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
, bool compacted
)
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
, offset
;
35 cpuid_count(0xD, feature_bit
, &eax
, &ebx
, &ecx
, &edx
);
36 offset
= compacted
? ret
: ebx
;
37 ret
= max(ret
, offset
+ eax
);
47 u64
kvm_supported_xcr0(void)
49 u64 xcr0
= KVM_SUPPORTED_XCR0
& host_xcr0
;
51 if (!kvm_x86_ops
->mpx_supported())
52 xcr0
&= ~(XSTATE_BNDREGS
| XSTATE_BNDCSR
);
57 #define F(x) bit(X86_FEATURE_##x)
59 int kvm_update_cpuid(struct kvm_vcpu
*vcpu
)
61 struct kvm_cpuid_entry2
*best
;
62 struct kvm_lapic
*apic
= vcpu
->arch
.apic
;
64 best
= kvm_find_cpuid_entry(vcpu
, 1, 0);
68 /* Update OSXSAVE bit */
69 if (cpu_has_xsave
&& best
->function
== 0x1) {
70 best
->ecx
&= ~F(OSXSAVE
);
71 if (kvm_read_cr4_bits(vcpu
, X86_CR4_OSXSAVE
))
72 best
->ecx
|= F(OSXSAVE
);
76 if (best
->ecx
& F(TSC_DEADLINE_TIMER
))
77 apic
->lapic_timer
.timer_mode_mask
= 3 << 17;
79 apic
->lapic_timer
.timer_mode_mask
= 1 << 17;
82 best
= kvm_find_cpuid_entry(vcpu
, 0xD, 0);
84 vcpu
->arch
.guest_supported_xcr0
= 0;
85 vcpu
->arch
.guest_xstate_size
= XSAVE_HDR_SIZE
+ XSAVE_HDR_OFFSET
;
87 vcpu
->arch
.guest_supported_xcr0
=
88 (best
->eax
| ((u64
)best
->edx
<< 32)) &
90 vcpu
->arch
.guest_xstate_size
= best
->ebx
=
91 xstate_required_size(vcpu
->arch
.xcr0
, false);
94 best
= kvm_find_cpuid_entry(vcpu
, 0xD, 1);
95 if (best
&& (best
->eax
& (F(XSAVES
) | F(XSAVEC
))))
96 best
->ebx
= xstate_required_size(vcpu
->arch
.xcr0
, true);
99 * The existing code assumes virtual address is 48-bit in the canonical
100 * address checks; exit if it is ever changed.
102 best
= kvm_find_cpuid_entry(vcpu
, 0x80000008, 0);
103 if (best
&& ((best
->eax
& 0xff00) >> 8) != 48 &&
104 ((best
->eax
& 0xff00) >> 8) != 0)
107 /* Update physical-address width */
108 vcpu
->arch
.maxphyaddr
= cpuid_query_maxphyaddr(vcpu
);
110 kvm_pmu_cpuid_update(vcpu
);
114 static int is_efer_nx(void)
116 unsigned long long efer
= 0;
118 rdmsrl_safe(MSR_EFER
, &efer
);
119 return efer
& EFER_NX
;
122 static void cpuid_fix_nx_cap(struct kvm_vcpu
*vcpu
)
125 struct kvm_cpuid_entry2
*e
, *entry
;
128 for (i
= 0; i
< vcpu
->arch
.cpuid_nent
; ++i
) {
129 e
= &vcpu
->arch
.cpuid_entries
[i
];
130 if (e
->function
== 0x80000001) {
135 if (entry
&& (entry
->edx
& F(NX
)) && !is_efer_nx()) {
136 entry
->edx
&= ~F(NX
);
137 printk(KERN_INFO
"kvm: guest NX capability removed\n");
141 int cpuid_query_maxphyaddr(struct kvm_vcpu
*vcpu
)
143 struct kvm_cpuid_entry2
*best
;
145 best
= kvm_find_cpuid_entry(vcpu
, 0x80000000, 0);
146 if (!best
|| best
->eax
< 0x80000008)
148 best
