specification.
882 */
883static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
884 u32 function, u32 index)
885{
886 struct kvm_cpuid_entry2 *maxlevel;
887
888 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
889 if (!maxlevel || maxlevel->eax >= function)
890 return NULL;
891 if (function & 0x80000000) {
892 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
893 if (!maxlevel)
894 return NULL;
895 }
896 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
897}
898
899bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
900 u32 *ecx, u32 *edx, bool check_limit)
901{
902 u32 function = *eax, index = *ecx;
903 struct kvm_cpuid_entry2 *best;
904 bool entry_found = true;
905
906 best = kvm_find_cpuid_entry(vcpu, function, index);
907
908 if (!best) {
909 entry_found = false;
910 if (!check_limit)
911 goto out;
912
913 best = check_cpuid_limit(vcpu, function, index);
914 }
915
916out:
917 if (best) {
918 *eax = best->eax;
919 *ebx = best->ebx;
920 *ecx = best->ecx;
921 *edx = best->edx;
922 } else
923 *eax = *ebx = *ecx = *edx = 0;
924 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found);
925 return entry_found;
926}
927EXPORT_SYMBOL_GPL(kvm_cpuid);
928
929int kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
930{
931 u32 eax, ebx, ecx, edx;
932
933 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0))
934 return 1;
935
936 eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
937 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
938 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true);
939 kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
940 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
941 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
942 kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
943 return kvm_skip_emulated_instruction(vcpu);
944}
945EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);