2 * Kernel-based Virtual Machine driver for Linux
3 * cpuid support routines
5 * derived from arch/x86/kvm/x86.c
7 * Copyright 2011 Red Hat, Inc. and/or its affiliates.
8 * Copyright IBM Corporation, 2008
10 * This work is licensed under the terms of the GNU GPL, version 2. See
11 * the COPYING file in the top-level directory.
15 #include <linux/kvm_host.h>
16 #include <linux/module.h>
17 #include <linux/vmalloc.h>
18 #include <linux/uaccess.h>
20 #include <asm/xsave.h>
26 static u32
xstate_required_size(u64 xstate_bv
)
29 u32 ret
= XSAVE_HDR_SIZE
+ XSAVE_HDR_OFFSET
;
31 xstate_bv
&= XSTATE_EXTEND_MASK
;
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
);
46 u64
kvm_supported_xcr0(void)
48 u64 xcr0
= KVM_SUPPORTED_XCR0
& host_xcr0
;
50 if (!kvm_x86_ops
->mpx_supported())
51 xcr0
&= ~(XSTATE_BNDREGS
| XSTATE_BNDCSR
);
56 void kvm_update_cpuid(struct kvm_vcpu
*vcpu
)
58 struct kvm_cpuid_entry2
*best
;
59 struct kvm_lapic
*apic
= vcpu
->arch
.apic
;
61 best
= kvm_find_cpuid_entry(vcpu
, 1, 0);
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
);
73 if (best
->ecx
& bit(X86_FEATURE_TSC_DEADLINE_TIMER
))
74 apic
->lapic_timer
.timer_mode_mask
= 3 << 17;
76 apic
->lapic_timer
.timer_mode_mask
= 1 << 17;
79 best
= kvm_find_cpuid_entry(vcpu
, 0xD, 0);
81 vcpu
->arch
.guest_supported_xcr0
= 0;
82 vcpu
->arch
.guest_xstate_size
= XSAVE_HDR_SIZE
+ XSAVE_HDR_OFFSET
;
84 vcpu
->arch
.guest_supported_xcr0
=
85 (best
->eax
| ((u64
)best
->edx
<< 32)) &
87 vcpu
->arch
.guest_xstate_size
= best
->ebx
=
88 xstate_required_size(vcpu
->arch
.xcr0
);
91 kvm_pmu_cpuid_update(vcpu
);
94 static int is_efer_nx(void)
96 unsigned long long efer
= 0;
98 rdmsrl_safe(MSR_EFER
, &efer
);
99 return efer
& EFER_NX
;
102 static void cpuid_fix_nx_cap(struct kvm_vcpu
*vcpu
)
105 struct kvm_cpuid_entry2
*e
, *entry
;
108 for (i
= 0; i
< vcpu
->arch
.cpuid_nent
; ++i
) {
109 e
= &vcpu
->arch
.cpuid_entries
[i
];
110 if (e
->function
== 0x80000001) {
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");
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
)
127 struct kvm_cpuid_entry
*cpuid_entries
;
130 if (cpuid
->nent
> KVM_MAX_CPUID_ENTRIES
)
133 cpuid_entries
= vmalloc(sizeof(struct kvm_cpuid_entry
) * cpuid
->nent
);
137 if (copy_from_user(cpuid_entries
, entries
,
138 cpuid
->nent
* sizeof(struct kvm_cpuid_entry
)))
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;
152 vcpu
->arch
.cpuid_nent
= cpuid
->nent
;
153 cpuid_fix_nx_cap(vcpu
);
155 kvm_apic_set_version(vcpu
);
156 kvm_x86_ops
->cpuid_update(vcpu
);
157 kvm_update_cpuid(vcpu
);
160 vfree(cpuid_entries
);
165 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu
*vcpu
,
166 struct kvm_cpuid2
*cpuid
,
167 struct kvm_cpuid_entry2 __user
*entries
)
172 if (cpuid
->nent
> KVM_MAX_CPUID_ENTRIES
)
175 if (copy_from_user(&vcpu
->arch
.cpuid_entries
, entries
,
176 cpuid
->nent
* sizeof(struct kvm_cpuid_entry2
)))
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
);
188 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu
*vcpu
,
189 struct kvm_cpuid2
*cpuid
,
190 struct kvm_cpuid_entry2 __user
*entries
)
195 if (cpuid
->nent
< vcpu
->arch
.cpuid_nent
)
198 if (copy_to_user(entries
, &vcpu
->arch
.cpuid_entries
,
199 vcpu
->arch
.cpuid_nent
* sizeof(struct kvm_cpuid_entry2
)))
204 cpuid
->nent
= vcpu
->arch
.cpuid_nent
;
208 static void cpuid_mask(u32
*word
, int wordnum
)
210 *word
&= boot_cpu_data
.x86_capability
[wordnum
];
213 static void do_cpuid_1_ent(struct kvm_cpuid_entry2
*entry
, u32 function
,
216 entry
->function
= function
;
217 entry
->index
= index
;
218 cpuid_count(entry
->function
, entry
->index
,
219 &entry
->eax
, &entry
->ebx
, &entry
->ecx
, &entry
->edx
);
223 #define F(x) bit(X86_FEATURE_##x)
225 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2
