text: /*
   * Kernel-based Virtual Machine driver for Linux
   * cpuid support routines
   *
   * derived from arch/x86/kvm/x86.c
   *
   * Copyright 2011 Red Hat, Inc. and/or its affiliates.
   * Copyright IBM Corporation, 2008
   *
   * This work is licensed under the terms of the GNU GPL, version 2.  See
   * the COPYING file in the top-level directory.
   *
   */
  
  #include <linux/kvm_host.h>
  #include <linux/export.h>
  #include <linux/vmalloc.h>
  #include <linux/uaccess.h>
  #include <linux/sched/stat.h>
  
  #include <asm/processor.h>
  #include <asm/user.h>
  #include <asm/fpu/xstate.h>
  #include "cpuid.h"
  #include "lapic.h"
  #include "mmu.h"
  #include "trace.h"
  #include "pmu.h"
  
  static u32 xstate_required_size(u64 xstate_bv, bool compacted)
  {
  	int feature_bit = 0;
  	u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
  
  	xstate_bv &= XFEATURE_MASK_EXTEND;
  	while (xstate_bv) {
  		if (xstate_bv & 0x1) {
  		        u32 eax, ebx, ecx, edx, offset;
  		        cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
  			offset = compacted ? ret : ebx;
  			ret = max(ret, offset + eax);
  		}
  
  		xstate_bv >>= 1;
  		feature_bit++;
  	}
  
  	return ret;
  }
  
  bool kvm_mpx_supported(void)
  {
  	return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR))
  		 && kvm_x86_ops->mpx_supported());
  }
  EXPORT_SYMBOL_GPL(kvm_mpx_supported);
  
  u64 kvm_supported_xcr0(void)
  {
  	u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
  
  	if (!kvm_mpx_supported())
  		xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
  
  	return xcr0;
  }
  
  #define F(x) bit(X86_FEATURE_##x)
  
  /* For scattered features from cpufeatures.h; we currently expose none */
  #define KF(x) bit(KVM_CPUID_BIT_##x)
  
  int kvm_update_cpuid(struct kvm_vcpu *vcpu)
  {
  	struct kvm_cpuid_entry2 *best;
  	struct kvm_lapic *apic = vcpu->arch.apic;
  
  	best = kvm_find_cpuid_entry(vcpu, 1, 0);
  	if (!best)
  		return 0;
  
  	/* Update OSXSAVE bit */
  	if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) {
  		best->ecx &= ~F(OSXSAVE);
  		if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
  			best->ecx |= F(OSXSAVE);
  	}
  
  	best->edx &= ~F(APIC);
  	if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE)
  		best->edx |= F(APIC);
  
  	if (apic) {
  		if (best->ecx & F(TSC_DEADLINE_TIMER))
  			apic->lapic_timer.timer_mode_mask = 3 << 17;
  		else
  			apic->lapic_timer.timer_mode_mask = 1 << 17;
  	}
  
  	best = kvm_find_cpuid_entry(vcpu, 7, 0);
  	if (best) {
  		/* Update OSPKE bit */
  		if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) {
  			best->ecx &= ~F(OSPKE);
  			if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE))
  				best->ecx |= F(OSPKE);
  		}
  	}
  
  	best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
  	if (!best) {
  		vcpu->arch.guest_supported_xcr0 = 0;
  		vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
  	} else {
  		vcpu->arch.guest_supported_xcr0 =
  			(best->eax | ((u64)best->edx << 32)) &
  			kvm_supported_xcr0();
  		vcpu->arch.guest_xstate_size = best->ebx =
  			xstate_required_size(vcpu->arch.xcr0, false);
  	}
  
  	best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
  	if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
  		best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
  
  	/*
  	 * The existing code assumes virtual address is 48-bit or 57-bit in the
  	 * canonical address checks; exit if it is ever changed.
  	 */
  	best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
  	if (best) {
  		int vaddr_bits = (best->eax & 0xff00) >> 8;
  
  		if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
  			return -EINVAL;
  	}
  
  	/* Update physical-address width */
  	vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
  	kvm_mmu_reset_context(vcpu);
  
  	kvm_pmu_refresh(vcpu);
  	return 0;
  }
  
  static int is_efer_nx(void)
  {
  	unsigned long long efer = 0;
  
  	rdmsrl_safe(MSR_EFER, &efer);
  	return efer & EFER_NX;
  }
  
  static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
  {
  	int i;
  	struct kvm_cpuid_entry2 *e, *entry;
  
  	entry = NULL;
  	for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
  		e = &vcpu->arch.cpuid_entries[i];
  		if (e->function == 0x80000001) {
  			entry = e;
  			break;
  		}
  	}
  	if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
  		entry->edx &= ~F(NX);
  		printk(KERN_INFO "kvm: guest NX capability removed\n");
  	}
  }
  
  int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
  {
  	struct kvm_cpuid_entry2 *best;
  
  	best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
  	if (!best || best->eax < 0x80000008)
  		goto not_found;
  	best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
  	if (best)
  		return best->eax & 0xff;
  not_found:
  	return 36;
  }
  EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
  
