Lines Matching +full:use +full:- +full:rtm
1 // SPDX-License-Identifier: GPL-2.0-only
3 * Kernel-based Virtual Machine driver for Linux
66 /* Scattered Flag - For features that are scattered by cpufeatures.h. */
74 * Magic value used by KVM when querying userspace-provided CPUID entries and
80 #define KVM_CPUID_INDEX_NOT_SIGNIFICANT -1ull
89 * KVM has a semi-arbitrary rule that querying the guest's CPUID model in cpuid_entry2_find()
93 * path, e.g. the core VM-Enter/VM-Exit run loop. Nothing will break in cpuid_entry2_find()
103 if (e->function != function) in cpuid_entry2_find()
107 * If the index isn't significant, use the first entry with a in cpuid_entry2_find()
111 if (!(e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) || e->index == index) in cpuid_entry2_find()
116 * Similarly, use the first matching entry if KVM is doing a in cpuid_entry2_find()
141 * The existing code assumes virtual address is 48-bit or 57-bit in the in kvm_check_cpuid()
147 int vaddr_bits = (best->eax & 0xff00) >> 8; in kvm_check_cpuid()
150 return -EINVAL; in kvm_check_cpuid()
161 xfeatures = best->eax | ((u64)best->edx << 32); in kvm_check_cpuid()
166 return fpu_enable_guest_xfd_features(&vcpu->arch.guest_fpu, xfeatures); in kvm_check_cpuid()
176 if (nent != vcpu->arch.cpuid_nent) in kvm_cpuid_check_equal()
177 return -EINVAL; in kvm_cpuid_check_equal()
180 orig = &vcpu->arch.cpuid_entries[i]; in kvm_cpuid_check_equal()
181 if (e2[i].function != orig->function || in kvm_cpuid_check_equal()
182 e2[i].index != orig->index || in kvm_cpuid_check_equal()
183 e2[i].flags != orig->flags || in kvm_cpuid_check_equal()
184 e2[i].eax != orig->eax || e2[i].ebx != orig->ebx || in kvm_cpuid_check_equal()
185 e2[i].ecx != orig->ecx || e2[i].edx != orig->edx) in kvm_cpuid_check_equal()
186 return -EINVAL; in kvm_cpuid_check_equal()
205 signature[0] = entry->ebx; in __kvm_get_hypervisor_cpuid()
206 signature[1] = entry->ecx; in __kvm_get_hypervisor_cpuid()
207 signature[2] = entry->edx; in __kvm_get_hypervisor_cpuid()
211 cpuid.limit = entry->eax; in __kvm_get_hypervisor_cpuid()
223 return __kvm_get_hypervisor_cpuid(vcpu->arch.cpuid_entries, in kvm_get_hypervisor_cpuid()
224 vcpu->arch.cpuid_nent, sig); in kvm_get_hypervisor_cpuid()
236 u32 base = vcpu->arch.kvm_cpuid.base; in kvm_find_kvm_cpuid_features()
241 return __kvm_find_kvm_cpuid_features(vcpu->arch.cpuid_entries, in kvm_find_kvm_cpuid_features()
242 vcpu->arch.cpuid_nent, base); in kvm_find_kvm_cpuid_features()
254 vcpu->arch.pv_cpuid.features = best->eax; in kvm_update_pv_runtime()
269 return (best->eax | ((u64)best->edx << 32)) & kvm_caps.supported_xcr0; in cpuid_get_supported_xcr0()
286 vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE); in __kvm_update_cpuid_runtime()
290 if (best && boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) in __kvm_update_cpuid_runtime()
296 best->ebx = xstate_required_size(vcpu->arch.xcr0, false); in __kvm_update_cpuid_runtime()
301 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); in __kvm_update_cpuid_runtime()
306 if (kvm_hlt_in_guest(vcpu->kvm) && best) in __kvm_update_cpuid_runtime()
307 best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT); in __kvm_update_cpuid_runtime()
310 if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) { in __kvm_update_cpuid_runtime()
314 vcpu->arch.ia32_misc_enable_msr & in __kvm_update_cpuid_runtime()
321 __kvm_update_cpuid_runtime(vcpu, vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent); in kvm_update_cpuid_runtime()
332 return entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX; in kvm_cpuid_has_hyperv()