*entry
,
226 u32 func
, u32 index
, int *nent
, int maxnent
)
230 entry
->eax
= 1; /* only one leaf currently */
234 entry
->ecx
= F(MOVBE
);
241 entry
->function
= func
;
242 entry
->index
= index
;
247 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2
*entry
, u32 function
,
248 u32 index
, int *nent
, int maxnent
)
251 unsigned f_nx
= is_efer_nx() ? F(NX
) : 0;
253 unsigned f_gbpages
= (kvm_x86_ops
->get_lpage_level() == PT_PDPE_LEVEL
)
255 unsigned f_lm
= F(LM
);
257 unsigned f_gbpages
= 0;
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;
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
);
285 const u32 kvm_supported_word4_x86_features
=
286 F(XMM3
) | F(PCLMULQDQ
) | 0 /* DTES64, MONITOR */ |
287 0 /* DS-CPL, VMX, SMX, EST */ |
288 0 /* TM2 */ | F(SSSE3
) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
289 F(FMA
) | F(CX16
) | 0 /* xTPR Update, PDCM */ |
290 F(PCID
) | 0 /* Reserved, DCA */ | F(XMM4_1
) |
291 F(XMM4_2
) | F(X2APIC
) | F(MOVBE
) | F(POPCNT
) |
292 0 /* Reserved*/ | F(AES
) | F(XSAVE
) | 0 /* OSXSAVE */ | F(AVX
) |
294 /* cpuid 0x80000001.ecx */
295 const u32 kvm_supported_word6_x86_features
=
296 F(LAHF_LM
) | F(CMP_LEGACY
) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
297 F(CR8_LEGACY
) | F(ABM
) | F(SSE4A
) | F(MISALIGNSSE
) |
298 F(3DNOWPREFETCH
) | F(OSVW
) | 0 /* IBS */ | F(XOP
) |
299 0 /* SKINIT, WDT, LWP */ | F(FMA4
) | F(TBM
);
301 /* cpuid 0xC0000001.edx */
302 const u32 kvm_supported_word5_x86_features
=
303 F(XSTORE
) | F(XSTORE_EN
) | F(XCRYPT
) | F(XCRYPT_EN
) |
304 F(ACE2
) | F(ACE2_EN
) | F(PHE
) | F(PHE_EN
) |
308 const u32 kvm_supported_word9_x86_features
=
309 F(FSGSBASE
) | F(BMI1
) | F(HLE
) | F(AVX2
) | F(SMEP
) |
310 F(BMI2
) | F(ERMS
) | f_invpcid
| F(RTM
) | f_mpx
| F(RDSEED
) |
313 /* all calls to cpuid_count() should be made on the same cpu */
318 if (*nent
>= maxnent
)
321 do_cpuid_1_ent(entry
, function
, index
);
326 entry
->eax
= min(entry
->eax
, (u32
)0xd);
329 entry
->edx
&= kvm_supported_word0_x86_features
;
330 cpuid_mask(&entry
->edx
, 0);
331 entry
->ecx
&= kvm_supported_word4_x86_features
;
332 cpuid_mask(&entry
->ecx
, 4);
333 /* we support x2apic emulation even if host does not support
334 * it since we emulate x2apic in software */
335 entry
->ecx
|= F(X2APIC
);
337 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
338 * may return different values. This forces us to get_cpu() before
339 * issuing the first command, and also to emulate this annoying behavior
340 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
342 int t
, times
= entry
->eax
& 0xff;
344 entry
->flags
|= KVM_CPUID_FLAG_STATEFUL_FUNC
;
345 entry
->flags
|= KVM_CPUID_FLAG_STATE_READ_NEXT
;
346 for (t
= 1; t
< times
; ++t
) {
347 if (*nent
>= maxnent
)
350 do_cpuid_1_ent(&entry
[t
], function
, 0);
351 entry
[t
].flags
|= KVM_CPUID_FLAG_STATEFUL_FUNC
;
356 /* function 4 has additional index. */
360 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
361 /* read more entries until cache_type is zero */
363 if (*nent
>= maxnent
)
366 cache_type
= entry
[i
- 1].eax
& 0x1f;
369 do_cpuid_1_ent(&entry
[i
], function
, i
);
371 KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
377 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
378 /* Mask ebx against host capability word 9 */
380 entry
->ebx
&= kvm_supported_word9_x86_features
;
381 cpuid_mask(&entry
->ebx
, 9);
382 // TSC_ADJUST is emulated
383 entry
->ebx
|= F(TSC_ADJUST
);
393 case 0xa: { /* Architectural Performance Monitoring */
394 struct x86_pmu_capability cap
;
395 union cpuid10_eax eax
;
396 union cpuid10_edx edx
;
398 perf_get_x86_pmu_capability(&cap
);
401 * Only support guest architectural pmu on a host
402 * with architectural pmu.
