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>
19 #include <asm/fpu/internal.h> /* For use_eager_fpu. Ugh! */
21 #include <asm/fpu/xstate.h>
28 static u32 xstate_required_size(u64 xstate_bv, bool compacted)
31 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
33 xstate_bv &= XSTATE_EXTEND_MASK;
35 if (xstate_bv & 0x1) {
36 u32 eax, ebx, ecx, edx, offset;
37 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
38 offset = compacted ? ret : ebx;
39 ret = max(ret, offset + eax);
49 u64 kvm_supported_xcr0(void)
51 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
53 if (!kvm_x86_ops->mpx_supported())
54 xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR);
59 #define F(x) bit(X86_FEATURE_##x)
61 int kvm_update_cpuid(struct kvm_vcpu *vcpu)
63 struct kvm_cpuid_entry2 *best;
64 struct kvm_lapic *apic = vcpu->arch.apic;
66 best = kvm_find_cpuid_entry(vcpu, 1, 0);
70 /* Update OSXSAVE bit */
71 if (cpu_has_xsave && best->function == 0x1) {
72 best->ecx &= ~F(OSXSAVE);
73 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
74 best->ecx |= F(OSXSAVE);
78 if (best->ecx & F(TSC_DEADLINE_TIMER))
79 apic->lapic_timer.timer_mode_mask = 3 << 17;
81 apic->lapic_timer.timer_mode_mask = 1 << 17;
84 best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
86 vcpu->arch.guest_supported_xcr0 = 0;
87 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
89 vcpu->arch.guest_supported_xcr0 =
90 (best->eax | ((u64)best->edx << 32)) &
92 vcpu->arch.guest_xstate_size = best->ebx =
93 xstate_required_size(vcpu->arch.xcr0, false);
96 best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
97 if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
98 best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
100 vcpu->arch.eager_fpu = use_eager_fpu() || guest_cpuid_has_mpx(vcpu);
103 * The existing code assumes virtual address is 48-bit in the canonical
104 * address checks; exit if it is ever changed.
106 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
107 if (best && ((best->eax & 0xff00) >> 8) != 48 &&
108 ((best->eax & 0xff00) >> 8) != 0)
111 /* Update physical-address width */
112 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
114 kvm_pmu_refresh(vcpu);
118 static int is_efer_nx(void)
120 unsigned long long efer = 0;
122 rdmsrl_safe(MSR_EFER, &efer);
123 return efer & EFER_NX;
126 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
129 struct kvm_cpuid_entry2 *e, *entry;
132 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
133 e = &vcpu->arch.cpuid_entries[i];
134 if (e->function == 0x80000001) {
139 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
140 entry->edx &= ~F(NX);
141 printk(KERN_INFO "kvm: guest NX capability removed\n");
145 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
147 struct kvm_cpuid_entry2 *best;
149 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
150 if (!best || best->eax < 0x80000008)
152 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
154 return best->eax & 0xff;
158 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
160 /* when an old userspace process fills a new kernel module */
161 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
162 struct kvm_cpuid *cpuid,
163 struct kvm_cpuid_entry __user *entries)
166 struct kvm_cpuid_entry *cpuid_entries;
169 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
172 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent);
176 if (copy_from_user(cpuid_entries, entries,
177 cpuid->nent * sizeof(struct kvm_cpuid_entry)))
179 for (i = 0; i < cpuid->nent; i++) {
180 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
181 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
182 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
183 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
184 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
185 vcpu->arch.cpuid_entries[i].index = 0;
186 vcpu->arch.cpuid_entries[i].flags = 0;
187 vcpu->arch.cpuid_entries[i].padding[0] = 0;
188 vcpu->arch.cpuid_entries[i].padding[1] = 0;
189 vcpu->arch.cpuid_entries[i].padding[2] = 0;
191 vcpu->arch.cpuid_nent = cpuid->nent;
192 cpuid_fix_nx_cap(vcpu);
193 kvm_apic_set_version(vcpu);
194 kvm_x86_ops->cpuid_update(vcpu);
195 r = kvm_update_cpuid(vcpu);
198 vfree(cpuid_entries);
203 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
204 struct kvm_cpuid2 *cpuid,
205 struct kvm_cpuid_entry2 __user *entries)
210 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
213 if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
214 cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
216 vcpu->arch.cpuid_nent = cpuid->nent;
217 kvm_apic_set_version(vcpu);
218 kvm_x86_ops->cpuid_update(vcpu);
219 r = kvm_update_cpuid(vcpu);
224 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
225 struct kvm_cpuid2 *cpuid,
226 struct kvm_cpuid_entry2 __user *entries)
231 if (cpuid->nent < vcpu->arch.cpuid_nent)
234 if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
235 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
240 cpuid->nent = vcpu->arch.cpuid_nent;
244 static void cpuid_mask(u32 *word, int wordnum)
246 *word &= boot_cpu_data.x86_capability[wordnum];
249 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
252 entry->function = function;