= kvm_find_cpuid_entry(vcpu
, 0x80000008, 0);
150 return best
->eax
& 0xff;
154 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr
);
156 /* when an old userspace process fills a new kernel module */
157 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu
*vcpu
,
158 struct kvm_cpuid
*cpuid
,
159 struct kvm_cpuid_entry __user
*entries
)
162 struct kvm_cpuid_entry
*cpuid_entries
;
165 if (cpuid
->nent
> KVM_MAX_CPUID_ENTRIES
)
168 cpuid_entries
= vmalloc(sizeof(struct kvm_cpuid_entry
) * cpuid
->nent
);
172 if (copy_from_user(cpuid_entries
, entries
,
173 cpuid
->nent
* sizeof(struct kvm_cpuid_entry
)))
175 for (i
= 0; i
< cpuid
->nent
; i
++) {
176 vcpu
->arch
.cpuid_entries
[i
].function
= cpuid_entries
[i
].function
;
177 vcpu
->arch
.cpuid_entries
[i
].eax
= cpuid_entries
[i
].eax
;
178 vcpu
->arch
.cpuid_entries
[i
].ebx
= cpuid_entries
[i
].ebx
;
179 vcpu
->arch
.cpuid_entries
[i
].ecx
= cpuid_entries
[i
].ecx
;
180 vcpu
->arch
.cpuid_entries
[i
].edx
= cpuid_entries
[i
].edx
;
181 vcpu
->arch
.cpuid_entries
[i
].index
= 0;
182 vcpu
->arch
.cpuid_entries
[i
].flags
= 0;
183 vcpu
->arch
.cpuid_entries
[i
].padding
[0] = 0;
184 vcpu
->arch
.cpuid_entries
[i
].padding
[1] = 0;
185 vcpu
->arch
.cpuid_entries
[i
].padding
[2] = 0;
187 vcpu
->arch
.cpuid_nent
= cpuid
->nent
;
188 cpuid_fix_nx_cap(vcpu
);
189 kvm_apic_set_version(vcpu
);
190 kvm_x86_ops
->cpuid_update(vcpu
);
191 r
= kvm_update_cpuid(vcpu
);
194 vfree(cpuid_entries
);
199 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu
*vcpu
,
200 struct kvm_cpuid2
*cpuid
,
201 struct kvm_cpuid_entry2 __user
*entries
)
206 if (cpuid
->nent
> KVM_MAX_CPUID_ENTRIES
)
209 if (copy_from_user(&vcpu
->arch
.cpuid_entries
, entries
,
210 cpuid
->nent
* sizeof(struct kvm_cpuid_entry2
)))
212 vcpu
->arch
.cpuid_nent
= cpuid
->nent
;
213 kvm_apic_set_version(vcpu
);
214 kvm_x86_ops
->cpuid_update(vcpu
);
215 r
= kvm_update_cpuid(vcpu
);
220 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu
*vcpu
,
221 struct kvm_cpuid2
*cpuid
,
222 struct kvm_cpuid_entry2 __user
*entries
)
227 if (cpuid
->nent
< vcpu
->arch
.cpuid_nent
)
230 if (copy_to_user(entries
, &vcpu
->arch
.cpuid_entries
,
231 vcpu
->arch
.cpuid_nent
* sizeof(struct kvm_cpuid_entry2
)))
236 cpuid
->nent
= vcpu
->arch
.cpuid_nent
;
240 static void cpuid_mask(u32
*word
, int wordnum
)
242 *word
&= boot_cpu_data
.x86_capability
[wordnum
];
245 static void do_cpuid_1_ent(struct kvm_cpuid_entry2
*entry
, u32 function
,
248 entry
->function
= function
;
249 entry
->index
= index
;
250 cpuid_count(entry
->function
, entry
->index
,
251 &entry
->eax
, &entry