405 memset(&cap
, 0, sizeof(cap
));
407 eax
.split
.version_id
= min(cap
.version
, 2);
408 eax
.split
.num_counters
= cap
.num_counters_gp
;
409 eax
.split
.bit_width
= cap
.bit_width_gp
;
410 eax
.split
.mask_length
= cap
.events_mask_len
;
412 edx
.split
.num_counters_fixed
= cap
.num_counters_fixed
;
413 edx
.split
.bit_width_fixed
= cap
.bit_width_fixed
;
414 edx
.split
.reserved
= 0;
416 entry
->eax
= eax
.full
;
417 entry
->ebx
= cap
.events_mask
;
419 entry
->edx
= edx
.full
;
422 /* function 0xb has additional index. */
426 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
427 /* read more entries until level_type is zero */
429 if (*nent
>= maxnent
)
432 level_type
= entry
[i
- 1].ecx
& 0xff00;
435 do_cpuid_1_ent(&entry
[i
], function
, i
);
437 KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
444 u64 supported
= kvm_supported_xcr0();
446 entry
->eax
&= supported
;
447 entry
->edx
&= supported
>> 32;
448 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
449 for (idx
= 1, i
= 1; idx
< 64; ++idx
) {
450 u64 mask
= ((u64
)1 << idx
);
451 if (*nent
>= maxnent
)
454 do_cpuid_1_ent(&entry
[i
], function
, idx
);
455 if (entry
[i
].eax
== 0 || !(supported
& mask
))
458 KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
464 case KVM_CPUID_SIGNATURE
: {
465 static const char signature
[12] = "KVMKVMKVM\0\0";
466 const u32
*sigptr
= (const u32
*)signature
;
467 entry
->eax
= KVM_CPUID_FEATURES
;
468 entry
->ebx
= sigptr
[0];
469 entry
->ecx
= sigptr
[1];
470 entry
->edx
= sigptr
[2];
473 case KVM_CPUID_FEATURES
:
474 entry
->eax
= (1 << KVM_FEATURE_CLOCKSOURCE
) |
475 (1 << KVM_FEATURE_NOP_IO_DELAY
) |
476 (1 << KVM_FEATURE_CLOCKSOURCE2
) |
477 (1 << KVM_FEATURE_ASYNC_PF
) |
478 (1 << KVM_FEATURE_PV_EOI
) |
479 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT
) |
480 (1 << KVM_FEATURE_PV_UNHALT
);
483 entry
->eax
|= (1 << KVM_FEATURE_STEAL_TIME
);
490 entry
->eax
= min(entry
->eax
, 0x8000001a);
493 entry
->edx
&= kvm_supported_word1_x86_features
;
494 cpuid_mask(&entry
->edx
, 1);
495 entry
->ecx
&= kvm_supported_word6_x86_features
;
496 cpuid_mask(&entry
->ecx
, 6);
499 unsigned g_phys_as
= (entry
->eax
>> 16) & 0xff;
500 unsigned virt_as
= max((entry
->eax
>> 8) & 0xff, 48U);
501 unsigned phys_as
= entry
->eax
& 0xff;
505 entry
->eax
= g_phys_as
| (virt_as
<< 8);
506 entry
->ebx
= entry
->edx
= 0;
510 entry
->ecx
= entry
->edx
= 0;
516 /*Add support for Centaur's CPUID instruction*/
518 /*Just support up to 0xC0000004 now*/
519 entry
->eax
= min(entry
->eax
, 0xC0000004);
522 entry
->edx
&= kvm_supported_word5_x86_features
;
523 cpuid_mask(&entry
->edx
, 5);
525 case 3: /* Processor serial number */
526 case 5: /* MONITOR/MWAIT */
527 case 6: /* Thermal management */
528 case 0x80000007: /* Advanced power management */
533 entry
->eax
= entry
->ebx
= entry
->ecx
= entry
->edx
= 0;
537 kvm_x86_ops
->set_supported_cpuid(function
, entry
);