  /* when an old userspace process fills a new kernel module */
  int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
  			     struct kvm_cpuid *cpuid,
  			     struct kvm_cpuid_entry __user *entries)
  {
  	int r, i;
  	struct kvm_cpuid_entry *cpuid_entries = NULL;
  
  	r = -E2BIG;
  	if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
  		goto out;
  	r = -ENOMEM;
  	if (cpuid->nent) {
  		cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) *
  					cpuid->nent);
  		if (!cpuid_entries)
  			goto out;
  		r = -EFAULT;
  		if (copy_from_user(cpuid_entries, entries,
  				   cpuid->nent * sizeof(struct kvm_cpuid_entry)))
  			goto out;
  	}
  	for (i = 0; i < cpuid->nent; i++) {
  		vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
  		vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
  		vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
  		vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
  		vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
  		vcpu->arch.cpuid_entries[i].index = 0;
  		vcpu->arch.cpuid_entries[i].flags = 0;
  		vcpu->arch.cpuid_entries[i].padding[0] = 0;
  		vcpu->arch.cpuid_entries[i].padding[1] = 0;
  		vcpu->arch.cpuid_entries[i].padding[2] = 0;
  	}
  	vcpu->arch.cpuid_nent = cpuid->nent;
  	cpuid_fix_nx_cap(vcpu);
  	kvm_apic_set_version(vcpu);
  	kvm_x86_ops->cpuid_update(vcpu);
  	r = kvm_update_cpuid(vcpu);
  
  out:
  	vfree(cpuid_entries);
  	return r;
  }
  
  int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
  			      struct kvm_cpuid2 *cpuid,
  			      struct kvm_cpuid_entry2 __user *entries)
  {
  	int r;
  
  	r = -E2BIG;
  	if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
  		goto out;
  	r = -EFAULT;
  	if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
  			   cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
  		goto out;
  	vcpu->arch.cpuid_nent = cpuid->nent;
  	kvm_apic_set_version(vcpu);
  	kvm_x86_ops->cpuid_update(vcpu);
  	r = kvm_update_cpuid(vcpu);
  out:
  	return r;
  }
  
  int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
  			      struct kvm_cpuid2 *cpuid,
  			      struct kvm_cpuid_entry2 __user *entries)
  {
  	int r;
  
  	r = -E2BIG;
  	if (cpuid->nent < vcpu->arch.cpuid_nent)
  		goto out;
  	r = -EFAULT;
  	if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
  			 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
  		goto out;
  	return 0;
  
  out:
  	cpuid->nent = vcpu->arch.cpuid_nent;
  	return r;
  }
  
  static void cpuid_mask(u32 *word, int wordnum)
  {
  	*word &= boot_cpu_data.x86_capability[wordnum];
  }
  
  static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
  			   u32 index)
  {
  	entry->function = function;
  	entry->index = index;
  	cpuid_count(entry->function, entry->index,
  		    &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
  	entry->flags = 0;
  }
  
  static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
  				   u32 func, u32 index, int *nent, int maxnent)
  {
  	switch (func) {
  	case 0:
  		entry->eax = 1;		/* only one leaf currently */
  		++*nent;
  		break;
  	case 1:
  		entry->ecx = F(MOVBE);
  		++*nent;
  		break;
  	default:
  		break;
  	}
  
  	entry->function = func;
  	entry->index = index;
  
  	return 0;
  }
  
  static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
  				 u32 index, int *nent, int maxnent)
  {
  	int r;
  	unsigned f_nx = is_efer_nx() ? F(NX) : 0;
  #ifdef CONFIG_X86_64
  	unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
  				? F(GBPAGES) : 0;
  	unsigned f_lm = F(LM);
  #else
  	unsigned f_gbpages = 0;
  	unsigned f_lm = 0;
  #endif
  	unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
  	unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
  	unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
  	unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
  