->ebx
, &entry
->ecx
, &entry
->edx
);
255 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2
*entry
,
256 u32 func
, u32 index
, int *nent
, int maxnent
)
260 entry
->eax
= 1; /* only one leaf currently */
264 entry
->ecx
= F(MOVBE
);
271 entry
->function
= func
;
272 entry
->index
= index
;
277 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2
*entry
, u32 function
,
278 u32 index
, int *nent
, int maxnent
)
281 unsigned f_nx
= is_efer_nx() ? F(NX
) : 0;
283 unsigned f_gbpages
= (kvm_x86_ops
->get_lpage_level() == PT_PDPE_LEVEL
)
285 unsigned f_lm
= F(LM
);
287 unsigned f_gbpages
= 0;
290 unsigned f_rdtscp
= kvm_x86_ops
->rdtscp_supported() ? F(RDTSCP
) : 0;
291 unsigned f_invpcid
= kvm_x86_ops
->invpcid_supported() ? F(INVPCID
) : 0;
292 unsigned f_mpx
= kvm_x86_ops
->mpx_supported() ? F(MPX
) : 0;
293 unsigned f_xsaves
= kvm_x86_ops
->xsaves_supported() ? F(XSAVES
) : 0;
296 const u32 kvm_supported_word0_x86_features
=
297 F(FPU
) | F(VME
) | F(DE
) | F(PSE
) |
298 F(TSC
) | F(MSR
) | F(PAE
) | F(MCE
) |
299 F(CX8
) | F(APIC
) | 0 /* Reserved */ | F(SEP
) |
300 F(MTRR
) | F(PGE
) | F(MCA
) | F(CMOV
) |
301 F(PAT
) | F(PSE36
) | 0 /* PSN */ | F(CLFLUSH
) |
302 0 /* Reserved, DS, ACPI */ | F(MMX
) |
303 F(FXSR
) | F(XMM
) | F(XMM2
) | F(SELFSNOOP
) |
304 0 /* HTT, TM, Reserved, PBE */;
305 /* cpuid 0x80000001.edx */
306 const u32 kvm_supported_word1_x86_features
=
307 F(FPU
) | F(VME
) | F(DE
) | F(PSE
) |
308 F(TSC
) | F(MSR
) | F(PAE
) | F(MCE
) |
309 F(CX8
) | F(APIC
) | 0 /* Reserved */ | F(SYSCALL
) |
310 F(MTRR
) | F(PGE
) | F(MCA
) | F(CMOV
) |
311 F(PAT
) | F(PSE36
) | 0 /* Reserved */ |
312 f_nx
| 0 /* Reserved */ | F(MMXEXT
) | F(MMX
) |
313 F(FXSR
) | F(FXSR_OPT
) | f_gbpages
| f_rdtscp
|
314 0 /* Reserved */ | f_lm
| F(3DNOWEXT
) | F(3DNOW
);
316 const u32 kvm_supported_word4_x86_features
=
317 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
318 * but *not* advertised to guests via CPUID ! */
319 F(XMM3
) | F(PCLMULQDQ
) | 0 /* DTES64, MONITOR */ |
320 0 /* DS-CPL, VMX, SMX, EST */ |
321 0 /* TM2 */ | F(SSSE3
) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
322 F(FMA
) | F(CX16
) | 0 /* xTPR Update, PDCM */ |
323 F(PCID
) | 0 /* Reserved, DCA */ | F(XMM4_1
) |
324 F(XMM4_2
) | F(X2APIC
) | F(MOVBE
) | F(POPCNT
) |
325 0 /* Reserved*/ | F(AES
) | F(XSAVE
) | 0 /* OSXSAVE */ | F(AVX
) |
327 /* cpuid 0x80000001.ecx */
328 const u32 kvm_supported_word6_x86_features
=
329 F(LAHF_LM
) | F(CMP_LEGACY
) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
330 F(CR8_LEGACY
) | F(ABM
) | F(SSE4A
) | F(MISALIGNSSE
) |
331 F(3DNOWPREFETCH
