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 <linux/sched/stat.h>
21 #include <asm/processor.h>
23 #include <asm/fpu/xstate.h>
30 static u32 xstate_required_size(u64 xstate_bv, bool compacted)
33 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
35 xstate_bv &= XFEATURE_MASK_EXTEND;
37 if (xstate_bv & 0x1) {
38 u32 eax, ebx, ecx, edx, offset;
39 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
40 offset = compacted ? ret : ebx;
41 ret = max(ret, offset + eax);
51 bool kvm_mpx_supported(void)
53 return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR))
54 && kvm_x86_ops->mpx_supported());
56 EXPORT_SYMBOL_GPL(kvm_mpx_supported);
58 u64 kvm_supported_xcr0(void)
60 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
62 if (!kvm_mpx_supported())
63 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
68 #define F(x) bit(X86_FEATURE_##x)
70 /* For scattered features from cpufeatures.h; we currently expose none */
71 #define KF(x) bit(KVM_CPUID_BIT_##x)
73 int kvm_update_cpuid(struct kvm_vcpu *vcpu)
75 struct kvm_cpuid_entry2 *best;
76 struct kvm_lapic *apic = vcpu->arch.apic;
78 best = kvm_find_cpuid_entry(vcpu, 1, 0);
82 /* Update OSXSAVE bit */
83 if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) {
84 best->ecx &= ~F(OSXSAVE);
85 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
86 best->ecx |= F(OSXSAVE);
89 best->edx &= ~F(APIC);
90 if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE)
94 if (best->ecx & F(TSC_DEADLINE_TIMER))
95 apic->lapic_timer.timer_mode_mask = 3 << 17;
97 apic->lapic_timer.timer_mode_mask = 1 << 17;
100 best = kvm_find_cpuid_entry(vcpu, 7, 0);
102 /* Update OSPKE bit */
103 if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) {
104 best->ecx &= ~F(OSPKE);
105 if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE))
106 best->ecx |= F(OSPKE);
110 best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
112 vcpu->arch.guest_supported_xcr0 = 0;
113 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
115 vcpu->arch.guest_supported_xcr0 =
116 (best->eax | ((u64)best->edx << 32)) &
117 kvm_supported_xcr0();
118 vcpu->arch.guest_xstate_size = best->ebx =
119 xstate_required_size(vcpu->arch.xcr0, false);
122 best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
123 if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
124 best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
127 * The existing code assumes virtual address is 48-bit or 57-bit in the
128 * canonical address checks; exit if it is ever changed.
130 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
132 int vaddr_bits = (best->eax & 0xff00) >> 8;
134 if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
138 best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0);
139 if (kvm_hlt_in_guest(vcpu->kvm) && best &&
140 (best->eax & (1 << KVM_FEATURE_PV_UNHALT)))
141 best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT);
143 /* Update physical-address width */
144 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
145 kvm_mmu_reset_context(vcpu);
147 kvm_pmu_refresh(vcpu);
151 static int is_efer_nx(void)
153 unsigned long long efer = 0;
155 rdmsrl_safe(MSR_EFER, &efer);
156 return efer & EFER_NX;
159 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
162 struct kvm_cpuid_entry2 *e, *entry;
165 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
166 e = &vcpu->arch.cpuid_entries[i];
167 if (e->function == 0x80000001) {
172 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
173 entry->edx &= ~F(NX);
174 printk(KERN_INFO "kvm: guest NX capability removed\n");
178 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
180 struct kvm_cpuid_entry2 *best;
182 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
183 if (!best || best->eax < 0x80000008)
185 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
187 return best->eax & 0xff;
191 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
193 /* when an old userspace process fills a new kernel module */
194 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
195 struct kvm_cpuid *cpuid,
196 struct kvm_cpuid_entry __user *entries)
199 struct kvm_cpuid_entry *cpuid_entries = NULL;
202 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
206 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) *
211 if (copy_from_user(cpuid_entries, entries,
212 cpuid->nent * sizeof(struct kvm_cpuid_entry)))
215 for (i = 0; i < cpuid->nent; i++) {
216 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
217 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
218 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
219 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
220 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
221 vcpu->arch.cpuid_entries[i].index = 0;
222 vcpu->arch.cpuid_entries[i].flags = 0;
223 vcpu->arch.cpuid_entries[i].padding[0] = 0;
224 vcpu->arch.cpuid_entries[i].padding[1] = 0;
225 vcpu->arch.cpuid_entries[i].padding[2] = 0;
227 vcpu->arch.cpuid_nent = cpuid->nent;
228 cpuid_fix_nx_cap(vcpu);
229 kvm_apic_set_version(vcpu);
230 kvm_x86_ops->cpuid_update(vcpu);
231 r = kvm_update_cpuid(vcpu);
234 vfree(cpuid_entries);
238 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
239 struct kvm_cpuid2 *cpuid,
240 struct kvm_cpuid_entry2 __user *entries)
245 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
248 if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
249 cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
251 vcpu->arch.cpuid_nent = cpuid->nent;
252 kvm_apic_set_version(vcpu);
253 kvm_x86_ops->cpuid_update(vcpu);
254 r = kvm_update_cpuid(vcpu);
259 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
260 struct kvm_cpuid2 *cpuid,
261 struct kvm_cpuid_entry2 __user *entries)
266 if (cpuid->nent < vcpu->arch.cpuid_nent)
269 if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
270 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
275 cpuid->nent = vcpu->arch.cpuid_nent;
279 static void cpuid_mask(u32 *word, int wordnum)
281 *word &= boot_cpu_data.x86_capability[wordnum];
284 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
287 entry->function = function;
288 entry->index = index;
289 cpuid_count(entry->function, entry->index,
