aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kvm/cpuid.c
blob: 5720e78b2f7b52fa9a05bc52064d4fb8cac04c6c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
/*
 * Kernel-based Virtual Machine driver for Linux
 * cpuid support routines
 *
 * derived from arch/x86/kvm/x86.c
 *
 * Copyright 2011 Red Hat, Inc. and/or its affiliates.
 * Copyright IBM Corporation, 2008
 *
 * This work is licensed under the terms of the GNU GPL, version 2.  See
 * the COPYING file in the top-level directory.
 *
 */

#include <linux/kvm_host.h>
#include <linux/export.h>
#include <linux/vmalloc.h>
#include <linux/uaccess.h>
#include <linux/sched/stat.h>

#include <asm/processor.h>
#include <asm/user.h>
#include <asm/fpu/xstate.h>
#include "cpuid.h"
#include "lapic.h"
#include "mmu.h"
#include "trace.h"
#include "pmu.h"

static u32 xstate_required_size(u64 xstate_bv, bool compacted)
{
	int feature_bit = 0;
	u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;

	xstate_bv &= XFEATURE_MASK_EXTEND;
	while (xstate_bv) {
		if (xstate_bv & 0x1) {
		        u32 eax, ebx, ecx, edx, offset;
		        cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
			offset = compacted ? ret : ebx;
			ret = max(ret, offset + eax);
		}

		xstate_bv >>= 1;
		feature_bit++;
	}

	return ret;
}

bool kvm_mpx_supported(void)
{
	return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR))
		 && kvm_x86_ops->mpx_supported());
}
EXPORT_SYMBOL_GPL(kvm_mpx_supported);

u64 kvm_supported_xcr0(void)
{
	u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;

	if (!kvm_mpx_supported())
		xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);

	return xcr0;
}

#define F(x) bit(X86_FEATURE_##x)

/* For scattered features from cpufeatures.h; we currently expose none */
#define KF(x) bit(KVM_CPUID_BIT_##x)

int kvm_update_cpuid(struct kvm_vcpu *vcpu)
{
	struct kvm_cpuid_entry2 *best;
	struct kvm_lapic *apic = vcpu->arch.apic;

	best = kvm_find_cpuid_entry(vcpu, 1, 0);
	if (!best)
		return 0;

	/* Update OSXSAVE bit */
	if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) {
		best->ecx &= ~F(OSXSAVE);
		if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
			best->ecx |= F(OSXSAVE);
	}

	best->edx &= ~F(APIC);
	if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE)
		best->edx |= F(APIC);

	if (apic) {
		if (best->ecx & F(TSC_DEADLINE_TIMER))
			apic->lapic_timer.timer_mode_mask = 3 << 17;
		else
			apic->lapic_timer.timer_mode_mask = 1 << 17;
	}

	best = kvm_find_cpuid_entry(vcpu, 7, 0);
	if (best) {
		/* Update OSPKE bit */
		if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) {
			best->ecx &= ~F(OSPKE);
			if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE))
				best->ecx |= F(OSPKE);
		}
	}

	best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
	if (!best) {
		vcpu->arch.guest_supported_xcr0 = 0;
		vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
	} else {
		vcpu->arch.guest_supported_xcr0 =
			(best->eax | ((u64)best->edx << 32)) &
			kvm_supported_xcr0();
		vcpu->arch.guest_xstate_size = best->ebx =
			xstate_required_size(vcpu->arch.xcr0, false);
	}

	best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
	if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
		best->ebx = xstate_required_size(vcpu->arch.xcr0, true);

	/*
	 * The existing code assumes virtual address is 48-bit or 57-bit in the
	 * canonical address checks; exit if it is ever changed.
	 */
	best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
	if (best) {
		int vaddr_bits = (best->eax & 0xff00) >> 8;

		if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
			return -EINVAL;
	}

	best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0);
	if (kvm_hlt_in_guest(vcpu->kvm) && best &&
		(best->eax & (1 << KVM_FEATURE_PV_UNHALT)))
		best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT);