) | F(OSVW
) | 0 /* IBS */ | F(XOP
) |
332 0 /* SKINIT, WDT, LWP */ | F(FMA4
) | F(TBM
);
334 /* cpuid 0xC0000001.edx */
335 const u32 kvm_supported_word5_x86_features
=
336 F(XSTORE
) | F(XSTORE_EN
) | F(XCRYPT
) | F(XCRYPT_EN
) |
337 F(ACE2
) | F(ACE2_EN
) | F(PHE
) | F(PHE_EN
) |
341 const u32 kvm_supported_word9_x86_features
=
342 F(FSGSBASE
) | F(BMI1
) | F(HLE
) | F(AVX2
) | F(SMEP
) |
343 F(BMI2
) | F(ERMS
) | f_invpcid
| F(RTM
) | f_mpx
| F(RDSEED
) |
344 F(ADX
) | F(SMAP
) | F(AVX512F
) | F(AVX512PF
) | F(AVX512ER
) |
347 /* cpuid 0xD.1.eax */
348 const u32 kvm_supported_word10_x86_features
=
349 F(XSAVEOPT
) | F(XSAVEC
) | F(XGETBV1
) | f_xsaves
;
351 /* all calls to cpuid_count() should be made on the same cpu */
356 if (*nent
>= maxnent
)
359 do_cpuid_1_ent(entry
, function
, index
);
364 entry
->eax
= min(entry
->eax
, (u32
)0xd);
367 entry
->edx
&= kvm_supported_word0_x86_features
;
368 cpuid_mask(&entry
->edx
, 0);
369 entry
->ecx
&= kvm_supported_word4_x86_features
;
370 cpuid_mask(&entry
->ecx
, 4);
371 /* we support x2apic emulation even if host does not support
372 * it since we emulate x2apic in software */
373 entry
->ecx
|= F(X2APIC
);
375 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
376 * may return different values. This forces us to get_cpu() before
377 * issuing the first command, and also to emulate this annoying behavior
378 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
380 int t
, times
= entry
->eax
& 0xff;
382 entry
->flags
|= KVM_CPUID_FLAG_STATEFUL_FUNC
;
383 entry
->flags
|= KVM_CPUID_FLAG_STATE_READ_NEXT
;
384 for (t
= 1; t
< times
; ++t
) {
385 if (*nent
>= maxnent
)
388 do_cpuid_1_ent(&entry
[t
], function
, 0);
389 entry
[t
].flags
|= KVM_CPUID_FLAG_STATEFUL_FUNC
;
394 /* function 4 has additional index. */
398 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
399 /* read more entries until cache_type is zero */
401 if (*nent
>= maxnent
)
404 cache_type
= entry
[i
- 1].eax
& 0x1f;
407 do_cpuid_1_ent(&entry
[i
], function
, i
);
409 KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
415 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
416 /* Mask ebx against host capability word 9 */
418 entry
->ebx
&= kvm_supported_word9_x86_features
;
419 cpuid_mask(&entry
->ebx
, 9);
420 // TSC_ADJUST is emulated
421 entry
->ebx
|= F(TSC_ADJUST
);
431 case 0xa: { /* Architectural Performance Monitoring */
432 struct x86_pmu_capability cap
;
433 union cpuid10_eax eax
;
434 union cpuid10_edx edx
;
436 perf_get_x86_pmu_capability(&cap
);
439 * Only support guest architectural pmu on a host
440 * with architectural pmu.
