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/export.h>
17 #include <linux/vmalloc.h>
18 #include <linux/uaccess.h>
19 #include <asm/processor.h>
20 #include <asm/fpu/internal.h> /* For use_eager_fpu. Ugh! */
22 #include <asm/fpu/xstate.h>
29 static u32
xstate_required_size(u64 xstate_bv
, bool compacted
)
32 u32 ret
= XSAVE_HDR_SIZE
+ XSAVE_HDR_OFFSET
;
34 xstate_bv
&= XFEATURE_MASK_EXTEND
;
36 if (xstate_bv
& 0x1) {
37 u32 eax
, ebx
, ecx
, edx
, offset
;
38 cpuid_count(0xD, feature_bit
, &eax
, &ebx
, &ecx
, &edx
);
39 offset
= compacted
? ret
: ebx
;
40 ret
= max(ret
, offset
+ eax
);
50 bool kvm_mpx_supported(void)
52 return ((host_xcr0
& (XFEATURE_MASK_BNDREGS
| XFEATURE_MASK_BNDCSR
))
53 && kvm_x86_ops
->mpx_supported());
55 EXPORT_SYMBOL_GPL(kvm_mpx_supported
);
57 u64
kvm_supported_xcr0(void)
59 u64 xcr0
= KVM_SUPPORTED_XCR0
& host_xcr0
;
61 if (!kvm_mpx_supported())
62 xcr0
&= ~(XFEATURE_MASK_BNDREGS
| XFEATURE_MASK_BNDCSR
);
67 #define F(x) bit(X86_FEATURE_##x)
69 /* These are scattered features in cpufeatures.h. */
70 #define KVM_CPUID_BIT_AVX512_4VNNIW 2
71 #define KVM_CPUID_BIT_AVX512_4FMAPS 3
72 #define KF(x) bit(KVM_CPUID_BIT_##x)
74 int kvm_update_cpuid(struct kvm_vcpu
*vcpu
)
76 struct kvm_cpuid_entry2
*best
;
77 struct kvm_lapic
*apic
= vcpu
->arch
.apic
;
79 best
= kvm_find_cpuid_entry(vcpu
, 1, 0);
83 /* Update OSXSAVE bit */
84 if (boot_cpu_has(X86_FEATURE_XSAVE
) && best
->function
== 0x1) {
85 best
->ecx
&= ~F(OSXSAVE
);
86 if (kvm_read_cr4_bits(vcpu
, X86_CR4_OSXSAVE
))
87 best
->ecx
|= F(OSXSAVE
);
90 best
->edx
&= ~F(APIC
);
91 if (vcpu
->arch
.apic_base
& MSR_IA32_APICBASE_ENABLE
)
95 if (best
->ecx
& F(TSC_DEADLINE_TIMER
))
96 apic
->lapic_timer
.timer_mode_mask
= 3 << 17;
98 apic
->lapic_timer
.timer_mode_mask
= 1 << 17;
101 best
= kvm_find_cpuid_entry(vcpu
, 7, 0);
103 /* Update OSPKE bit */
104 if (boot_cpu_has(X86_FEATURE_PKU
) && best
->function
== 0x7) {
105 best
->ecx
&= ~F(OSPKE
);
106 if (kvm_read_cr4_bits(vcpu
, X86_CR4_PKE
))
107 best
->ecx
|= F(OSPKE
);
111 best
= kvm_find_cpuid_entry(vcpu
, 0xD, 0);
113 vcpu
->arch
.guest_supported_xcr0
= 0;
114 vcpu
->arch
.guest_xstate_size
= XSAVE_HDR_SIZE
+ XSAVE_HDR_OFFSET
;
116 vcpu
->arch
.guest_supported_xcr0
=
117 (best
->eax
| ((u64
)best
->edx
<< 32)) &
118 kvm_supported_xcr0();
119 vcpu
->arch
.guest_xstate_size
= best
->ebx
=
120 xstate_required_size(vcpu
->arch
.xcr0
, false);
123 best
= kvm_find_cpuid_entry(vcpu
, 0xD, 1);
124 if (best
&& (best
->eax
& (F(XSAVES
) | F(XSAVEC
))))
125 best
->ebx
= xstate_required_size(vcpu
->arch
.xcr0
, true);
128 kvm_x86_ops
->fpu_activate(vcpu
);
131 * The existing code assumes virtual address is 48-bit in the canonical
132 * address checks; exit if it is ever changed.