	/* Update physical-address width */
	vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
	kvm_mmu_reset_context(vcpu);

	kvm_pmu_refresh(vcpu);
	return 0;
}

static int is_efer_nx(void)
{
	unsigned long long efer = 0;

	rdmsrl_safe(MSR_EFER, &efer);
	return efer & EFER_NX;
}

static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
{
	int i;
	struct kvm_cpuid_entry2 *e, *entry;

	entry = NULL;
	for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
		e = &vcpu->arch.cpuid_entries[i];
		if (e->function == 0x80000001) {
			entry = e;
			break;
		}
	}
	if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
		entry->edx &= ~F(NX);
		printk(KERN_INFO "kvm: guest NX capability removed\n");
	}
}

int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
{
	struct kvm_cpuid_entry2 *best;

	best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
	if (!best || best->eax < 0x80000008)
		goto not_found;
	best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
	if (best)
		return best->eax & 0xff;
not_found:
	return 36;
}
EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);

/* when an old userspace process fills a new kernel module */
int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
			     struct kvm_cpuid *cpuid,
			     struct kvm_cpuid_entry __user *entries)
{
	int r, i;
	struct kvm_cpuid_entry *cpuid_entries = NULL;

	r = -E2BIG;
	if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
		goto out;
	r = -ENOMEM;
	if (cpuid->nent) {
		cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) *
					cpuid->nent);
		if (!cpuid_entries)
			goto out;
		r = -EFAULT;
		if (copy_from_user(cpuid_entries, entries,
				   cpuid->nent * sizeof(struct kvm_cpuid_entry)))
			goto out;
	}
	for (i = 0; i < cpuid->nent; i++) {
		vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
		vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
		vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
		vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
		vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
		vcpu->arch.cpuid_entries[i].index = 0;
		vcpu->arch.cpuid_entries[i].flags = 0;
		vcpu->arch.cpuid_entries[i].padding[0] = 0;
		vcpu->arch.cpuid_entries[i].padding[1] = 0;
		vcpu->arch.cpuid_entries[i].padding[2] = 0;
	}
	vcpu->arch.cpuid_nent = cpuid->nent;
	cpuid_fix_nx_cap(vcpu);
	kvm_apic_set_version(vcpu);
	kvm_x86_ops->cpuid_update(vcpu);
	r = kvm_update_cpuid(vcpu);

out:
	vfree(cpuid_entries);
	return r;
}

int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
			      struct kvm_cpuid2 *cpuid,
			      struct kvm_cpuid_entry2 __user *entries)
{
	int r;

	r = -E2BIG;
	if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
		goto out;
	r = -EFAULT;
	if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
			   cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
		goto out;
	vcpu->arch.cpuid_nent = cpuid->nent;
	kvm_apic_set_version(vcpu);
	kvm_x86_ops->cpuid_update(vcpu);
	r = kvm_update_cpuid(vcpu);
out:
	return r;
}

int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
			      struct kvm_cpuid2 *cpuid,
			      struct kvm_cpuid_entry2 __user *entries)
{
	int r;

	r = -E2BIG;
	if (cpuid->nent < vcpu->arch.cpuid_nent)
		goto out;
	r = -EFAULT;
	if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
			 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
		goto out;
	return 0;

out:
	cpuid->nent = vcpu->arch.cpuid_nent;
	return r;
}

static void cpuid_mask(u32 *word, int wordnum)
{
	*word &= boot_cpu_data.x86_capability[wordnum];
}

static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
			   u32 index)
{
	entry->function = function;
	entry->index = index;
	cpuid_count(entry->function, entry->index,
		    &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
	entry->flags = 0;
}

static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
				   u32 func, u32 index, int *nent, int maxnent)
{
	switch (func) {
	case 0:
		entry->eax = 7;
		++*nent;
		break;
	case 1:
		entry->ecx = F(MOVBE);
		++*nent;
		break;
	case 7:
		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
		if (index == 0)
			entry->ecx = F(RDPID);
		++*nent;
	default:
		break;
	}

	entry->function = func;
	entry->index = index;

	return 0;
}

static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
				 u32 index, int *nent, int maxnent)
{
	int r;
	unsigned f_nx = is_efer_nx() ? F(NX) : 0;
#ifdef CONFIG_X86_64
	unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
				? F(GBPAGES) : 0;
	unsigned f_lm = F(LM);
#else
	unsigned f_gbpages = 0;
	unsigned f_lm = 0;
#endif
	unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
	unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
	unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
	unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
	unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0;