346 return is_guest_vendor_amd(entry->ebx, entry->ecx, entry->edx) || in guest_cpuid_is_amd_or_hygon()
347 is_guest_vendor_hygon(entry->ebx, entry->ecx, entry->edx); in guest_cpuid_is_amd_or_hygon()
352 struct kvm_lapic *apic = vcpu->arch.apic; in kvm_vcpu_after_set_cpuid()
357 bitmap_zero(vcpu->arch.governed_features.enabled, in kvm_vcpu_after_set_cpuid()
361 * If TDP is enabled, let the guest use GBPAGES if they're supported in in kvm_vcpu_after_set_cpuid()
363 * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA in kvm_vcpu_after_set_cpuid()
365 * _can't_ solve the problem because GVA->GPA walks aren't visible to in kvm_vcpu_after_set_cpuid()
379 apic->lapic_timer.timer_mode_mask = 3 << 17; in kvm_vcpu_after_set_cpuid()
381 apic->lapic_timer.timer_mode_mask = 1 << 17; in kvm_vcpu_after_set_cpuid()
386 vcpu->arch.guest_supported_xcr0 = in kvm_vcpu_after_set_cpuid()
387 cpuid_get_supported_xcr0(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent); in kvm_vcpu_after_set_cpuid()
391 vcpu->arch.is_amd_compatible = guest_cpuid_is_amd_or_hygon(vcpu); in kvm_vcpu_after_set_cpuid()
392 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); in kvm_vcpu_after_set_cpuid()
393 vcpu->arch.reserved_gpa_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu); in kvm_vcpu_after_set_cpuid()
396 vcpu->arch.cr4_guest_rsvd_bits = in kvm_vcpu_after_set_cpuid()
399 kvm_hv_set_cpuid(vcpu, kvm_cpuid_has_hyperv(vcpu->arch.cpuid_entries, in kvm_vcpu_after_set_cpuid()
400 vcpu->arch.cpuid_nent)); in kvm_vcpu_after_set_cpuid()
417 if (!best || best->eax < 0x80000008) in cpuid_query_maxphyaddr()
421 return best->eax & 0xff; in cpuid_query_maxphyaddr()
475 kvfree(vcpu->arch.cpuid_entries); in kvm_set_cpuid()
476 vcpu->arch.cpuid_entries = e2; in kvm_set_cpuid()
477 vcpu->arch.cpuid_nent = nent; in kvm_set_cpuid()
479 vcpu->arch.kvm_cpuid = kvm_get_hypervisor_cpuid(vcpu, KVM_SIGNATURE); in kvm_set_cpuid()
481 vcpu->arch.xen.cpuid = kvm_get_hypervisor_cpuid(vcpu, XEN_SIGNATURE); in kvm_set_cpuid()
497 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) in kvm_vcpu_ioctl_set_cpuid()
498 return -E2BIG; in kvm_vcpu_ioctl_set_cpuid()
500 if (cpuid->nent) { in kvm_vcpu_ioctl_set_cpuid()
501 e = vmemdup_array_user(entries, cpuid->nent, sizeof(*e)); in kvm_vcpu_ioctl_set_cpuid()
505 e2 = kvmalloc_array(cpuid->nent, sizeof(*e2), GFP_KERNEL_ACCOUNT); in kvm_vcpu_ioctl_set_cpuid()
507 r = -ENOMEM; in kvm_vcpu_ioctl_set_cpuid()
511 for (i = 0; i < cpuid->nent; i++) { in kvm_vcpu_ioctl_set_cpuid()
524 r = kvm_set_cpuid(vcpu, e2, cpuid->nent); in kvm_vcpu_ioctl_set_cpuid()
541 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) in kvm_vcpu_ioctl_set_cpuid2()
542 return -E2BIG; in kvm_vcpu_ioctl_set_cpuid2()
544 if (cpuid->nent) { in kvm_vcpu_ioctl_set_cpuid2()
545 e2 = vmemdup_array_user(entries, cpuid->nent, sizeof(*e2)); in kvm_vcpu_ioctl_set_cpuid2()
550 r = kvm_set_cpuid(vcpu, e2, cpuid->nent); in kvm_vcpu_ioctl_set_cpuid2()
561 if (cpuid->nent < vcpu->arch.cpuid_nent) in kvm_vcpu_ioctl_get_cpuid2()
562 return -E2BIG; in kvm_vcpu_ioctl_get_cpuid2()
564 if (copy_to_user(entries, vcpu->arch.cpuid_entries, in kvm_vcpu_ioctl_get_cpuid2()
565 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) in kvm_vcpu_ioctl_get_cpuid2()
566 return -EFAULT; in kvm_vcpu_ioctl_get_cpuid2()
568 cpuid->nent = vcpu->arch.cpuid_nent; in kvm_vcpu_ioctl_get_cpuid2()
589 /* Use kvm_cpu_cap_mask for leafs that aren't KVM-only. */ in kvm_cpu_cap_init_kvm_defined()
599 /* Use kvm_cpu_cap_init_kvm_defined for KVM-only leafs. */ in kvm_cpu_cap_mask()