134 best
= kvm_find_cpuid_entry(vcpu
, 0x80000008, 0);
135 if (best
&& ((best
->eax
& 0xff00) >> 8) != 48 &&
136 ((best
->eax
& 0xff00) >> 8) != 0)
139 /* Update physical-address width */
140 vcpu
->arch
.maxphyaddr
= cpuid_query_maxphyaddr(vcpu
);
142 kvm_pmu_refresh(vcpu
);
146 static int is_efer_nx(void)
148 unsigned long long efer
= 0;
150 rdmsrl_safe(MSR_EFER
, &efer
);
151 return efer
& EFER_NX
;
154 static void cpuid_fix_nx_cap(struct kvm_vcpu
*vcpu
)
157 struct kvm_cpuid_entry2
*e
, *entry
;
160 for (i
= 0; i
< vcpu
->arch
.cpuid_nent
; ++i
) {
161 e
= &vcpu
->arch
.cpuid_entries
[i
];
162 if (e
->function
== 0x80000001) {
167 if (entry
&& (entry
->edx
& F(NX
)) && !is_efer_nx()) {
168 entry
->edx
&= ~F(NX
);
169 printk(KERN_INFO
"kvm: guest NX capability removed\n");
173 int cpuid_query_maxphyaddr(struct kvm_vcpu
*vcpu
)
175 struct kvm_cpuid_entry2
*best
;
177 best
= kvm_find_cpuid_entry(vcpu
, 0x80000000, 0);
178 if (!best
|| best
->eax
< 0x80000008)
180 best
= kvm_find_cpuid_entry(vcpu
, 0x80000008, 0);
182 return best
->eax
& 0xff;
186 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr
);
188 /* when an old userspace process fills a new kernel module */
189 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu
*vcpu
,
190 struct kvm_cpuid
*cpuid
,
191 struct kvm_cpuid_entry __user
*entries
)
194 struct kvm_cpuid_entry
*cpuid_entries
= NULL
;
197 if (cpuid
->nent
> KVM_MAX_CPUID_ENTRIES
)
201 cpuid_entries
= vmalloc(sizeof(struct kvm_cpuid_entry
) *
206 if (copy_from_user(cpuid_entries
, entries
,
207 cpuid
->nent
* sizeof(struct kvm_cpuid_entry
)))
210 for (i
= 0; i
< cpuid
->nent
; i
++) {
211 vcpu
->arch
.cpuid_entries
[i
].function
= cpuid_entries
[i
].function
;
212 vcpu
->arch
.cpuid_entries
[i
].eax
= cpuid_entries
[i
].eax
;
213 vcpu
->arch
.cpuid_entries
[i
].ebx
= cpuid_entries
[i
].ebx
;
214 vcpu
->arch
.cpuid_entries
[i
].ecx
= cpuid_entries
[i
].ecx
;
215 vcpu
->arch
.cpuid_entries
[i
].edx
= cpuid_entries
[i
].edx
;
216 vcpu
->arch
.cpuid_entries
[i
].index
= 0;
217 vcpu
->arch
.cpuid_entries
[i
].flags
= 0;
218 vcpu
->arch
.cpuid_entries
[i
].padding
[0] = 0;
219 vcpu
->arch
.cpuid_entries
[i
].padding
[1] = 0;
220 vcpu
->arch
.cpuid_entries
[i
].padding
[2] = 0;
222 vcpu
->arch
.cpuid_nent
= cpuid
->nent
;
223 cpuid_fix_nx_cap(vcpu
);
224 kvm_apic_set_version(vcpu
);
225 kvm_x86_ops