	/* cpuid 1.edx */
	const u32 kvm_cpuid_1_edx_x86_features =
		F(FPU) | F(VME) | F(DE) | F(PSE) |
		F(TSC) | F(MSR) | F(PAE) | F(MCE) |
		F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
		F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
		F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
		0 /* Reserved, DS, ACPI */ | F(MMX) |
		F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
		0 /* HTT, TM, Reserved, PBE */;
	/* cpuid 0x80000001.edx */
	const u32 kvm_cpuid_8000_0001_edx_x86_features =
		F(FPU) | F(VME) | F(DE) | F(PSE) |
		F(TSC) | F(MSR) | F(PAE) | F(MCE) |
		F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
		F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
		F(PAT) | F(PSE36) | 0 /* Reserved */ |
		f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
		F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
		0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
	/* cpuid 1.ecx */
	const u32 kvm_cpuid_1_ecx_x86_features =
		/* NOTE: MONITOR (and MWAIT) are emulated as NOP,
		 * but *not* advertised to guests via CPUID ! */
		F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
		0 /* DS-CPL, VMX, SMX, EST */ |
		0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
		F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
		F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
		F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
		0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
		F(F16C) | F(RDRAND);
	/* cpuid 0x80000001.ecx */
	const u32 kvm_cpuid_8000_0001_ecx_x86_features =
		F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
		F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
		F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
		0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) |
		F(TOPOEXT) | F(PERFCTR_CORE);

	/* cpuid 0x80000008.ebx */
	const u32 kvm_cpuid_8000_0008_ebx_x86_features =
		F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
		F(AMD_SSB_NO);

	/* cpuid 0xC0000001.edx */
	const u32 kvm_cpuid_C000_0001_edx_x86_features =
		F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
		F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
		F(PMM) | F(PMM_EN);

	/* cpuid 7.0.ebx */
	const u32 kvm_cpuid_7_0_ebx_x86_features =
		F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
		F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
		F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
		F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) |
		F(SHA_NI) | F(AVX512BW) | F(AVX512VL);

	/* cpuid 0xD.1.eax */
	const u32 kvm_cpuid_D_1_eax_x86_features =
		F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;

	/* cpuid 7.0.ecx*/
	const u32 kvm_cpuid_7_0_ecx_x86_features =
		F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ |
		F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) |
		F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) |
		F(CLDEMOTE);

	/* cpuid 7.0.edx*/
	const u32 kvm_cpuid_7_0_edx_x86_features =
		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
		F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES);

	/* all calls to cpuid_count() should be made on the same cpu */
	get_cpu();

	r = -E2BIG;

	if (*nent >= maxnent)
		goto out;

	do_cpuid_1_ent(entry, function, index);
	++*nent;

	switch (function) {
	case 0:
		entry->eax = min(entry->eax, (u32)0xd);
		break;
	case 1:
		entry->edx &= kvm_cpuid_1_edx_x86_features;
		cpuid_mask(&entry->edx, CPUID_1_EDX);
		entry->ecx &= kvm_cpuid_1_ecx_x86_features;
		cpuid_mask(&entry->ecx, CPUID_1_ECX);
		/* we support x2apic emulation even if host does not support
		 * it since we emulate x2apic in software */
		entry->ecx |= F(X2APIC);
		break;
	/* function 2 entries are STATEFUL. That is, repeated cpuid commands
	 * may return different values. This forces us to get_cpu() before
	 * issuing the first command, and also to emulate this annoying behavior
	 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
	case 2: {
		int t, times = entry->eax & 0xff;

		entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
		entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
		for (t = 1; t < times; ++t) {
			if (*nent >= maxnent)
				goto out;

			do_cpuid_1_ent(&entry[t], function, 0);
			entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
			++*nent;
		}
		break;
	}
	/* function 4 has additional index. */
	case 4: {
		int i, cache_type;