290 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
294 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
295 u32 func, u32 index, int *nent, int maxnent)
303 entry->ecx = F(MOVBE);
307 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
309 entry->ecx = F(RDPID);
315 entry->function = func;
316 entry->index = index;
321 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
322 u32 index, int *nent, int maxnent)
325 unsigned f_nx = is_efer_nx() ? F(NX) : 0;
327 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
329 unsigned f_lm = F(LM);
331 unsigned f_gbpages = 0;
334 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
335 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
336 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
337 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
338 unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0;
341 const u32 kvm_cpuid_1_edx_x86_features =
342 F(FPU) | F(VME) | F(DE) | F(PSE) |
343 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
344 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
345 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
346 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
347 0 /* Reserved, DS, ACPI */ | F(MMX) |
348 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
349 0 /* HTT, TM, Reserved, PBE */;
350 /* cpuid 0x80000001.edx */
351 const u32 kvm_cpuid_8000_0001_edx_x86_features =
352 F(FPU) | F(VME) | F(DE) | F(PSE) |
353 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
354 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
355 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
356 F(PAT) | F(PSE36) | 0 /* Reserved */ |
357 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
358 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
359 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
361 const u32 kvm_cpuid_1_ecx_x86_features =
362 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
363 * but *not* advertised to guests via CPUID ! */
364 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
365 0 /* DS-CPL, VMX, SMX, EST */ |
366 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
367 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
368 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
369 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
370 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
372 /* cpuid 0x80000001.ecx */
373 const u32 kvm_cpuid_8000_0001_ecx_x86_features =
374 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
375 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
376 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
377 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) |
378 F(TOPOEXT) | F(PERFCTR_CORE);
380 /* cpuid 0x80000008.ebx */
381 const u32 kvm_cpuid_8000_0008_ebx_x86_features =
382 F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
385 /* cpuid 0xC0000001.edx */
386 const u32 kvm_cpuid_C000_0001_edx_x86_features =
387 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
388 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
392 const u32 kvm_cpuid_7_0_ebx_x86_features =
393 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
394 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
395 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
396 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) |
397 F(SHA_NI) | F(AVX512BW) | F(AVX512VL);
399 /* cpuid 0xD.1.eax */
400 const u32 kvm_cpuid_D_1_eax_x86_features =
401 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
404 const u32 kvm_cpuid_7_0_ecx_x86_features =
405 F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ |
406 F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) |
407 F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG);
410 const u32 kvm_cpuid_7_0_edx_x86_features =
411 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
412 F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES);
414 /* all calls to cpuid_count() should be made on the same cpu */
419 if (*nent >= maxnent)
422 do_cpuid_1_ent(entry, function, index);
427 entry->eax = min(entry->eax, (u32)0xd);
430 entry->edx &= kvm_cpuid_1_edx_x86_features;
431 cpuid_mask(&entry->edx, CPUID_1_EDX);
432 entry->ecx &= kvm_cpuid_1_ecx_x86_features;
433 cpuid_mask(&entry->ecx, CPUID_1_ECX);
434 /* we support x2apic emulation even if host does not support
435 * it since we emulate x2apic in software */
436 entry->ecx |= F(X2APIC);
438 /* function 2 entries are STATEFUL. That is, repeated cpuid commands
439 * may return different values. This forces us to get_cpu() before
440 * issuing the first command, and also to emulate this annoying behavior
441 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
443 int t, times = entry->eax & 0xff;
445 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
446 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
447 for (t = 1; t < times; ++t) {
448 if (*nent >= maxnent)
451 do_cpuid_1_ent(&entry[t], function, 0);
452 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
457 /* function 4 has additional index. */
461 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
462 /* read more entries until cache_type is zero */
464 if (*nent >= maxnent)
467 cache_type = entry[i - 1].eax & 0x1f;
470 do_cpuid_1_ent(&entry[i], function, i);
472 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
477 case 6: /* Thermal management */
478 entry->eax = 0x4; /* allow ARAT */
484 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
485 /* Mask ebx against host capability word 9 */
487 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features;
488 cpuid_mask(&entry->ebx, CPUID_7_0_EBX);
489 // TSC_ADJUST is emulated
490 entry->ebx |= F(TSC_ADJUST);
491 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
492 cpuid_mask(&entry->ecx, CPUID_7_ECX);
493 entry->ecx |= f_umip;
494 /* PKU is not yet implemented for shadow paging. */
495 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
496 entry->ecx &= ~F(PKU);
497 entry->edx &= kvm_cpuid_7_0_edx_x86_features;
498 cpuid_mask(&entry->edx, CPUID_7_EDX);
500 * We emulate ARCH_CAPABILITIES in software even
501 * if the host doesn't support it.