443 memset(&cap
, 0, sizeof(cap
));
445 eax
.split
.version_id
= min(cap
.version
, 2);
446 eax
.split
.num_counters
= cap
.num_counters_gp
;
447 eax
.split
.bit_width
= cap
.bit_width_gp
;
448 eax
.split
.mask_length
= cap
.events_mask_len
;
450 edx
.split
.num_counters_fixed
= cap
.num_counters_fixed
;
451 edx
.split
.bit_width_fixed
= cap
.bit_width_fixed
;
452 edx
.split
.reserved
= 0;
454 entry
->eax
= eax
.full
;
455 entry
->ebx
= cap
.events_mask
;
457 entry
->edx
= edx
.full
;
460 /* function 0xb has additional index. */
464 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
465 /* read more entries until level_type is zero */
467 if (*nent
>= maxnent
)
470 level_type
= entry
[i
- 1].ecx
& 0xff00;
473 do_cpuid_1_ent(&entry
[i
], function
, i
);
475 KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
482 u64 supported
= kvm_supported_xcr0();
484 entry
->eax
&= supported
;
485 entry
->ebx
= xstate_required_size(supported
, false);
486 entry
->ecx
= entry
->ebx
;
487 entry
->edx
&= supported
>> 32;
488 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
492 for (idx
= 1, i
= 1; idx
< 64; ++idx
) {
493 u64 mask
= ((u64
)1 << idx
);
494 if (*nent
>= maxnent
)
497 do_cpuid_1_ent(&entry
[i
], function
, idx
);
499 entry
[i
].eax
&= kvm_supported_word10_x86_features
;
501 if (entry
[i
].eax
& (F(XSAVES
)|F(XSAVEC
)))
503 xstate_required_size(supported
,
506 if (entry
[i
].eax
== 0 || !(supported
& mask
))
508 if (WARN_ON_ONCE(entry
[i
].ecx
& 1))
514 KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
520 case KVM_CPUID_SIGNATURE
: {
521 static const char signature
[12] = "KVMKVMKVM\0\0";
522 const u32
*sigptr
= (const u32
*)signature
;
523 entry
->eax
= KVM_CPUID_FEATURES
;
524 entry
->ebx
= sigptr
[0];
525 entry
->ecx
= sigptr
[1];
526 entry
->edx
= sigptr
[2];
529 case KVM_CPUID_FEATURES
:
530 entry
->eax
= (1 << KVM_FEATURE_CLOCKSOURCE
) |
531 (1 << KVM_FEATURE_NOP_IO_DELAY
) |
532 (1 << KVM_FEATURE_CLOCKSOURCE2
) |
533 (1 << KVM_FEATURE_ASYNC_PF
) |
534 (1 << KVM_FEATURE_PV_EOI
) |
535 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT
) |
536 (1 << KVM_FEATURE_PV_UNHALT
);
539 entry
->eax
|= (1 << KVM_FEATURE_STEAL_TIME
);
546 entry
->eax
= min(entry
->eax
, 0x8000001a);
549 entry
->edx
&= kvm_supported_word1_x86_features
;
550 cpuid_mask(&entry
->edx
, 1);
551 entry
->ecx
&= kvm_supported_word6_x86_features
;
552 cpuid_mask(&entry
->ecx
, 6);
554 case 0x80000007: /* Advanced power management */
555 /* invariant TSC is CPUID.80000007H:EDX[8] */
556 entry
->edx
&= (1 << 8);
557 /* mask against host */
558 entry
->edx
&= boot_cpu_data
.x86_power
;
559 entry
->eax
= entry
->ebx
= entry
->ecx
= 0;
562 unsigned g_phys_as
= (entry
->eax
>> 16) & 0xff;
563 unsigned virt_as
= max((entry
->eax
>> 8) & 0xff, 48U);
564 unsigned phys_as
= entry
->eax
& 0xff;
568 entry
->eax
= g_phys_as
| (virt_as
<< 8);
569 entry
->ebx
= entry
->edx
= 0;
573 entry
->ecx
= entry
->edx
= 0;
579 /*Add support for Centaur's CPUID instruction*/
581 /*Just support up to 0xC0000004 now*/
582 entry
->eax
= min(entry
->eax
, 0xC0000004);
585 entry
->edx
&= kvm_supported_word5_x86_features
;
586 cpuid_mask(&entry
->edx
, 5);
588 case 3: /* Processor serial number */
589 case 5: /* MONITOR/MWAIT */
590 case 6: /* Thermal management */
595 entry
->eax
= entry
->ebx
= entry
->ecx
= entry
->edx
= 0;
599 kvm_x86_ops
->set_supported_cpuid(function
, entry
);
609 static int do_cpuid_ent(struct kvm_cpuid_entry2
*entry
, u32 func
,
610 u32 idx
, int *nent
, int maxnent
, unsigned int type
)
612 if (type
== KVM_GET_EMULATED_CPUID
)
613 return __do_cpuid_ent_emulated(entry
, func
, idx
, nent
, maxnent
);
615 return __do_cpuid_ent(entry
, func
, idx
, nent
, maxnent
);
620 struct kvm_cpuid_param
{
624 bool (*qualifier
)(const struct kvm_cpuid_param
*param
);
627 static bool is_centaur_cpu(const struct kvm_cpuid_param
*param
)
629 return boot_cpu_data
.x86_vendor
== X86_VENDOR_CENTAUR
;
632 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user
*entries
,
633 __u32 num_entries
, unsigned int ioctl_type
)
638 if (ioctl_type
!= KVM_GET_EMULATED_CPUID
)
642 * We want to make sure that ->padding is being passed clean from
643 * userspace in case we want to use it for something in the future.