		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
		/* read more entries until cache_type is zero */
		for (i = 1; ; ++i) {
			if (*nent >= maxnent)
				goto out;

			cache_type = entry[i - 1].eax & 0x1f;
			if (!cache_type)
				break;
			do_cpuid_1_ent(&entry[i], function, i);
			entry[i].flags |=
			       KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
			++*nent;
		}
		break;
	}
	case 6: /* Thermal management */
		entry->eax = 0x4; /* allow ARAT */
		entry->ebx = 0;
		entry->ecx = 0;
		entry->edx = 0;
		break;
	case 7: {
		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
		/* Mask ebx against host capability word 9 */
		if (index == 0) {
			entry->ebx &= kvm_cpuid_7_0_ebx_x86_features;
			cpuid_mask(&entry->ebx, CPUID_7_0_EBX);
			// TSC_ADJUST is emulated
			entry->ebx |= F(TSC_ADJUST);
			entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
			cpuid_mask(&entry->ecx, CPUID_7_ECX);
			entry->ecx |= f_umip;
			/* PKU is not yet implemented for shadow paging. */
			if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
				entry->ecx &= ~F(PKU);
			entry->edx &= kvm_cpuid_7_0_edx_x86_features;
			cpuid_mask(&entry->edx, CPUID_7_EDX);
			/*
			 * We emulate ARCH_CAPABILITIES in software even
			 * if the host doesn't support it.
			 */
			entry->edx |= F(ARCH_CAPABILITIES);
		} else {
			entry->ebx = 0;
			entry->ecx = 0;
			entry->edx = 0;
		}
		entry->eax = 0;
		break;
	}
	case 9:
		break;
	case 0xa: { /* Architectural Performance Monitoring */
		struct x86_pmu_capability cap;
		union cpuid10_eax eax;
		union cpuid10_edx edx;

		perf_get_x86_pmu_capability(&cap);

		/*
		 * Only support guest architectural pmu on a host
		 * with architectural pmu.
		 */
		if (!cap.version)
			memset(&cap, 0, sizeof(cap));

		eax.split.version_id = min(cap.version, 2);
		eax.split.num_counters = cap.num_counters_gp;
		eax.split.bit_width = cap.bit_width_gp;
		eax.split.mask_length = cap.events_mask_len;

		edx.split.num_counters_fixed = cap.num_counters_fixed;
		edx.split.bit_width_fixed = cap.bit_width_fixed;
		edx.split.reserved = 0;

		entry->eax = eax.full;
		entry->ebx = cap.events_mask;
		entry->ecx = 0;
		entry->edx = edx.full;
		break;
	}
	/* function 0xb has additional index. */
	case 0xb: {
		int i, level_type;

		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
		/* read more entries until level_type is zero */
		for (i = 1; ; ++i) {
			if (*nent >= maxnent)
				goto out;

			level_type = entry[i - 1].ecx & 0xff00;
			if (!level_type)
				break;
			do_cpuid_1_ent(&entry[i], function, i);
			entry[i].flags |=
			       KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
			++*nent;
		}
		break;
	}
	case 0xd: {
		int idx, i;
		u64 supported = kvm_supported_xcr0();

		entry->eax &= supported;
		entry->ebx = xstate_required_size(supported, false);
		entry->ecx = entry->ebx;
		entry->edx &= supported >> 32;
		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
		if (!supported)
			break;

		for (idx = 1, i = 1; idx < 64; ++idx) {
			u64 mask = ((u64)1 << idx);
			if (*nent >= maxnent)
				goto out;

			do_cpuid_1_ent(&entry[i], function, idx);
			if (idx == 1) {
				entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
				cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
				entry[i].ebx = 0;
				if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
					entry[i].ebx =
						xstate_required_size(supported,
								     true);
			} else {
				if (entry[i].eax == 0 || !(supported & mask))
					continue;
				if (WARN_ON_ONCE(entry[i].ecx & 1))
					continue;
			}
			entry[i].ecx = 0;
			entry[i].edx = 0;
			entry[i].flags |=
			       KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
			++*nent;
			++i;
		}
		break;
	}
	case KVM_CPUID_SIGNATURE: {
		static const char signature[12] = "KVMKVMKVM\0\0";
		const u32 *sigptr = (const u32 *)signature;
		entry->eax = KVM_CPUID_FEATURES;
		entry->ebx = sigptr[0];
		entry->ecx = sigptr[1];
		entry->edx = sigptr[2];
		break;
	}
	case KVM_CPUID_FEATURES:
		entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
			     (1 << KVM_FEATURE_NOP_IO_DELAY) |
			     (1 << KVM_FEATURE_CLOCKSOURCE2) |
			     (1 << KVM_FEATURE_ASYNC_PF) |
			     (1 << KVM_FEATURE_PV_EOI) |
			     (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
			     (1 << KVM_FEATURE_PV_UNHALT) |
			     (1 << KVM_FEATURE_PV_TLB_FLUSH) |
			     (1 << KVM_FEATURE_ASYNC_PF_VMEXIT);