->cpuid_update(vcpu
);
226 r
= kvm_update_cpuid(vcpu
);
229 vfree(cpuid_entries
);
233 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu
*vcpu
,
234 struct kvm_cpuid2
*cpuid
,
235 struct kvm_cpuid_entry2 __user
*entries
)
240 if (cpuid
->nent
> KVM_MAX_CPUID_ENTRIES
)
243 if (copy_from_user(&vcpu
->arch
.cpuid_entries
, entries
,
244 cpuid
->nent
* sizeof(struct kvm_cpuid_entry2
)))
246 vcpu
->arch
.cpuid_nent
= cpuid
->nent
;
247 kvm_apic_set_version(vcpu
);
248 kvm_x86_ops
->cpuid_update(vcpu
);
249 r
= kvm_update_cpuid(vcpu
);
254 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu
*vcpu
,
255 struct kvm_cpuid2
*cpuid
,
256 struct kvm_cpuid_entry2 __user
*entries
)
261 if (cpuid
->nent
< vcpu
->arch
.cpuid_nent
)
264 if (copy_to_user(entries
, &vcpu
->arch
.cpuid_entries
,
265 vcpu
->arch
.cpuid_nent
* sizeof(struct kvm_cpuid_entry2
)))
270 cpuid
->nent
= vcpu
->arch
.cpuid_nent
;
274 static void cpuid_mask(u32
*word
, int wordnum
)
276 *word
&= boot_cpu_data
.x86_capability
[wordnum
];
279 static void do_cpuid_1_ent(struct kvm_cpuid_entry2
*entry
, u32 function
,
282 entry
->function
= function
;
283 entry
->index
= index
;
284 cpuid_count(entry
->function
, entry
->index
,
285 &entry
->eax
, &entry
->ebx
, &entry
->ecx
, &entry
->edx
);
289 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2
*entry
,
290 u32 func
, u32 index
, int *nent
, int maxnent
)
294 entry
->eax
= 1; /* only one leaf currently */
298 entry
->ecx
= F(MOVBE
);
305 entry
->function
= func
;
306 entry
->index
= index
;
311 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2
*entry
, u32 function
,
312 u32 index
, int *nent
, int maxnent
)
315 unsigned f_nx
= is_efer_nx() ? F(NX
) : 0;
317 unsigned f_gbpages
= (kvm_x86_ops
->get_lpage_level() == PT_PDPE_LEVEL
)
319 unsigned f_lm
= F(LM
);
321 unsigned f_gbpages
= 0;
324 unsigned f_rdtscp
= kvm_x86_ops
->rdtscp_supported() ? F(RDTSCP
) : 0;
325 unsigned f_invpcid
= kvm_x86_ops
->invpcid_supported() ? F(INVPCID
) : 0;
326 unsigned f_mpx
= kvm_mpx_supported() ? F(MPX
) : 0;
327 unsigned f_xsaves
= kvm_x86_ops
->xsaves_supported() ? F(XSAVES
) : 0;
330 const u32 kvm_cpuid_1_edx_x86_features
=
331 F(FPU
) | F(VME
) | F(DE
) | F(PSE
) |
332 F(TSC
) | F(MSR
) | F(PAE
) | F(MCE
) |
333 F(CX8
) | F(APIC
) | 0 /* Reserved */ | F(SEP
) |
334 F(MTRR
) | F(PGE
) | F(MCA
) | F(CMOV
) |
335 F(PAT
) | F(PSE36
