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 &= XFEATURE_MASK_EXTEND;
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 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_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);
101 if (vcpu->arch.eager_fpu)
102 kvm_x86_ops->fpu_activate(vcpu);
105 * The existing code assumes virtual address is 48-bit in the canonical
106 * address checks; exit if it is ever changed.
108 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
109 if (best && ((best->eax & 0xff00) >> 8) != 48 &&
110 ((best->eax & 0xff00) >> 8) != 0)
113 /* Update physical-address width */
114 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
116 kvm_pmu_refresh(vcpu);
120 static int is_efer_nx(void)
122 unsigned long long efer = 0;
124 rdmsrl_safe(MSR_EFER, &efer);
125 return efer & EFER_NX;
128 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
131 struct kvm_cpuid_entry2 *e, *entry;
134 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
135 e = &vcpu->arch.cpuid_entries[i];
136 if (e->function == 0x80000001) {
141 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
142 entry->edx &= ~F(NX);
143 printk(KERN_INFO "kvm: guest NX capability removed\n");
147 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
149 struct kvm_cpuid_entry2 *best;
151 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
152 if (!best || best->eax < 0x80000008)
154 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
156 return best->eax & 0xff;
160 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
162 /* when an old userspace process fills a new kernel module */
163 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
164 struct kvm_cpuid *cpuid,
165 struct kvm_cpuid_entry __user *entries)
168 struct kvm_cpuid_entry *cpuid_entries;
171 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
174 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent);
178 if (copy_from_user(cpuid_entries, entries,
179 cpuid->nent * sizeof(struct kvm_cpuid_entry)))
181 for (i = 0; i < cpuid->nent; i++) {
182 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
183 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
184 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
185 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
186 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
187 vcpu->arch.cpuid_entries[i].index = 0;
188 vcpu->arch.cpuid_entries[i].flags = 0;
189 vcpu->arch.cpuid_entries[i].padding[0] = 0;
190 vcpu->arch.cpuid_entries[i].padding[1] = 0;
191 vcpu->arch.cpuid_entries[i].padding[2] = 0;
193 vcpu->arch.cpuid_nent = cpuid->nent;
194 cpuid_fix_nx_cap(vcpu);
195 kvm_apic_set_version(vcpu);
196 kvm_x86_ops->cpuid_update(vcpu);
197 r = kvm_update_cpuid(vcpu);
200 vfree(cpuid_entries);
205 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
206 struct kvm_cpuid2 *cpuid,
207 struct kvm_cpuid_entry2 __user *entries)
212 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
215 if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
216 cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
218 vcpu->arch.cpuid_nent = cpuid->nent;
219 kvm_apic_set_version(vcpu);
220 kvm_x86_ops->cpuid_update(vcpu);
221 r = kvm_update_cpuid(vcpu);
226 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
227 struct kvm_cpuid2 *cpuid,
228 struct kvm_cpuid_entry2 __user *entries)
233 if (cpuid->nent < vcpu->arch.cpuid_nent)
236 if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
237 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
242 cpuid->nent = vcpu->arch.cpuid_nent;
246 static void cpuid_mask(u32 *word, int wordnum)
248 *word &= boot_cpu_data.x86_capability[wordnum];
251 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
254 entry->function = function;
255 entry->index = index;
256 cpuid_count(entry->function, entry->index,
257 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
261 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
262 u32 func, u32 index, int *nent, int maxnent)
266 entry->eax = 1; /* only one leaf currently */
270 entry->ecx = F(MOVBE);
277 entry->function = func;
278 entry->index = index;
283 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
284 u32 index, int *nent, int maxnent)
287 unsigned f_nx = is_efer_nx() ? F(NX) : 0;
289 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
291 unsigned f_lm = F(LM);
293 unsigned f_gbpages = 0;
296 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
297 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
298 unsigned f_mpx = kvm_x86_ops->mpx_supported() ? F(MPX) : 0;
299 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
302 const u32 kvm_supported_word0_x86_features =
303 F(FPU) | F(VME) | F(DE) | F(PSE) |
304 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
305 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
306 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
307 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
308 0 /* Reserved, DS, ACPI */ | F(MMX) |
309 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
310 0 /* HTT, TM, Reserved, PBE */;
311 /* cpuid 0x80000001.edx */
312 const u32 kvm_supported_word1_x86_features =
313 F(FPU) | F(VME) | F(DE) | F(PSE) |
314 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
315 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
316 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
317 F(PAT) | F(PSE36) | 0 /* Reserved */ |
318 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
319 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
320 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
322 const u32 kvm_supported_word4_x86_features =
323 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
324 * but *not* advertised to guests via CPUID ! */
325 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
326 0 /* DS-CPL, VMX, SMX, EST */ |
327 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