		if (sched_info_on())
			entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);

		entry->ebx = 0;
		entry->ecx = 0;
		entry->edx = 0;
		break;
	case 0x80000000:
		entry->eax = min(entry->eax, 0x8000001f);
		break;
	case 0x80000001:
		entry->edx &= kvm_cpuid_8000_0001_edx_x86_features;
		cpuid_mask(&entry->edx, CPUID_8000_0001_EDX);
		entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features;
		cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX);
		break;
	case 0x80000007: /* Advanced power management */
		/* invariant TSC is CPUID.80000007H:EDX[8] */
		entry->edx &= (1 << 8);
		/* mask against host */
		entry->edx &= boot_cpu_data.x86_power;
		entry->eax = entry->ebx = entry->ecx = 0;
		break;
	case 0x80000008: {
		unsigned g_phys_as = (entry->eax >> 16) & 0xff;
		unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
		unsigned phys_as = entry->eax & 0xff;

		if (!g_phys_as)
			g_phys_as = phys_as;
		entry->eax = g_phys_as | (virt_as << 8);
		entry->edx = 0;
		/*
		 * IBRS, IBPB and VIRT_SSBD aren't necessarily present in
		 * hardware cpuid
		 */
		if (boot_cpu_has(X86_FEATURE_AMD_IBPB))
			entry->ebx |= F(AMD_IBPB);
		if (boot_cpu_has(X86_FEATURE_AMD_IBRS))
			entry->ebx |= F(AMD_IBRS);
		if (boot_cpu_has(X86_FEATURE_VIRT_SSBD))
			entry->ebx |= F(VIRT_SSBD);
		entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
		cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
		/*
		 * The preference is to use SPEC CTRL MSR instead of the
		 * VIRT_SPEC MSR.
		 */
		if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) &&
		    !boot_cpu_has(X86_FEATURE_AMD_SSBD))
			entry->ebx |= F(VIRT_SSBD);
		break;
	}
	case 0x80000019:
		entry->ecx = entry->edx = 0;
		break;
	case 0x8000001a:
		break;
	case 0x8000001d:
		break;
	/*Add support for Centaur's CPUID instruction*/
	case 0xC0000000:
		/*Just support up to 0xC0000004 now*/
		entry->eax = min(entry->eax, 0xC0000004);
		break;
	case 0xC0000001:
		entry->edx &= kvm_cpuid_C000_0001_edx_x86_features;
		cpuid_mask(&entry->edx, CPUID_C000_0001_EDX);
		break;
	case 3: /* Processor serial number */
	case 5: /* MONITOR/MWAIT */
	case 0xC0000002:
	case 0xC0000003:
	case 0xC0000004:
	default:
		entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
		break;
	}

	kvm_x86_ops->set_supported_cpuid(function, entry);

	r = 0;

out:
	put_cpu();

	return r;
}

static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
			u32 idx, int *nent, int maxnent, unsigned int type)
{
	if (type == KVM_GET_EMULATED_CPUID)
		return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);

	return __do_cpuid_ent(entry, func, idx, nent, maxnent);
}

#undef F

struct kvm_cpuid_param {
	u32 func;
	u32 idx;
	bool has_leaf_count;
	bool (*qualifier)(const struct kvm_cpuid_param *param);
};

static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
{
	return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
}

static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
				 __u32 num_entries, unsigned int ioctl_type)
{
	int i;
	__u32 pad[3];

	if (ioctl_type != KVM_GET_EMULATED_CPUID)
		return false;