645 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
646 * have to give ourselves satisfied only with the emulated side. /me
649 for (i
= 0; i
< num_entries
; i
++) {
650 if (copy_from_user(pad
, entries
[i
].padding
, sizeof(pad
)))
653 if (pad
[0] || pad
[1] || pad
[2])
659 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2
*cpuid
,
660 struct kvm_cpuid_entry2 __user
*entries
,
663 struct kvm_cpuid_entry2
*cpuid_entries
;
664 int limit
, nent
= 0, r
= -E2BIG
, i
;
666 static const struct kvm_cpuid_param param
[] = {
667 { .func
= 0, .has_leaf_count
= true },
668 { .func
= 0x80000000, .has_leaf_count
= true },
669 { .func
= 0xC0000000, .qualifier
= is_centaur_cpu
, .has_leaf_count
= true },
670 { .func
= KVM_CPUID_SIGNATURE
},
671 { .func
= KVM_CPUID_FEATURES
},
676 if (cpuid
->nent
> KVM_MAX_CPUID_ENTRIES
)
677 cpuid
->nent
= KVM_MAX_CPUID_ENTRIES
;
679 if (sanity_check_entries(entries
, cpuid
->nent
, type
))
683 cpuid_entries
= vzalloc(sizeof(struct kvm_cpuid_entry2
) * cpuid
->nent
);
688 for (i
= 0; i
< ARRAY_SIZE(param
); i
++) {
689 const struct kvm_cpuid_param
*ent
= ¶m
[i
];
691 if (ent
->qualifier
&& !ent
->qualifier(ent
))
694 r
= do_cpuid_ent(&cpuid_entries
[nent
], ent
->func
, ent
->idx
,
695 &nent
, cpuid
->nent
, type
);
700 if (!ent
->has_leaf_count
)
703 limit
= cpuid_entries
[nent
- 1].eax
;
704 for (func
= ent
->func
+ 1; func
<= limit
&& nent
< cpuid
->nent
&& r
== 0; ++func
)
705 r
= do_cpuid_ent(&cpuid_entries
[nent
], func
, ent
->idx
,
706 &nent
, cpuid
->nent
, type
);
713 if (copy_to_user(entries
, cpuid_entries
,
714 nent
* sizeof(struct kvm_cpuid_entry2
)))
720 vfree(cpuid_entries
);
725 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu
*vcpu
, int i
)
727 struct kvm_cpuid_entry2
*e
= &vcpu
->arch
.cpuid_entries
[i
];
728 int j
, nent
= vcpu
->arch
.cpuid_nent
;
730 e
->flags
&= ~KVM_CPUID_FLAG_STATE_READ_NEXT
;
731 /* when no next entry is found, the current entry[i] is reselected */
732 for (j
= i
+ 1; ; j
= (j
+ 1) % nent
) {
733 struct kvm_cpuid_entry2
*ej
= &vcpu
->arch
.cpuid_entries
[j
];
734 if (ej
->function
== e
->function
) {
735 ej
->flags
|= KVM_CPUID_FLAG_STATE_READ_NEXT
;
739 return 0; /* silence gcc, even though control never reaches here */
742 /* find an entry with matching function, matching index (if needed), and that
743 * should be read next (if it's stateful) */
744 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2
*e
,
745 u32 function