) | 0 /* PSN */ | F(CLFLUSH
) |
336 0 /* Reserved, DS, ACPI */ | F(MMX
) |
337 F(FXSR
) | F(XMM
) | F(XMM2
) | F(SELFSNOOP
) |
338 0 /* HTT, TM, Reserved, PBE */;
339 /* cpuid 0x80000001.edx */
340 const u32 kvm_cpuid_8000_0001_edx_x86_features
=
341 F(FPU
) | F(VME
) | F(DE
) | F(PSE
) |
342 F(TSC
) | F(MSR
) | F(PAE
) | F(MCE
) |
343 F(CX8
) | F(APIC
) | 0 /* Reserved */ | F(SYSCALL
) |
344 F(MTRR
) | F(PGE
) | F(MCA
) | F(CMOV
) |
345 F(PAT
) | F(PSE36
) | 0 /* Reserved */ |
346 f_nx
| 0 /* Reserved */ | F(MMXEXT
) | F(MMX
) |
347 F(FXSR
) | F(FXSR_OPT
) | f_gbpages
| f_rdtscp
|
348 0 /* Reserved */ | f_lm
| F(3DNOWEXT
) | F(3DNOW
);
350 const u32 kvm_cpuid_1_ecx_x86_features
=
351 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
352 * but *not* advertised to guests via CPUID ! */
353 F(XMM3
) | F(PCLMULQDQ
) | 0 /* DTES64, MONITOR */ |
354 0 /* DS-CPL, VMX, SMX, EST */ |
355 0 /* TM2 */ | F(SSSE3
) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
356 F(FMA
) | F(CX16
) | 0 /* xTPR Update, PDCM */ |
357 F(PCID
) | 0 /* Reserved, DCA */ | F(XMM4_1
) |
358 F(XMM4_2
) | F(X2APIC
) | F(MOVBE
) | F(POPCNT
) |
359 0 /* Reserved*/ | F(AES
) | F(XSAVE
) | 0 /* OSXSAVE */ | F(AVX
) |
361 /* cpuid 0x80000001.ecx */
362 const u32 kvm_cpuid_8000_0001_ecx_x86_features
=
363 F(LAHF_LM
) | F(CMP_LEGACY
) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
364 F(CR8_LEGACY
) | F(ABM
) | F(SSE4A
) | F(MISALIGNSSE
) |
365 F(3DNOWPREFETCH
) | F(OSVW
) | 0 /* IBS */ | F(XOP
) |
366 0 /* SKINIT, WDT, LWP */ | F(FMA4
) | F(TBM
);
368 /* cpuid 0xC0000001.edx */
369 const u32 kvm_cpuid_C000_0001_edx_x86_features
=
370 F(XSTORE
) | F(XSTORE_EN
) | F(XCRYPT
) | F(XCRYPT_EN
) |
371 F(ACE2
) | F(ACE2_EN
) | F(PHE
) | F(PHE_EN
) |
375 const u32 kvm_cpuid_7_0_ebx_x86_features
=
376 F(FSGSBASE
) | F(BMI1
) | F(HLE
) | F(AVX2
) | F(SMEP
) |
377 F(BMI2
) | F(ERMS
) | f_invpcid
| F(RTM
) | f_mpx
| F(RDSEED
) |
378 F(ADX
) | F(SMAP
) | F(AVX512F
) | F(AVX512PF
) | F(AVX512ER
) |
379 F(AVX512CD
) | F(CLFLUSHOPT
) | F(CLWB
) | F(AVX512DQ
) |
380 F(AVX512BW
) | F(AVX512VL
);
382 /* cpuid 0xD.1.eax */
383 const u32 kvm_cpuid_D_1_eax_x86_features
=
384 F(XSAVEOPT
) | F(XSAVEC
) | F(XGETBV1
) | f_xsaves
;
387 const u32 kvm_cpuid_7_0_ecx_x86_features
= F(PKU
) | 0 /*OSPKE*/;
390 const u32 kvm_cpuid_7_0_edx_x86_features
=
391 KF(AVX512_4VNNIW