	/*
	 * We want to make sure that ->padding is being passed clean from
	 * userspace in case we want to use it for something in the future.
	 *
	 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
	 * have to give ourselves satisfied only with the emulated side. /me
	 * sheds a tear.
	 */
	for (i = 0; i < num_entries; i++) {
		if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
			return true;

		if (pad[0] || pad[1] || pad[2])
			return true;
	}
	return false;
}

int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
			    struct kvm_cpuid_entry2 __user *entries,
			    unsigned int type)
{
	struct kvm_cpuid_entry2 *cpuid_entries;
	int limit, nent = 0, r = -E2BIG, i;
	u32 func;
	static const struct kvm_cpuid_param param[] = {
		{ .func = 0, .has_leaf_count = true },
		{ .func = 0x80000000, .has_leaf_count = true },
		{ .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
		{ .func = KVM_CPUID_SIGNATURE },
		{ .func = KVM_CPUID_FEATURES },
	};

	if (cpuid->nent < 1)
		goto out;
	if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
		cpuid->nent = KVM_MAX_CPUID_ENTRIES;

	if (sanity_check_entries(entries, cpuid->nent, type))
		return -EINVAL;

	r = -ENOMEM;
	cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
	if (!cpuid_entries)
		goto out;

	r = 0;
	for (i = 0; i < ARRAY_SIZE(param); i++) {
		const struct kvm_cpuid_param *ent = &param[i];

		if (ent->qualifier && !ent->qualifier(ent))
			continue;

		r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
				&nent, cpuid->nent, type);

		if (r)
			goto out_free;

		if (!ent->has_leaf_count)
			continue;

		limit = cpuid_entries[nent - 1].eax;
		for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
			r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
				     &nent, cpuid->nent, type);

		if (r)
			goto out_free;
	}

	r = -EFAULT;
	if (copy_to_user(entries, cpuid_entries,
			 nent * sizeof(struct kvm_cpuid_entry2)))
		goto out_free;
	cpuid->nent = nent;
	r = 0;

out_free:
	vfree(cpuid_entries);
out:
	return r;
}

static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
{
	struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
	struct kvm_cpuid_entry2 *ej;
	int j = i;
	int nent = vcpu->arch.cpuid_nent;

	e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
	/* when no next entry is found, the current entry[i] is reselected */
	do {
		j = (j + 1) % nent;
		ej = &vcpu->arch.cpuid_entries[j];
	} while (ej->function != e->function);

	ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;

	return j;
}

/* find an entry with matching function, matching index (if needed), and that
 * should be read next (if it's stateful) */
static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
	u32 function, u32 index)
{
	if (e->function != function)
		return 0;
	if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
		return 0;
	if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
	    !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
		return 0;
	return 1;
}

struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
					      u32 function, u32 index)
{
	int i;
	struct kvm_cpuid_entry2 *best = NULL;

	for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
		struct kvm_cpuid_entry2 *e;

		e = &vcpu->arch.cpuid_entries[i];
		if (is_matching_cpuid_entry(e, function, index)) {
			if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
				move_to_next_stateful_cpuid_entry(vcpu, i);
			best = e;
			break;
		}
	}
	return best;
}
EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);

/*
 * If no match is found, check whether we exceed the vCPU's limit
 * and return the content of the highest valid _standard_ leaf instead.
 * This is to satisfy the CPUID specification.
 */
static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
                                                  u32 function, u32 index)
{
	struct kvm_cpuid_entry2 *maxlevel;

	maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
	if (!maxlevel || maxlevel->eax >= function)
		return NULL;
	if (function & 0x80000000) {
		maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
		if (!maxlevel)
			return NULL;
	}
	return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
}

bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
	       u32 *ecx, u32 *edx, bool check_limit)
{
	u32 function = *eax, index = *ecx;
	struct kvm_cpuid_entry2 *best;
	bool entry_found = true;

	best = kvm_find_cpuid_entry(vcpu, function, index);

	if (!best) {
		entry_found = false;
		if (!check_limit)
			goto out;

		best = check_cpuid_limit(vcpu, function, index);
	}

out:
	if (best) {
		*eax = best->eax;
		*ebx = best->ebx;
		*ecx = best->ecx;
		*edx = best->edx;
	} else
		*eax = *ebx = *ecx = *edx = 0;
	trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found);
	return entry_found;
}
EXPORT_SYMBOL_GPL(kvm_cpuid);

int kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
{
	u32 eax, ebx, ecx, edx;

	if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0))
		return 1;

	eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
	ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
	kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true);
	kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
	kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
	kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
	kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
	return kvm_skip_emulated_instruction(vcpu);
}
EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);