503 entry->edx |= F(ARCH_CAPABILITIES);
514 case 0xa: { /* Architectural Performance Monitoring */
515 struct x86_pmu_capability cap;
516 union cpuid10_eax eax;
517 union cpuid10_edx edx;
519 perf_get_x86_pmu_capability(&cap);
522 * Only support guest architectural pmu on a host
523 * with architectural pmu.
526 memset(&cap, 0, sizeof(cap));
528 eax.split.version_id = min(cap.version, 2);
529 eax.split.num_counters = cap.num_counters_gp;
530 eax.split.bit_width = cap.bit_width_gp;
531 eax.split.mask_length = cap.events_mask_len;
533 edx.split.num_counters_fixed = cap.num_counters_fixed;
534 edx.split.bit_width_fixed = cap.bit_width_fixed;
535 edx.split.reserved = 0;
537 entry->eax = eax.full;
538 entry->ebx = cap.events_mask;
540 entry->edx = edx.full;
543 /* function 0xb has additional index. */
547 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
548 /* read more entries until level_type is zero */
550 if (*nent >= maxnent)
553 level_type = entry[i - 1].ecx & 0xff00;
556 do_cpuid_1_ent(&entry[i], function, i);
558 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
565 u64 supported = kvm_supported_xcr0();
567 entry->eax &= supported;
568 entry->ebx = xstate_required_size(supported, false);
569 entry->ecx = entry->ebx;
570 entry->edx &= supported >> 32;
571 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
575 for (idx = 1, i = 1; idx < 64; ++idx) {
576 u64 mask = ((u64)1 << idx);
577 if (*nent >= maxnent)
580 do_cpuid_1_ent(&entry[i], function, idx);
582 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
583 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
585 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
587 xstate_required_size(supported,
590 if (entry[i].eax == 0 || !(supported & mask))
592 if (WARN_ON_ONCE(entry[i].ecx & 1))
598 KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
604 case KVM_CPUID_SIGNATURE: {
605 static const char signature[12] = "KVMKVMKVM\0\0";
606 const u32 *sigptr = (const u32 *)signature;
607 entry->eax = KVM_CPUID_FEATURES;
608 entry->ebx = sigptr[0];
609 entry->ecx = sigptr[1];
610 entry->edx = sigptr[2];
613 case KVM_CPUID_FEATURES:
614 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
615 (1 << KVM_FEATURE_NOP_IO_DELAY) |
616 (1 << KVM_FEATURE_CLOCKSOURCE2) |
617 (1 << KVM_FEATURE_ASYNC_PF) |
618 (1 << KVM_FEATURE_PV_EOI) |
619 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
620 (1 << KVM_FEATURE_PV_UNHALT) |
621 (1 << KVM_FEATURE_PV_TLB_FLUSH) |
622 (1 << KVM_FEATURE_ASYNC_PF_VMEXIT);
625 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
632 entry->eax = min(entry->eax, 0x8000001f);
635 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features;
636 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX);
637 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features;
638 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX);
640 case 0x80000007: /* Advanced power management */
641 /* invariant TSC is CPUID.80000007H:EDX[8] */
642 entry->edx &= (1 << 8);
643 /* mask against host */
644 entry->edx &= boot_cpu_data.x86_power;
645 entry->eax = entry->ebx = entry->ecx = 0;
648 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
649 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
650 unsigned phys_as = entry->eax & 0xff;
654 entry->eax = g_phys_as | (virt_as << 8);
657 * IBRS, IBPB and VIRT_SSBD aren't necessarily present in
660 if (boot_cpu_has(X86_FEATURE_AMD_IBPB))
661 entry->ebx |= F(AMD_IBPB);
662 if (boot_cpu_has(X86_FEATURE_AMD_IBRS))
663 entry->ebx |= F(AMD_IBRS);
664 if (boot_cpu_has(X86_FEATURE_VIRT_SSBD))
665 entry->ebx |= F(VIRT_SSBD);
666 entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
667 cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
669 * The preference is to use SPEC CTRL MSR instead of the
672 if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) &&
673 !boot_cpu_has(X86_FEATURE_AMD_SSBD))
674 entry->ebx |= F(VIRT_SSBD);
678 entry->ecx = entry->edx = 0;
684 /*Add support for Centaur's CPUID instruction*/
686 /*Just support up to 0xC0000004 now*/
687 entry->eax = min(entry->eax, 0xC0000004);
690 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features;
691 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX);
693 case 3: /* Processor serial number */
694 case 5: /* MONITOR/MWAIT */
699 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
703 kvm_x86_ops->set_supported_cpuid(function, entry);
713 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
714 u32 idx, int *nent, int maxnent, unsigned int type)
716 if (type == KVM_GET_EMULATED_CPUID)
717 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
719 return __do_cpuid_ent(entry, func, idx, nent, maxnent);
724 struct kvm_cpuid_param {
728 bool (*qualifier)(const struct kvm_cpuid_param *param);
731 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
733 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
736 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
737 __u32 num_entries, unsigned int ioctl_type)
742 if (ioctl_type != KVM_GET_EMULATED_CPUID)
746 * We want to make sure that ->padding is being passed clean from
747 * userspace in case we want to use it for something in the future.