253 entry->index = index;
254 cpuid_count(entry->function, entry->index,
255 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
259 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
260 u32 func, u32 index, int *nent, int maxnent)
264 entry->eax = 1; /* only one leaf currently */
268 entry->ecx = F(MOVBE);
275 entry->function = func;
276 entry->index = index;
281 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
282 u32 index, int *nent, int maxnent)
285 unsigned f_nx = is_efer_nx() ? F(NX) : 0;
287 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
289 unsigned f_lm = F(LM);
291 unsigned f_gbpages = 0;
294 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
295 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
296 unsigned f_mpx = kvm_x86_ops->mpx_supported() ? F(MPX) : 0;
297 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
300 const u32 kvm_supported_word0_x86_features =
301 F(FPU) | F(VME) | F(DE) | F(PSE) |
302 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
303 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
304 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
305 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
306 0 /* Reserved, DS, ACPI */ | F(MMX) |
307 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
308 0 /* HTT, TM, Reserved, PBE */;
309 /* cpuid 0x80000001.edx */
310 const u32 kvm_supported_word1_x86_features =
311 F(FPU) | F(VME) | F(DE) | F(PSE) |
312 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
313 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
314 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
315 F(PAT) | F(PSE36) | 0 /* Reserved */ |
316 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
317 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
318 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
320 const u32 kvm_supported_word4_x86_features =
321 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
322 * but *not* advertised to guests via CPUID ! */
323 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
324 0 /* DS-CPL, VMX, SMX, EST */ |
325 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
326 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
327 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
328 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
329 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
331 /* cpuid 0x80000001.ecx */
332 const u32 kvm_supported_word6_x86_features =
333 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
334 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
335 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
336 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
338 /* cpuid 0xC0000001.edx */
339 const u32 kvm_supported_word5_x86_features =
340 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
341 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
345 const u32 kvm_supported_word9_x86_features =
346 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
347 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
348 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) |
351 /* cpuid 0xD.1.eax */
352 const u32 kvm_supported_word10_x86_features =
353 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
355 /* all calls to cpuid_count() should be made on the same cpu */
360 if (*nent >= maxnent)
363 do_cpuid_1_ent(entry, function, index);
368 entry->eax = min(entry->eax, (u32)0xd);
371 entry->edx &= kvm_supported_word0_x86_features;
372 cpuid_mask(&entry->edx, 0);
373 entry->ecx &= kvm_supported_word4_x86_features;
374 cpuid_mask(&entry->ecx, 4);
375 /* we support x2apic emulation even if host does not support
376 * it since we emulate x2apic in software */
377 entry->ecx |= F(X2APIC);
379 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
380 * may return different values. This forces us to get_cpu() before
381 * issuing the first command, and also to emulate this annoying behavior
382 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
384 int t, times = entry->eax & 0xff;
386 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
387 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
388 for (t = 1; t < times; ++t) {
389 if (*nent >= maxnent)
392 do_cpuid_1_ent(&entry[t], function, 0);
393 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
398 /* function 4 has additional index. */
402 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
403 /* read more entries until cache_type is zero */
405 if (*nent >= maxnent)
408 cache_type = entry[i - 1].eax & 0x1f;
411 do_cpuid_1_ent(&entry[i], function, i);
413 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
418 case 6: /* Thermal management */
419 entry->eax = 0x4; /* allow ARAT */
425 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
426 /* Mask ebx against host capability word 9 */
428 entry->ebx &= kvm_supported_word9_x86_features;
429 cpuid_mask(&entry->ebx, 9);
430 // TSC_ADJUST is emulated
431 entry->ebx |= F(TSC_ADJUST);
441 case 0xa: { /* Architectural Performance Monitoring */
442 struct x86_pmu_capability cap;
443 union cpuid10_eax eax;
444 union cpuid10_edx edx;
446 perf_get_x86_pmu_capability(&cap);
449 * Only support guest architectural pmu on a host
450 * with architectural pmu.