547 static int do_cpuid_ent(struct kvm_cpuid_entry2
*entry
, u32 func
,
548 u32 idx
, int *nent
, int maxnent
, unsigned int type
)
550 if (type
== KVM_GET_EMULATED_CPUID
)
551 return __do_cpuid_ent_emulated(entry
, func
, idx
, nent
, maxnent
);
553 return __do_cpuid_ent(entry
, func
, idx
, nent
, maxnent
);
558 struct kvm_cpuid_param
{
562 bool (*qualifier
)(const struct kvm_cpuid_param
*param
);
565 static bool is_centaur_cpu(const struct kvm_cpuid_param
*param
)
567 return boot_cpu_data
.x86_vendor
== X86_VENDOR_CENTAUR
;
570 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user
*entries
,
571 __u32 num_entries
, unsigned int ioctl_type
)
576 if (ioctl_type
!= KVM_GET_EMULATED_CPUID
)
580 * We want to make sure that ->padding is being passed clean from
581 * userspace in case we want to use it for something in the future.
583 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
584 * have to give ourselves satisfied only with the emulated side. /me
587 for (i
= 0; i
< num_entries
; i
++) {
588 if (copy_from_user(pad
, entries
[i
].padding
, sizeof(pad
)))
591 if (pad
[0] || pad
[1] || pad
[2])
597 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2
*cpuid
,
598 struct kvm_cpuid_entry2 __user
*entries
,
601 struct kvm_cpuid_entry2
*cpuid_entries
;
602 int limit
, nent
= 0, r
= -E2BIG
, i
;
604 static const struct kvm_cpuid_param param
[] = {
605 { .func
= 0, .has_leaf_count
= true },
606 { .func
= 0x80000000, .has_leaf_count
= true },
607 { .func
= 0xC0000000, .qualifier
= is_centaur_cpu
, .has_leaf_count
= true },
608 { .func
= KVM_CPUID_SIGNATURE
},
609 { .func
= KVM_CPUID_FEATURES
},
614 if (cpuid
->nent
> KVM_MAX_CPUID_ENTRIES
)
615 cpuid
->nent
= KVM_MAX_CPUID_ENTRIES
;
617 if (sanity_check_entries(entries
, cpuid
->nent
, type
))
621 cpuid_entries
= vzalloc(sizeof(struct kvm_cpuid_entry2
) * cpuid
->nent
);
626 for (i
= 0; i
< ARRAY_SIZE(param
); i
++) {
627 const struct kvm_cpuid_param
*ent
= ¶m
[i
];
629 if (ent
->qualifier
&& !ent
->qualifier(ent
))
632 r
= do_cpuid_ent(&cpuid_entries
[nent
], ent
->func
, ent
->idx
,
633 &nent
, cpuid
->nent
, type
);
638 if (!ent
->has_leaf_count
)
641 limit
= cpuid_entries
[nent
- 1].eax
;
642 for (func
= ent
->func
+ 1; func
<= limit
&& nent
< cpuid
->nent
&& r
== 0; ++func
)
643 r
= do_cpuid_ent(&cpuid_entries
[nent
], func
, ent
->idx
,
644 &nent
, cpuid
->nent
, type
);
651 if (copy_to_user(entries
, cpuid_entries
,
652 nent
* sizeof(struct kvm_cpuid_entry2
)))
658 vfree(cpuid_entries
);
663 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu
*vcpu
, int i
)
665 struct kvm_cpuid_entry2
*e
= &vcpu
->arch
.cpuid_entries
[i
];
666 int j
, nent
= vcpu
->arch
.cpuid_nent
;
668 e
->flags
&= ~KVM_CPUID_FLAG_STATE_READ_NEXT
;
669 /* when no next entry is found, the current entry[i] is reselected */
670 for (j
= i
+ 1; ; j
= (j
+ 1) % nent
) {
671 struct kvm_cpuid_entry2
*ej
= &vcpu
->arch
.cpuid_entries
[j
];
672 if (ej
->function
== e
->function
) {