749 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
750 * have to give ourselves satisfied only with the emulated side. /me
753 for (i = 0; i < num_entries; i++) {
754 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
757 if (pad[0] || pad[1] || pad[2])
763 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
764 struct kvm_cpuid_entry2 __user *entries,
767 struct kvm_cpuid_entry2 *cpuid_entries;
768 int limit, nent = 0, r = -E2BIG, i;
770 static const struct kvm_cpuid_param param[] = {
771 { .func = 0, .has_leaf_count = true },
772 { .func = 0x80000000, .has_leaf_count = true },
773 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
774 { .func = KVM_CPUID_SIGNATURE },
775 { .func = KVM_CPUID_FEATURES },
780 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
781 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
783 if (sanity_check_entries(entries, cpuid->nent, type))
787 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
792 for (i = 0; i < ARRAY_SIZE(param); i++) {
793 const struct kvm_cpuid_param *ent = ¶m[i];
795 if (ent->qualifier && !ent->qualifier(ent))
798 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
799 &nent, cpuid->nent, type);
804 if (!ent->has_leaf_count)
807 limit = cpuid_entries[nent - 1].eax;
808 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
809 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
810 &nent, cpuid->nent, type);
817 if (copy_to_user(entries, cpuid_entries,
818 nent * sizeof(struct kvm_cpuid_entry2)))
824 vfree(cpuid_entries);
829 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
831 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
832 struct kvm_cpuid_entry2 *ej;
834 int nent = vcpu->arch.cpuid_nent;
836 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
837 /* when no next entry is found, the current entry[i] is reselected */
840 ej = &vcpu->arch.cpuid_entries[j];
841 } while (ej->function != e->function);
843 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
848 /* find an entry with matching function, matching index (if needed), and that
849 * should be read next (if it's stateful) */
850 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
851 u32 function, u32 index)
853 if (e->function != function)
855 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
857 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
858 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
863 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
864 u32 function, u32 index)
867 struct kvm_cpuid_entry2 *best = NULL;
869 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
870 struct kvm_cpuid_entry2 *e;
872 e = &vcpu->arch.cpuid_entries[i];
873 if (is_matching_cpuid_entry(e, function, index)) {
874 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
875 move_to_next_stateful_cpuid_entry(vcpu, i);
882 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
885 * If no match is found, check whether we exceed the vCPU's limit
886 * and return the content of the highest valid _standard_ leaf instead.
887 * This is to satisfy the CPUID specification.
889 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
890 u32 function, u32 index)
892 struct kvm_cpuid_entry2 *maxlevel;
894 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
895 if (!maxlevel || maxlevel->eax >= function)
897 if (function & 0x80000000) {
898 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
902 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
905 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
906 u32 *ecx, u32 *edx, bool check_limit)
908 u32 function = *eax, index = *ecx;
909 struct kvm_cpuid_entry2 *best;
910 bool entry_found = true;
912 best = kvm_find_cpuid_entry(vcpu, function, index);
919 best = check_cpuid_limit(vcpu, function, index);
929 *eax = *ebx = *ecx = *edx = 0;
930 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found);
933 EXPORT_SYMBOL_GPL(kvm_cpuid);
935 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
937 u32 eax, ebx, ecx, edx;
939 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0))
942 eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
943 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
944 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true);
945 kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
946 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
947 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
948 kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
949 return kvm_skip_emulated_instruction(vcpu);
951 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);