, u32 index
)
747 if (e
->function
!= function
)
749 if ((e
->flags
& KVM_CPUID_FLAG_SIGNIFCANT_INDEX
) && e
->index
!= index
)
751 if ((e
->flags
& KVM_CPUID_FLAG_STATEFUL_FUNC
) &&
752 !(e
->flags
& KVM_CPUID_FLAG_STATE_READ_NEXT
))
757 struct kvm_cpuid_entry2
*kvm_find_cpuid_entry(struct kvm_vcpu
*vcpu
,
758 u32 function
, u32 index
)
761 struct kvm_cpuid_entry2
*best
= NULL
;
763 for (i
= 0; i
< vcpu
->arch
.cpuid_nent
; ++i
) {
764 struct kvm_cpuid_entry2
*e
;
766 e
= &vcpu
->arch
.cpuid_entries
[i
];
767 if (is_matching_cpuid_entry(e
, function
, index
)) {
768 if (e
->flags
& KVM_CPUID_FLAG_STATEFUL_FUNC
)
769 move_to_next_stateful_cpuid_entry(vcpu
, i
);
776 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry
);
779 * If no match is found, check whether we exceed the vCPU's limit
780 * and return the content of the highest valid _standard_ leaf instead.
781 * This is to satisfy the CPUID specification.
783 static struct kvm_cpuid_entry2
* check_cpuid_limit(struct kvm_vcpu
*vcpu
,
784 u32 function
, u32 index
)
786 struct kvm_cpuid_entry2
*maxlevel
;
788 maxlevel
= kvm_find_cpuid_entry(vcpu
, function
& 0x80000000, 0);
789 if (!maxlevel
|| maxlevel
->eax
>= function
)
791 if (function
& 0x80000000) {
792 maxlevel
= kvm_find_cpuid_entry(vcpu
, 0, 0);
796 return kvm_find_cpuid_entry(vcpu
, maxlevel
->eax
, index
);
799 void kvm_cpuid(struct kvm_vcpu
*vcpu
, u32
*eax
, u32
*ebx
, u32
*ecx
, u32
*edx
)
801 u32 function
= *eax
, index
= *ecx
;
802 struct kvm_cpuid_entry2
*best
;
804 best
= kvm_find_cpuid_entry(vcpu
, function
, index
);
807 best
= check_cpuid_limit(vcpu
, function
, index
);
810 * Perfmon not yet supported for L2 guest.
812 if (is_guest_mode(vcpu
) && function
== 0xa)
821 *eax
= *ebx
= *ecx
= *edx
= 0;
822 trace_kvm_cpuid(function
, *eax
, *ebx
, *ecx
, *edx
);
824 EXPORT_SYMBOL_GPL(kvm_cpuid
);
826 void kvm_emulate_cpuid(struct kvm_vcpu
*vcpu
)
828 u32 function
, eax
, ebx
, ecx
, edx
;
830 function
= eax
= kvm_register_read(vcpu
, VCPU_REGS_RAX
);
831 ecx
= kvm_register_read(vcpu
, VCPU_REGS_RCX
);
832 kvm_cpuid(vcpu
, &eax
, &ebx
, &ecx
, &edx
);
833 kvm_register_write(vcpu
, VCPU_REGS_RAX
, eax
);
834 kvm_register_write(vcpu
, VCPU_REGS_RBX
, ebx
);
835 kvm_register_write(vcpu
, VCPU_REGS_RCX
, ecx
);
836 kvm_register_write(vcpu
, VCPU_REGS_RDX
, edx
);
837 kvm_x86_ops
->skip_emulated_instruction(vcpu
);
839 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid
);