453 memset(&cap, 0, sizeof(cap));
455 eax.split.version_id = min(cap.version, 2);
456 eax.split.num_counters = cap.num_counters_gp;
457 eax.split.bit_width = cap.bit_width_gp;
458 eax.split.mask_length = cap.events_mask_len;
460 edx.split.num_counters_fixed = cap.num_counters_fixed;
461 edx.split.bit_width_fixed = cap.bit_width_fixed;
462 edx.split.reserved = 0;
464 entry->eax = eax.full;
465 entry->ebx = cap.events_mask;
467 entry->edx = edx.full;
470 /* function 0xb has additional index. */
474 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
475 /* read more entries until level_type is zero */
477 if (*nent >= maxnent)
480 level_type = entry[i - 1].ecx & 0xff00;
483 do_cpuid_1_ent(&entry[i], function, i);
485 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
492 u64 supported = kvm_supported_xcr0();
494 entry->eax &= supported;
495 entry->ebx = xstate_required_size(supported, false);
496 entry->ecx = entry->ebx;
497 entry->edx &= supported >> 32;
498 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
502 for (idx = 1, i = 1; idx < 64; ++idx) {
503 u64 mask = ((u64)1 << idx);
504 if (*nent >= maxnent)
507 do_cpuid_1_ent(&entry[i], function, idx);
509 entry[i].eax &= kvm_supported_word10_x86_features;
511 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
513 xstate_required_size(supported,
516 if (entry[i].eax == 0 || !(supported & mask))
518 if (WARN_ON_ONCE(entry[i].ecx & 1))
524 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
530 case KVM_CPUID_SIGNATURE: {
531 static const char signature[12] = "KVMKVMKVM\0\0";
532 const u32 *sigptr = (const u32 *)signature;
533 entry->eax = KVM_CPUID_FEATURES;
534 entry->ebx = sigptr[0];
535 entry->ecx = sigptr[1];
536 entry->edx = sigptr[2];
539 case KVM_CPUID_FEATURES:
540 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
541 (1 << KVM_FEATURE_NOP_IO_DELAY) |
542 (1 << KVM_FEATURE_CLOCKSOURCE2) |
543 (1 << KVM_FEATURE_ASYNC_PF) |
544 (1 << KVM_FEATURE_PV_EOI) |
545 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
546 (1 << KVM_FEATURE_PV_UNHALT);
549 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
556 entry->eax = min(entry->eax, 0x8000001a);
559 entry->edx &= kvm_supported_word1_x86_features;
560 cpuid_mask(&entry->edx, 1);
561 entry->ecx &= kvm_supported_word6_x86_features;
562 cpuid_mask(&entry->ecx, 6);
564 case 0x80000007: /* Advanced power management */
565 /* invariant TSC is CPUID.80000007H:EDX[8] */
566 entry->edx &= (1 << 8);
567 /* mask against host */
568 entry->edx &= boot_cpu_data.x86_power;
569 entry->eax = entry->ebx = entry->ecx = 0;
572 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
573 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
574 unsigned phys_as = entry->eax & 0xff;
578 entry->eax = g_phys_as | (virt_as << 8);
579 entry->ebx = entry->edx = 0;
583 entry->ecx = entry->edx = 0;
589 /*Add support for Centaur's CPUID instruction*/
591 /*Just support up to 0xC0000004 now*/
592 entry->eax = min(entry->eax, 0xC0000004);
595 entry->edx &= kvm_supported_word5_x86_features;
596 cpuid_mask(&entry->edx, 5);
598 case 3: /* Processor serial number */
599 case 5: /* MONITOR/MWAIT */
604 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
608 kvm_x86_ops->set_supported_cpuid(function, entry);
618 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
619 u32 idx, int *nent, int maxnent, unsigned int type)
621 if (type == KVM_GET_EMULATED_CPUID)
622 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
624 return __do_cpuid_ent(entry, func, idx, nent, maxnent);
629 struct kvm_cpuid_param {
633 bool (*qualifier)(const struct kvm_cpuid_param *param);
636 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
638 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
641 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
642 __u32 num_entries, unsigned int ioctl_type)
647 if (ioctl_type != KVM_GET_EMULATED_CPUID)
651 * We want to make sure that ->padding is being passed clean from
652 * userspace in case we want to use it for something in the future.