673 ej
->flags
|= KVM_CPUID_FLAG_STATE_READ_NEXT
;
677 return 0; /* silence gcc, even though control never reaches here */
680 /* find an entry with matching function, matching index (if needed), and that
681 * should be read next (if it's stateful) */
682 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2
*e
,
683 u32 function
, u32 index
)
685 if (e
->function
!= function
)
687 if ((e
->flags
& KVM_CPUID_FLAG_SIGNIFCANT_INDEX
) && e
->index
!= index
)
689 if ((e
->flags
& KVM_CPUID_FLAG_STATEFUL_FUNC
) &&
690 !(e
->flags
& KVM_CPUID_FLAG_STATE_READ_NEXT
))
695 struct kvm_cpuid_entry2
*kvm_find_cpuid_entry(struct kvm_vcpu
*vcpu
,
696 u32 function
, u32 index
)
699 struct kvm_cpuid_entry2
*best
= NULL
;
701 for (i
= 0; i
< vcpu
->arch
.cpuid_nent
; ++i
) {
702 struct kvm_cpuid_entry2
*e
;
704 e
= &vcpu
->arch
.cpuid_entries
[i
];
705 if (is_matching_cpuid_entry(e
, function
, index
)) {
706 if (e
->flags
& KVM_CPUID_FLAG_STATEFUL_FUNC
)
707 move_to_next_stateful_cpuid_entry(vcpu
, i
);
714 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry
);
716 int cpuid_maxphyaddr(struct kvm_vcpu
*vcpu
)
718 struct kvm_cpuid_entry2
*best
;
720 best
= kvm_find_cpuid_entry(vcpu
, 0x80000000, 0);
721 if (!best
|| best
->eax
< 0x80000008)
723 best
= kvm_find_cpuid_entry(vcpu
, 0x80000008, 0);
725 return best
->eax
& 0xff;
731 * If no match is found, check whether we exceed the vCPU's limit
732 * and return the content of the highest valid _standard_ leaf instead.
733 * This is to satisfy the CPUID specification.
735 static struct kvm_cpuid_entry2
* check_cpuid_limit(struct kvm_vcpu
*vcpu
,
736 u32 function
, u32 index
)
738 struct kvm_cpuid_entry2
*maxlevel
;
740 maxlevel
= kvm_find_cpuid_entry(vcpu
, function
& 0x80000000, 0);
741 if (!maxlevel
|| maxlevel
->eax
>= function
)
743 if (function
& 0x80000000) {
744 maxlevel
= kvm_find_cpuid_entry(vcpu
, 0, 0);
748 return kvm_find_cpuid_entry(vcpu
, maxlevel
->eax
, index
);
751 void kvm_cpuid(struct kvm_vcpu
*vcpu
, u32
*eax
, u32
*ebx
, u32
*ecx
, u32
*edx
)
753 u32 function
= *eax
, index
= *ecx
;
754 struct kvm_cpuid_entry2
*best
;
756 best
= kvm_find_cpuid_entry(vcpu
, function
, index
);
759 best
= check_cpuid_limit(vcpu
, function
, index
);
767 *eax
= *ebx
= *ecx
= *edx
= 0;
768 trace_kvm_cpuid(function
, *eax
, *ebx
, *ecx
, *edx
);
770 EXPORT_SYMBOL_GPL(kvm_cpuid
);
772 void kvm_emulate_cpuid(struct kvm_vcpu
*vcpu
)
774 u32 function
, eax
, ebx
, ecx
, edx
;
776 function
= eax
= kvm_register_read(vcpu
, VCPU_REGS_RAX
);
777 ecx
= kvm_register_read(vcpu
, VCPU_REGS_RCX
);
778 kvm_cpuid(vcpu
, &eax
, &ebx
, &ecx
, &edx
);
779 kvm_register_write(vcpu
, VCPU_REGS_RAX
, eax
);
780 kvm_register_write(vcpu
, VCPU_REGS_RBX
, ebx
);
781 kvm_register_write(vcpu
, VCPU_REGS_RCX
, ecx
);
782 kvm_register_write(vcpu
, VCPU_REGS_RDX
, edx
);
783 kvm_x86_ops
->skip_emulated_instruction(vcpu
);
785 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid
);