620 BUILD_BUG_ON(sizeof(kvm_cpu_caps) - (NKVMCAPINTS * sizeof(*kvm_cpu_caps)) > in kvm_set_cpu_caps()
624 sizeof(kvm_cpu_caps) - (NKVMCAPINTS * sizeof(*kvm_cpu_caps))); in kvm_set_cpu_caps()
632 0 /* DS-CPL, VMX, SMX, EST */ | in kvm_set_cpu_caps()
633 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | in kvm_set_cpu_caps()
657 F(RTM) | F(ZERO_FCS_FDS) | 0 /*MPX*/ | F(AVX512F) | in kvm_set_cpu_caps()
764 * record that in cpufeatures so use them. in kvm_set_cpu_caps()
777 * The preference is to use SPEC CTRL MSR instead of the in kvm_set_cpu_caps()
809 * Synthesize "LFENCE is serializing" into the AMD-defined entry in in kvm_set_cpu_caps()
811 * kernel. LFENCE_RDTSC was a Linux-defined synthetic feature long in kvm_set_cpu_caps()
855 if (array->nent >= array->maxnent) in get_next_cpuid()
858 return &array->entries[array->nent++]; in get_next_cpuid()
870 entry->function = function; in do_host_cpuid()
871 entry->index = index; in do_host_cpuid()
880 * would result in out-of-bounds calls to do_host_cpuid. in do_host_cpuid()
895 cpuid_count(entry->function, entry->index, in do_host_cpuid()
896 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); in do_host_cpuid()
899 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; in do_host_cpuid()
908 if (array->nent >= array->maxnent) in __do_cpuid_func_emulated()
909 return -E2BIG; in __do_cpuid_func_emulated()
911 entry = &array->entries[array->nent]; in __do_cpuid_func_emulated()
912 entry->function = func; in __do_cpuid_func_emulated()
913 entry->index = 0; in __do_cpuid_func_emulated()
914 entry->flags = 0; in __do_cpuid_func_emulated()
918 entry->eax = 7; in __do_cpuid_func_emulated()
919 ++array->nent; in __do_cpuid_func_emulated()
922 entry->ecx = F(MOVBE); in __do_cpuid_func_emulated()
923 ++array->nent; in __do_cpuid_func_emulated()
926 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; in __do_cpuid_func_emulated()
927 entry->eax = 0; in __do_cpuid_func_emulated()
929 entry->ecx = F(RDPID); in __do_cpuid_func_emulated()
930 ++array->nent; in __do_cpuid_func_emulated()
947 r = -E2BIG; in __do_cpuid_func()
956 entry->eax = min(entry->eax, 0x24U); in __do_cpuid_func()
966 * time, with the least-significant byte in EAX enumerating the in __do_cpuid_func()
978 WARN_ON_ONCE((entry->eax & 0xff) > 1); in __do_cpuid_func()
987 for (i = 1; entry->eax & 0x1f; ++i) { in __do_cpuid_func()
994 entry->eax = 0x4; /* allow ARAT */ in __do_cpuid_func()
995 entry->ebx = 0; in __do_cpuid_func()
996 entry->ecx = 0; in __do_cpuid_func()
997 entry->edx = 0; in __do_cpuid_func()
1001 max_idx = entry->eax = min(entry->eax, 2u); in __do_cpuid_func()
1014 entry->ebx = 0; in __do_cpuid_func()
1015 entry->ecx = 0; in __do_cpuid_func()
1023 entry->ecx = 0; in __do_cpuid_func()
1024 entry->ebx = 0; in __do_cpuid_func()
1025 entry->eax = 0; in __do_cpuid_func()
1033 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1049 entry->eax = eax.full; in __do_cpuid_func()
1050 entry->ebx = kvm_pmu_cap.events_mask; in __do_cpuid_func()
1051 entry->ecx = 0; in __do_cpuid_func()
1052 entry->edx = edx.full; in __do_cpuid_func()
1061 entry->eax = entry->ebx = entry->ecx = 0; in __do_cpuid_func()
1067 entry->eax &= permitted_xcr0; in __do_cpuid_func()
1068 entry->ebx = xstate_required_size(permitted_xcr0, false); in __do_cpuid_func()
1069 entry->ecx = entry->ebx; in __do_cpuid_func()
1070 entry->edx &= permitted_xcr0 >> 32; in __do_cpuid_func()
1079 if (entry->eax & (F(XSAVES)|F(XSAVEC))) in __do_cpuid_func()
1080 entry->ebx = xstate_required_size(permitted_xcr0 | permitted_xss, in __do_cpuid_func()
1084 entry->ebx = 0; in __do_cpuid_func()