) | KF(AVX512_4FMAPS
);
393 /* all calls to cpuid_count() should be made on the same cpu */
398 if (*nent
>= maxnent
)
401 do_cpuid_1_ent(entry
, function
, index
);
406 entry
->eax
= min(entry
->eax
, (u32
)0xd);
409 entry
->edx
&= kvm_cpuid_1_edx_x86_features
;
410 cpuid_mask(&entry
->edx
, CPUID_1_EDX
);
411 entry
->ecx
&= kvm_cpuid_1_ecx_x86_features
;
412 cpuid_mask(&entry
->ecx
, CPUID_1_ECX
);
413 /* we support x2apic emulation even if host does not support
414 * it since we emulate x2apic in software */
415 entry
->ecx
|= F(X2APIC
);
417 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
418 * may return different values. This forces us to get_cpu() before
419 * issuing the first command, and also to emulate this annoying behavior
420 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
422 int t
, times
= entry
->eax
& 0xff;
424 entry
->flags
|= KVM_CPUID_FLAG_STATEFUL_FUNC
;
425 entry
->flags
|= KVM_CPUID_FLAG_STATE_READ_NEXT
;
426 for (t
= 1; t
< times
; ++t
) {
427 if (*nent
>= maxnent
)
430 do_cpuid_1_ent(&entry
[t
], function
, 0);
431 entry
[t
].flags
|= KVM_CPUID_FLAG_STATEFUL_FUNC
;
436 /* function 4 has additional index. */
440 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
441 /* read more entries until cache_type is zero */
443 if (*nent
>= maxnent
)
446 cache_type
= entry
[i
- 1].eax
& 0x1f;
449 do_cpuid_1_ent(&entry
[i
], function
, i
);
451 KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
456 case 6: /* Thermal management */
457 entry
->eax
= 0x4; /* allow ARAT */
463 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
464 /* Mask ebx against host capability word 9 */
466 entry
->ebx
&= kvm_cpuid_7_0_ebx_x86_features
;
467 cpuid_mask(&entry
->ebx
, CPUID_7_0_EBX
);
468 // TSC_ADJUST is emulated
469 entry
->ebx
|= F(TSC_ADJUST
);
470 entry
->ecx
&= kvm_cpuid_7_0_ecx_x86_features
;
471 cpuid_mask(&entry
->ecx
, CPUID_7_ECX
);
472 /* PKU is not yet implemented for shadow paging. */
474 entry
->ecx
&= ~F(PKU
);
475 entry
->edx
&= kvm_cpuid_7_0_edx_x86_features
;
476 entry
->edx
&= get_scattered_cpuid_leaf(7, 0, CPUID_EDX
);
487 case 0xa: { /* Architectural Performance Monitoring */
488 struct x86_pmu_capability cap
;
489 union cpuid10_eax eax
;
490 union cpuid10_edx edx
;
492 perf_get_x86_pmu_capability(&cap
);
495 * Only support guest architectural pmu on a host
496 * with architectural pmu.