654 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
655 * have to give ourselves satisfied only with the emulated side. /me
658 for (i = 0; i < num_entries; i++) {
659 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
662 if (pad[0] || pad[1] || pad[2])
668 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
669 struct kvm_cpuid_entry2 __user *entries,
672 struct kvm_cpuid_entry2 *cpuid_entries;
673 int limit, nent = 0, r = -E2BIG, i;
675 static const struct kvm_cpuid_param param[] = {
676 { .func = 0, .has_leaf_count = true },
677 { .func = 0x80000000, .has_leaf_count = true },
678 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
679 { .func = KVM_CPUID_SIGNATURE },
680 { .func = KVM_CPUID_FEATURES },
685 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
686 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
688 if (sanity_check_entries(entries, cpuid->nent, type))
692 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
697 for (i = 0; i < ARRAY_SIZE(param); i++) {
698 const struct kvm_cpuid_param *ent = ¶m[i];
700 if (ent->qualifier && !ent->qualifier(ent))
703 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
704 &nent, cpuid->nent, type);
709 if (!ent->has_leaf_count)
712 limit = cpuid_entries[nent - 1].eax;
713 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
714 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
715 &nent, cpuid->nent, type);
722 if (copy_to_user(entries, cpuid_entries,
723 nent * sizeof(struct kvm_cpuid_entry2)))
729 vfree(cpuid_entries);
734 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
736 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
737 int j, nent = vcpu->arch.cpuid_nent;
739 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
740 /* when no next entry is found, the current entry[i] is reselected */
741 for (j = i + 1; ; j = (j + 1) % nent) {
742 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
743 if (ej->function == e->function) {
744 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
748 return 0; /* silence gcc, even though control never reaches here */
751 /* find an entry with matching function, matching index (if needed), and that
752 * should be read next (if it's stateful) */
753 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
754 u32 function, u32 index)
756 if (e->function != function)
758 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
760 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
761 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
766 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
767 u32 function, u32 index)
770 struct kvm_cpuid_entry2 *best = NULL;
772 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
773 struct kvm_cpuid_entry2 *e;
775 e = &vcpu->arch.cpuid_entries[i];
776 if (is_matching_cpuid_entry(e, function, index)) {
777 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
778 move_to_next_stateful_cpuid_entry(vcpu, i);
785 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
788 * If no match is found, check whether we exceed the vCPU's limit
789 * and return the content of the highest valid _standard_ leaf instead.
790 * This is to satisfy the CPUID specification.
792 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
793 u32 function, u32 index)
795 struct kvm_cpuid_entry2 *maxlevel;
797 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
798 if (!maxlevel || maxlevel->eax >= function)
800 if (function & 0x80000000) {
801 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
805 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
808 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
810 u32 function = *eax, index = *ecx;
811 struct kvm_cpuid_entry2 *best;
813 best = kvm_find_cpuid_entry(vcpu, function, index);
816 best = check_cpuid_limit(vcpu, function, index);
819 * Perfmon not yet supported for L2 guest.
821 if (is_guest_mode(vcpu) && function == 0xa)
830 *eax = *ebx = *ecx = *edx = 0;
831 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx);
833 EXPORT_SYMBOL_GPL(kvm_cpuid);
835 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
837 u32 function, eax, ebx, ecx, edx;
839 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
840 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
841 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx);
842 kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
843 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
844 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
845 kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
846 kvm_x86_ops->skip_emulated_instruction(vcpu);
848 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);