1086 entry->ecx &= permitted_xss; in __do_cpuid_func()
1087 entry->edx &= permitted_xss >> 32; in __do_cpuid_func()
1104 * invalid sub-leafs. Only valid sub-leafs should in __do_cpuid_func()
1105 * reach this point, and they should have a non-zero in __do_cpuid_func()
1108 * on whether this is an XCR0- or IA32_XSS-managed area. in __do_cpuid_func()
1110 if (WARN_ON_ONCE(!entry->eax || (entry->ecx & 0x1) != s_state)) { in __do_cpuid_func()
1111 --array->nent; in __do_cpuid_func()
1116 entry->ecx &= ~BIT_ULL(2); in __do_cpuid_func()
1117 entry->edx = 0; in __do_cpuid_func()
1124 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1129 * Index 0: Sub-features, MISCSELECT (a.k.a extended features) in __do_cpuid_func()
1130 * and max enclave sizes. The SGX sub-features and MISCSELECT in __do_cpuid_func()
1135 entry->ebx &= SGX_MISC_EXINFO; in __do_cpuid_func()
1144 * privileged attributes that require explicit opt-in from in __do_cpuid_func()
1148 entry->eax &= SGX_ATTR_PRIV_MASK | SGX_ATTR_UNPRIV_MASK; in __do_cpuid_func()
1149 entry->ebx &= 0; in __do_cpuid_func()
1154 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1158 for (i = 1, max_idx = entry->eax; i <= max_idx; ++i) { in __do_cpuid_func()
1166 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1170 for (i = 1, max_idx = entry->eax; i <= max_idx; ++i) { in __do_cpuid_func()
1177 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1185 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1194 avx10_version = min_t(u8, entry->ebx & 0xff, 1); in __do_cpuid_func()
1196 entry->ebx |= avx10_version; in __do_cpuid_func()
1198 entry->eax = 0; in __do_cpuid_func()
1199 entry->ecx = 0; in __do_cpuid_func()
1200 entry->edx = 0; in __do_cpuid_func()
1205 entry->eax = KVM_CPUID_FEATURES; in __do_cpuid_func()
1206 entry->ebx = sigptr[0]; in __do_cpuid_func()
1207 entry->ecx = sigptr[1]; in __do_cpuid_func()
1208 entry->edx = sigptr[2]; in __do_cpuid_func()
1212 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | in __do_cpuid_func()
1227 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); in __do_cpuid_func()
1229 entry->ebx = 0; in __do_cpuid_func()
1230 entry->ecx = 0; in __do_cpuid_func()
1231 entry->edx = 0; in __do_cpuid_func()
1234 entry->eax = min(entry->eax, 0x80000022); in __do_cpuid_func()
1244 * highest Intel leaf which QEMU tries to use as the guest's in __do_cpuid_func()
1248 if (entry->eax >= 0x8000001d && in __do_cpuid_func()
1251 entry->eax = max(entry->eax, 0x80000021); in __do_cpuid_func()
1254 entry->ebx &= ~GENMASK(27, 16); in __do_cpuid_func()
1263 entry->edx &= ~GENMASK(17, 16); in __do_cpuid_func()
1269 entry->edx &= boot_cpu_data.x86_power; in __do_cpuid_func()
1270 entry->eax = entry->ebx = entry->ecx = 0; in __do_cpuid_func()
1275 * use. in __do_cpuid_func()
1285 * support 5-level TDP. in __do_cpuid_func()
1287 unsigned int virt_as = max((entry->eax >> 8) & 0xff, 48U); in __do_cpuid_func()
1291 * If TDP (NPT) is disabled use the adjusted host MAXPHYADDR as in __do_cpuid_func()
1296 * If TDP is enabled, use the raw bare metal MAXPHYADDR as in __do_cpuid_func()
1299 * that it's capped at 48 bits if 5-level TDP isn't supported in __do_cpuid_func()
1307 phys_as = entry->eax & 0xff; in __do_cpuid_func()
1313 entry->eax = phys_as | (virt_as << 8) | (g_phys_as << 16); in __do_cpuid_func()
1314 entry->ecx &= ~(GENMASK(31, 16) | GENMASK(11, 8)); in __do_cpuid_func()
1315 entry->edx = 0; in __do_cpuid_func()
1321 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1324 entry->eax = 1; /* SVM revision 1 */ in __do_cpuid_func()