499 memset(&cap
, 0, sizeof(cap
));
501 eax
.split
.version_id
= min(cap
.version
, 2);
502 eax
.split
.num_counters
= cap
.num_counters_gp
;
503 eax
.split
.bit_width
= cap
.bit_width_gp
;
504 eax
.split
.mask_length
= cap
.events_mask_len
;
506 edx
.split
.num_counters_fixed
= cap
.num_counters_fixed
;
507 edx
.split
.bit_width_fixed
= cap
.bit_width_fixed
;
508 edx
.split
.reserved
= 0;
510 entry
->eax
= eax
.full
;
511 entry
->ebx
= cap
.events_mask
;
513 entry
->edx
= edx
.full
;
516 /* function 0xb has additional index. */
520 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
521 /* read more entries until level_type is zero */
523 if (*nent
>= maxnent
)
526 level_type
= entry
[i
- 1].ecx
& 0xff00;
529 do_cpuid_1_ent(&entry
[i
], function
, i
);
531 KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
538 u64 supported
= kvm_supported_xcr0();
540 entry
->eax
&= supported
;
541 entry
->ebx
= xstate_required_size(supported
, false);
542 entry
->ecx
= entry
->ebx
;
543 entry
->edx
&= supported
>> 32;
544 entry
->flags
|= KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
548 for (idx
= 1, i
= 1; idx
< 64; ++idx
) {
549 u64 mask
= ((u64
)1 << idx
);
550 if (*nent
>= maxnent
)
553 do_cpuid_1_ent(&entry
[i
], function
, idx
);
555 entry
[i
].eax
&= kvm_cpuid_D_1_eax_x86_features
;
556 cpuid_mask(&entry
[i
].eax
, CPUID_D_1_EAX
);
558 if (entry
[i
].eax
& (F(XSAVES
)|F(XSAVEC
)))
560 xstate_required_size(supported
,
563 if (entry
[i
].eax
== 0 || !(supported
& mask
))
565 if (WARN_ON_ONCE(entry
[i
].ecx
& 1))
571 KVM_CPUID_FLAG_SIGNIFCANT_INDEX
;
577 case KVM_CPUID_SIGNATURE
: {
578 static const char signature
[12] = "KVMKVMKVM\0\0";
579 const u32
*sigptr
= (const u32
*)signature
;
580 entry
->eax
= KVM_CPUID_FEATURES
;
581 entry
->ebx
= sigptr
[0];
582 entry
->ecx
= sigptr
[1];
583 entry
->edx
= sigptr
[2];
586 case KVM_CPUID_FEATURES
:
587 entry
->eax
= (1 << KVM_FEATURE_CLOCKSOURCE
) |
588 (1 << KVM_FEATURE_NOP_IO_DELAY
) |
589 (1 << KVM_FEATURE_CLOCKSOURCE2
) |
590 (1 << KVM_FEATURE_ASYNC_PF
) |
591 (1 << KVM_FEATURE_PV_EOI
) |
592 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT
) |
593 (1 << KVM_FEATURE_PV_UNHALT
);
596 entry
->eax
|= (1 << KVM_FEATURE_STEAL_TIME
);
603 entry
->eax
= min(entry
->eax
, 0x8000001a);
606 entry
->edx
&= kvm_cpuid_8000_0001_edx_x86_features
;
607 cpuid_mask(&entry
->edx
, CPUID_8000_0001_EDX
);
608 entry
->ecx
&= kvm_cpuid_8000_0001_ecx_x86_features
;
609 cpuid_mask(&entry
->ecx
, CPUID_8000_0001_ECX
);
611 case 0x80000007: /* Advanced power management */
612 /* invariant TSC is CPUID.80000007H:EDX[8] */
613 entry
->edx
&= (1 << 8);
614 /* mask against host */
615 entry
->edx
&= boot_cpu_data
.x86_power
;
616 entry
->eax
= entry
->ebx
= entry
->ecx
= 0;
619 unsigned g_phys_as
= (entry
->eax
>> 16) & 0xff;
620 unsigned virt_as
= max((entry
->eax
>> 8) & 0xff, 48U);
621 unsigned phys_as
= entry
->eax
& 0xff;
625 entry
->eax
= g_phys_as
| (virt_as
<< 8);
626 entry
->ebx
= entry
->edx
= 0;
630 entry
->ecx
= entry
->edx
= 0;
636 /*Add support for Centaur's CPUID instruction*/
638 /*Just support up to 0xC0000004 now*/
639 entry
->eax
= min(entry
->eax
, 0xC0000004);
642 entry
->edx
&= kvm_cpuid_C000_0001_edx_x86_features
;
643 cpuid_mask(&entry
->edx
, CPUID_C000_0001_EDX
);
645 case 3: /* Processor serial number */
646 case 5: /* MONITOR/MWAIT */
651 entry
->eax
= entry
->ebx
= entry
->ecx
= entry
->edx
= 0;
655 kvm_x86_ops
->set_supported_cpuid(function
, entry
);
665 static int do_cpuid_ent(struct kvm_cpuid_entry2
*entry
, u32 func
,
666 u32 idx
, int *nent
, int maxnent
, unsigned int type
)
668 if (type
== KVM_GET_EMULATED_CPUID
)
669 return __do_cpuid_ent_emulated(entry
, func
, idx
, nent
, maxnent
);
671 return __do_cpuid_ent(entry
, func
, idx
, nent
, maxnent
);
676 struct kvm_cpuid_param
{
680 bool (*qualifier
)(const struct kvm_cpuid_param
*param
);
683 static bool is_centaur_cpu(const struct kvm_cpuid_param
*param
)
685 return boot_cpu_data
.x86_vendor
== X86_VENDOR_CENTAUR
;
688 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user
*entries
,
689 __u32 num_entries
, unsigned int ioctl_type
)
694 if (ioctl_type
!= KVM_GET_EMULATED_CPUID
)
698 * We want to make sure that ->padding is being passed clean from
699 * userspace in case we want to use it for something in the future.