328 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
329 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
330 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
331 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
333 /* cpuid 0x80000001.ecx */
334 const u32 kvm_supported_word6_x86_features =
335 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
336 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
337 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
338 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
340 /* cpuid 0xC0000001.edx */
341 const u32 kvm_supported_word5_x86_features =
342 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
343 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
347 const u32 kvm_supported_word9_x86_features =
348 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
349 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
350 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) |
351 F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(PCOMMIT);
353 /* cpuid 0xD.1.eax */
354 const u32 kvm_supported_word10_x86_features =
355 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
357 /* all calls to cpuid_count() should be made on the same cpu */
362 if (*nent >= maxnent)
365 do_cpuid_1_ent(entry, function, index);
370 entry->eax = min(entry->eax, (u32)0xd);
373 entry->edx &= kvm_supported_word0_x86_features;
374 cpuid_mask(&entry->edx, 0);
375 entry->ecx &= kvm_supported_word4_x86_features;
376 cpuid_mask(&entry->ecx, 4);
377 /* we support x2apic emulation even if host does not support
378 * it since we emulate x2apic in software */
379 entry->ecx |= F(X2APIC);
381 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
382 * may return different values. This forces us to get_cpu() before
383 * issuing the first command, and also to emulate this annoying behavior
384 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
386 int t, times = entry->eax & 0xff;
388 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
389 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
390 for (t = 1; t < times; ++t) {
391 if (*nent >= maxnent)
394 do_cpuid_1_ent(&entry[t], function, 0);
395 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
400 /* function 4 has additional index. */
404 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
405 /* read more entries until cache_type is zero */
407 if (*nent >= maxnent)
410 cache_type = entry[i - 1].eax & 0x1f;
413 do_cpuid_1_ent(&entry[i], function, i);
415 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
420 case 6: /* Thermal management */
421 entry->eax = 0x4; /* allow ARAT */
427 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
428 /* Mask ebx against host capability word 9 */
430 entry->ebx &= kvm_supported_word9_x86_features;
431 cpuid_mask(&entry->ebx, 9);
432 // TSC_ADJUST is emulated
433 entry->ebx |= F(TSC_ADJUST);
443 case 0xa: { /* Architectural Performance Monitoring */
444 struct x86_pmu_capability cap;
445 union cpuid10_eax eax;
446 union cpuid10_edx edx;
448 perf_get_x86_pmu_capability(&cap);
451 * Only support guest architectural pmu on a host
452 * with architectural pmu.
455 memset(&cap, 0, sizeof(cap));
457 eax.split.version_id = min(cap.version, 2);
458 eax.split.num_counters = cap.num_counters_gp;
459 eax.split.bit_width = cap.bit_width_gp;
460 eax.split.mask_length = cap.events_mask_len;
462 edx.split.num_counters_fixed = cap.num_counters_fixed;
463 edx.split.bit_width_fixed = cap.bit_width_fixed;
464 edx.split.reserved = 0;
466 entry->eax = eax.full;
467 entry->ebx = cap.events_mask;
469 entry->edx = edx.full;
472 /* function 0xb has additional index. */
476 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
477 /* read more entries until level_type is zero */
479 if (*nent >= maxnent)
482 level_type = entry[i - 1].ecx & 0xff00;
485 do_cpuid_1_ent(&entry[i], function, i);
487 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
494 u64 supported = kvm_supported_xcr0();
496 entry->eax &= supported;
497 entry->ebx = xstate_required_size(supported, false);
498 entry->ecx = entry->ebx;
499 entry->edx &= supported >> 32;
500 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
504 for (idx = 1, i = 1; idx < 64; ++idx) {
505 u64 mask = ((u64)1 << idx);
506 if (*nent >= maxnent)
509 do_cpuid_1_ent(&entry[i], function, idx);
511 entry[i].eax &= kvm_supported_word10_x86_features;
513 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
515 xstate_required_size(supported,
518 if (entry[i].eax == 0 || !(supported & mask))
520 if (WARN_ON_ONCE(entry[i].ecx & 1))
526 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
532 case KVM_CPUID_SIGNATURE: {
533 static const char signature[12] = "KVMKVMKVM\0\0";
534 const u32 *sigptr = (const u32 *)signature;
535 entry->eax = KVM_CPUID_FEATURES;
536 entry->ebx = sigptr[0];
537 entry->ecx = sigptr[1];
538 entry->edx = sigptr[2];
541 case KVM_CPUID_FEATURES:
542 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
543 (1 << KVM_FEATURE_NOP_IO_DELAY) |
544 (1 << KVM_FEATURE_CLOCKSOURCE2) |
545 (1 << KVM_FEATURE_ASYNC_PF) |
546 (1 << KVM_FEATURE_PV_EOI) |
547 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
548 (1 << KVM_FEATURE_PV_UNHALT);
551 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
558 entry->eax = min(entry->eax, 0x8000001a);
561 entry->edx &= kvm_supported_word1_x86_features;
562 cpuid_mask(&entry->edx, 1);
563 entry->ecx &= kvm_supported_word6_x86_features;
564 cpuid_mask(&entry->ecx, 6);
566 case 0x80000007: /* Advanced power management */
567 /* invariant TSC is CPUID.80000007H:EDX[8] */
568 entry->edx &= (1 << 8);
569 /* mask against host */
570 entry->edx &= boot_cpu_data.x86_power;
571 entry->eax = entry->ebx = entry->ecx = 0;
574 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
575 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
576 unsigned phys_as = entry->eax & 0xff;
580 entry->eax = g_phys_as | (virt_as << 8);