1325 entry->ebx = 8; /* Lets support 8 ASIDs in case we add proper in __do_cpuid_func()
1327 entry->ecx = 0; /* Reserved */ in __do_cpuid_func()
1331 entry->ecx = entry->edx = 0; in __do_cpuid_func()
1334 entry->eax &= GENMASK(2, 0); in __do_cpuid_func()
1335 entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1339 entry->eax = entry->ebx = entry->ecx = 0; in __do_cpuid_func()
1340 entry->edx = 0; /* reserved */ in __do_cpuid_func()
1344 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1348 entry->ebx &= ~GENMASK(31, 12); in __do_cpuid_func()
1353 entry->ebx &= ~GENMASK(11, 6); in __do_cpuid_func()
1357 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1360 entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1367 entry->ecx = entry->edx = 0; in __do_cpuid_func()
1369 entry->eax = entry->ebx; in __do_cpuid_func()
1382 entry->ebx = ebx.full; in __do_cpuid_func()
1388 entry->eax = min(entry->eax, 0xC0000004); in __do_cpuid_func()
1399 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; in __do_cpuid_func()
1436 limit = array->entries[array->nent - 1].eax; in get_cpuid_func()
1456 * We want to make sure that ->padding is being passed clean from in sanity_check_entries()
1457 * userspace in case we want to use it for something in the future. in sanity_check_entries()
1486 if (cpuid->nent < 1) in kvm_dev_ioctl_get_cpuid()
1487 return -E2BIG; in kvm_dev_ioctl_get_cpuid()
1488 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) in kvm_dev_ioctl_get_cpuid()
1489 cpuid->nent = KVM_MAX_CPUID_ENTRIES; in kvm_dev_ioctl_get_cpuid()
1491 if (sanity_check_entries(entries, cpuid->nent, type)) in kvm_dev_ioctl_get_cpuid()
1492 return -EINVAL; in kvm_dev_ioctl_get_cpuid()
1494 array.entries = kvcalloc(cpuid->nent, sizeof(struct kvm_cpuid_entry2), GFP_KERNEL); in kvm_dev_ioctl_get_cpuid()
1496 return -ENOMEM; in kvm_dev_ioctl_get_cpuid()
1498 array.maxnent = cpuid->nent; in kvm_dev_ioctl_get_cpuid()
1505 cpuid->nent = array.nent; in kvm_dev_ioctl_get_cpuid()
1509 r = -EFAULT; in kvm_dev_ioctl_get_cpuid()
1519 return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent, in kvm_find_cpuid_entry_index()
1527 return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent, in kvm_find_cpuid_entry()
1533 * Intel CPUID semantics treats any query for an out-of-range leaf as if the
1538 * A leaf is considered out-of-range if its function is higher than the maximum
1543 * ranges described as "<base> - <top>[,<base2> - <top2>] inclusive. A primary
1547 * - Basic: 0x00000000 - 0x3fffffff, 0x50000000 - 0x7fffffff
1548 * - Hypervisor: 0x40000000 - 0x4fffffff
1549 * - Extended: 0x80000000 - 0xbfffffff
1550 * - Centaur: 0xc0000000 - 0xcfffffff
1552 * The Hypervisor class is further subdivided into sub-classes that each act as
1555 * CPUID sub-classes are:
1557 * - HyperV: 0x40000000 - 0x400000ff
1558 * - KVM: 0x40000100 - 0x400001ff
1570 if (is_guest_vendor_amd(basic->ebx, basic->ecx, basic->edx) || in get_out_of_range_cpuid_entry()
1571 is_guest_vendor_hygon(basic->ebx, basic->ecx, basic->edx)) in get_out_of_range_cpuid_entry()
1581 if (class && function <= class->eax) in get_out_of_range_cpuid_entry()
1590 *fn_ptr = basic->eax; in get_out_of_range_cpuid_entry()
1597 return kvm_find_cpuid_entry_index(vcpu, basic->eax, index); in get_out_of_range_cpuid_entry()
1616 *eax = entry->eax; in kvm_cpuid()
1617 *ebx = entry->ebx; in kvm_cpuid()
1618 *ecx = entry->ecx; in kvm_cpuid()
1619 *edx = entry->edx; in kvm_cpuid()
1624 *ebx &= ~(F(RTM) | F(HLE)); in kvm_cpuid()
1632 * When leaf 0BH or 1FH is defined, CL is pass-through in kvm_cpuid()
1642 *edx = entry->edx; in kvm_cpuid()