701 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
702 * have to give ourselves satisfied only with the emulated side. /me
705 for (i
= 0; i
< num_entries
; i
++) {
706 if (copy_from_user(pad
, entries
[i
].padding
, sizeof(pad
)))
709 if (pad
[0] || pad
[1] || pad
[2])
715 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2
*cpuid
,
716 struct kvm_cpuid_entry2 __user
*entries
,
719 struct kvm_cpuid_entry2
*cpuid_entries
;
720 int limit
, nent
= 0, r
= -E2BIG
, i
;
722 static const struct kvm_cpuid_param param
[] = {
723 { .func
= 0, .has_leaf_count
= true },
724 { .func
= 0x80000000, .has_leaf_count
= true },
725 { .func
= 0xC0000000, .qualifier
= is_centaur_cpu
, .has_leaf_count
= true },
726 { .func
= KVM_CPUID_SIGNATURE
},
727 { .func
= KVM_CPUID_FEATURES
},
732 if (cpuid
->nent
> KVM_MAX_CPUID_ENTRIES
)
733 cpuid
->nent
= KVM_MAX_CPUID_ENTRIES
;
735 if (sanity_check_entries(entries
, cpuid
->nent
, type
))
739 cpuid_entries
= vzalloc(sizeof(struct kvm_cpuid_entry2
) * cpuid
->nent
);
744 for (i
= 0; i
< ARRAY_SIZE(param
); i
++) {
745 const struct kvm_cpuid_param
*ent
= ¶m
[i
];
747 if (ent
->qualifier
&& !ent
->qualifier(ent
))
750 r
= do_cpuid_ent(&cpuid_entries
[nent
], ent
->func
, ent
->idx
,
751 &nent
, cpuid
->nent
, type
);
756 if (!ent
->has_leaf_count
)
759 limit
= cpuid_entries
[nent
- 1].eax
;
760 for (func
= ent
->func
+ 1; func
<= limit
&& nent
< cpuid
->nent
&& r
== 0; ++func
)
761 r
= do_cpuid_ent(&cpuid_entries
[nent
], func
, ent
->idx
,
762 &nent
, cpuid
->nent
, type
);
769 if (copy_to_user(entries
, cpuid_entries
,
770 nent
* sizeof(struct kvm_cpuid_entry2
)))
776 vfree(cpuid_entries
);
781 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu
*vcpu
, int i
)
783 struct kvm_cpuid_entry2
*e
= &vcpu
->arch
.cpuid_entries
[i
];
784 int j
, nent
= vcpu
->arch
.cpuid_nent
;
786 e
->flags
&= ~KVM_CPUID_FLAG_STATE_READ_NEXT
;
787 /* when no next entry is found, the current entry[i] is reselected */
788 for (j
= i
+ 1; ; j
= (j
+ 1) % nent
) {
789 struct kvm_cpuid_entry2
*ej
= &vcpu
->arch
.cpuid_entries
[j
];
790 if (ej
->function
== e
->function
) {
791 ej
->flags
|= KVM_CPUID_FLAG_STATE_READ_NEXT
;
795 return 0; /* silence gcc, even though control never reaches here */
798 /* find an entry with matching function, matching index (if needed), and that
799 * should be read next (if it's stateful) */
800 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2
*e