581 entry->ebx = entry->edx = 0;
585 entry->ecx = entry->edx = 0;
591 /*Add support for Centaur's CPUID instruction*/
593 /*Just support up to 0xC0000004 now*/
594 entry->eax = min(entry->eax, 0xC0000004);
597 entry->edx &= kvm_supported_word5_x86_features;
598 cpuid_mask(&entry->edx, 5);
600 case 3: /* Processor serial number */
601 case 5: /* MONITOR/MWAIT */
606 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
610 kvm_x86_ops->set_supported_cpuid(function, entry);
620 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
621 u32 idx, int *nent, int maxnent, unsigned int type)
623 if (type == KVM_GET_EMULATED_CPUID)
624 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
626 return __do_cpuid_ent(entry, func, idx, nent, maxnent);
631 struct kvm_cpuid_param {
635 bool (*qualifier)(const struct kvm_cpuid_param *param);
638 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
640 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
643 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
644 __u32 num_entries, unsigned int ioctl_type)
649 if (ioctl_type != KVM_GET_EMULATED_CPUID)
653 * We want to make sure that ->padding is being passed clean from
654 * userspace in case we want to use it for something in the future.
656 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
657 * have to give ourselves satisfied only with the emulated side. /me
660 for (i = 0; i < num_entries; i++) {
661 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
664 if (pad[0] || pad[1] || pad[2])
670 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
671 struct kvm_cpuid_entry2 __user *entries,
674 struct kvm_cpuid_entry2 *cpuid_entries;
675 int limit, nent = 0, r = -E2BIG, i;
677 static const struct kvm_cpuid_param param[] = {
678 { .func = 0, .has_leaf_count = true },
679 { .func = 0x80000000, .has_leaf_count = true },
680 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
681 { .func = KVM_CPUID_SIGNATURE },
682 { .func = KVM_CPUID_FEATURES },
687 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
688 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
690 if (sanity_check_entries(entries, cpuid->nent, type))
694 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
699 for (i = 0; i < ARRAY_SIZE(param); i++) {
700 const struct kvm_cpuid_param *ent = ¶m[i];
702 if (ent->qualifier && !ent->qualifier(ent))
705 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
706 &nent, cpuid->nent, type);
711 if (!ent->has_leaf_count)
714 limit = cpuid_entries[nent - 1].eax;
715 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
716 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
717 &nent, cpuid->nent, type);
724 if (copy_to_user(entries, cpuid_entries,
725 nent * sizeof(struct kvm_cpuid_entry2)))
731 vfree(cpuid_entries);
736 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
738 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
739 int j, nent = vcpu->arch.cpuid_nent;
741 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
742 /* when no next entry is found, the current entry[i] is reselected */
743 for (j = i + 1; ; j = (j + 1) % nent) {
744 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
745 if (ej->function == e->function) {
746 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
750 return 0; /* silence gcc, even though control never reaches here */
753 /* find an entry with matching function, matching index (if needed), and that
754 * should be read next (if it's stateful) */
755 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
756 u32 function, u32 index)
758 if (e->function != function)
760 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
762 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
763 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
768 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
769 u32 function, u32 index)
772 struct kvm_cpuid_entry2 *best = NULL;
774 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
775 struct kvm_cpuid_entry2 *e;
777 e = &vcpu->arch.cpuid_entries[i];
778 if (is_matching_cpuid_entry(e, function, index)) {
779 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
780 move_to_next_stateful_cpuid_entry(vcpu, i);
787 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
790 * If no match is found, check whether we exceed the vCPU's limit
791 * and return the content of the highest valid _standard_ leaf instead.
792 * This is to satisfy the CPUID specification.
794 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
795 u32 function, u32 index)
797 struct kvm_cpuid_entry2 *maxlevel;
799 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
800 if (!maxlevel || maxlevel->eax >= function)
802 if (function & 0x80000000) {
803 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
807 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
810 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
812 u32 function = *eax, index = *ecx;
813 struct kvm_cpuid_entry2 *best;
815 best = kvm_find_cpuid_entry(vcpu, function, index);
818 best = check_cpuid_limit(vcpu, function, index);
821 * Perfmon not yet supported for L2 guest.
823 if (is_guest_mode(vcpu) && function == 0xa)
832 *eax = *ebx = *ecx = *edx = 0;
833 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx);
835 EXPORT_SYMBOL_GPL(kvm_cpuid);
837 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
839 u32 function, eax, ebx, ecx, edx;
841 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
842 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
843 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx);
844 kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
845 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
846 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
847 kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
848 kvm_x86_ops->skip_emulated_instruction(vcpu);
850 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);