,
801 u32 function
, u32 index
)
803 if (e
->function
!= function
)
805 if ((e
->flags
& KVM_CPUID_FLAG_SIGNIFCANT_INDEX
) && e
->index
!= index
)
807 if ((e
->flags
& KVM_CPUID_FLAG_STATEFUL_FUNC
) &&
808 !(e
->flags
& KVM_CPUID_FLAG_STATE_READ_NEXT
))
813 struct kvm_cpuid_entry2
*kvm_find_cpuid_entry(struct kvm_vcpu
*vcpu
,
814 u32 function
, u32 index
)
817 struct kvm_cpuid_entry2
*best
= NULL
;
819 for (i
= 0; i
< vcpu
->arch
.cpuid_nent
; ++i
) {
820 struct kvm_cpuid_entry2
*e
;
822 e
= &vcpu
->arch
.cpuid_entries
[i
];
823 if (is_matching_cpuid_entry(e
, function
, index
)) {
824 if (e
->flags
& KVM_CPUID_FLAG_STATEFUL_FUNC
)
825 move_to_next_stateful_cpuid_entry(vcpu
, i
);
832 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry
);
835 * If no match is found, check whether we exceed the vCPU's limit
836 * and return the content of the highest valid _standard_ leaf instead.
837 * This is to satisfy the CPUID specification.
839 static struct kvm_cpuid_entry2
* check_cpuid_limit(struct kvm_vcpu
*vcpu
,
840 u32 function
, u32 index
)
842 struct kvm_cpuid_entry2
*maxlevel
;
844 maxlevel
= kvm_find_cpuid_entry(vcpu
, function
& 0x80000000, 0);
845 if (!maxlevel
|| maxlevel
->eax
>= function
)
847 if (function
& 0x80000000) {
848 maxlevel
= kvm_find_cpuid_entry(vcpu
, 0, 0);
852 return kvm_find_cpuid_entry(vcpu
, maxlevel
->eax
, index
);
855 void kvm_cpuid(struct kvm_vcpu
*vcpu
, u32
*eax
, u32
*ebx
, u32
*ecx
, u32
*edx
)
857 u32 function
= *eax
, index
= *ecx
;
858 struct kvm_cpuid_entry2
*best
;
860 best
= kvm_find_cpuid_entry(vcpu
, function
, index
);
863 best
= check_cpuid_limit(vcpu
, function
, index
);
866 * Perfmon not yet supported for L2 guest.
868 if (is_guest_mode(vcpu
) && function
== 0xa)
877 *eax
= *ebx
= *ecx
= *edx
= 0;
878 trace_kvm_cpuid(function
, *eax
, *ebx
, *ecx
, *edx
);
880 EXPORT_SYMBOL_GPL(kvm_cpuid
);
882 int kvm_emulate_cpuid(struct kvm_vcpu
*vcpu
)
884 u32 eax
, ebx
, ecx
, edx
;
886 eax
= kvm_register_read(vcpu
, VCPU_REGS_RAX
);
887 ecx
= kvm_register_read(vcpu
, VCPU_REGS_RCX
);
888 kvm_cpuid(vcpu
, &eax
, &ebx
, &ecx
, &edx
);
889 kvm_register_write(vcpu
, VCPU_REGS_RAX
, eax
);
890 kvm_register_write(vcpu
, VCPU_REGS_RBX
, ebx
);
891 kvm_register_write(vcpu
, VCPU_REGS_RCX
, ecx
);
892 kvm_register_write(vcpu
, VCPU_REGS_RDX
, edx
);
893 kvm_x86_ops
->skip_emulated_instruction(vcpu
);
896 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid
);