  	/* cpuid 1.edx */
  	const u32 kvm_cpuid_1_edx_x86_features =
  		F(FPU) | F(VME) | F(DE) | F(PSE) |
  		F(TSC) | F(MSR) | F(PAE) | F(MCE) |
  		F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
  		F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
  		F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
  		0 /* Reserved, DS, ACPI */ | F(MMX) |
  		F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
  		0 /* HTT, TM, Reserved, PBE */;
  	/* cpuid 0x80000001.edx */
  	const u32 kvm_cpuid_8000_0001_edx_x86_features =
  		F(FPU) | F(VME) | F(DE) | F(PSE) |
  		F(TSC) | F(MSR) | F(PAE) | F(MCE) |
  		F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
  		F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
  		F(PAT) | F(PSE36) | 0 /* Reserved */ |
  		f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
  		F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
  		0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
  	/* cpuid 1.ecx */
  	const u32 kvm_cpuid_1_ecx_x86_features =
  		/* NOTE: MONITOR (and MWAIT) are emulated as NOP,
  		 * but *not* advertised to guests via CPUID ! */
  		F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
  		0 /* DS-CPL, VMX, SMX, EST */ |
  		0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
  		F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
  		F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
  		F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
  		0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
  		F(F16C) | F(RDRAND);
  	/* cpuid 0x80000001.ecx */
  	const u32 kvm_cpuid_8000_0001_ecx_x86_features =
  		F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
  		F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
  		F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
  		0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
  
  	/* cpuid 0x80000008.ebx */
  	const u32 kvm_cpuid_8000_0008_ebx_x86_features =
  		F(AMD_IBPB) | F(AMD_IBRS) | F(VIRT_SSBD);
  
  	/* cpuid 0xC0000001.edx */
  	const u32 kvm_cpuid_C000_0001_edx_x86_features =
  		F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
  		F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
  		F(PMM) | F(PMM_EN);
  
  	/* cpuid 7.0.ebx */
  	const u32 kvm_cpuid_7_0_ebx_x86_features =
  		F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
  		F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
  		F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
  		F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) |
  		F(SHA_NI) | F(AVX512BW) | F(AVX512VL);
  
  	/* cpuid 0xD.1.eax */
  	const u32 kvm_cpuid_D_1_eax_x86_features =
  		F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
  
  	/* cpuid 7.0.ecx*/
  	const u32 kvm_cpuid_7_0_ecx_x86_features =
  		F(AVX512VBMI) | F(LA57) | F(PKU) |
  		0 /*OSPKE*/ | F(AVX512_VPOPCNTDQ);
  
  	/* cpuid 7.0.edx*/
  	const u32 kvm_cpuid_7_0_edx_x86_features =
  		F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
  		F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES);
  
  	/* all calls to cpuid_count() should be made on the same cpu */
  	get_cpu();
  
  	r = -E2BIG;
  
  	if (*nent >= maxnent)
  		goto out;
  
  	do_cpuid_1_ent(entry, function, index);
  	++*nent;
  
  	switch (function) {
  	case 0:
  		entry->eax = min(entry->eax, (u32)0xd);
  		break;
  	case 1:
  		entry->edx &= kvm_cpuid_1_edx_x86_features;
  		cpuid_mask(&entry->edx, CPUID_1_EDX);
  		entry->ecx &= kvm_cpuid_1_ecx_x86_features;
  		cpuid_mask(&entry->ecx, CPUID_1_ECX);
  		/* we support x2apic emulation even if host does not support
  		 * it since we emulate x2apic in software */
  		entry->ecx |= F(X2APIC);
  		break;
  	/* function 2 entries are STATEFUL. That is, repeated cpuid commands
  	 * may return different values. This forces us to get_cpu() before
  	 * issuing the first command, and also to emulate this annoying behavior
  	 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
  	case 2: {
  		int t, times = entry->eax & 0xff;
  
  		entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
  		entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
  		for (t = 1; t < times; ++t) {
  			if (*nent >= maxnent)
  				goto out;
  
  			do_cpuid_1_ent(&entry[t], function, 0);
  			entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
  			++*nent;
  		}
  		break;
  	}
  	/* function 4 has additional index. */
  	case 4: {
  		int i, cache_type;
  
  		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
  		/* read more entries until cache_type is zero */
  		for (i = 1; ; ++i) {
  			if (*nent >= maxnent)
  				goto out;
  
  			cache_type = entry[i - 1].eax & 0x1f;
  			if (!cache_type)
  				break;
  			do_cpuid_1_ent(&entry[i], function, i);
  			entry[i].flags |=
  			       KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
  			++*nent;
  		}
  		break;
  	}
  	case 6: /* Thermal management */
  		entry->eax = 0x4; /* allow ARAT */
  		entry->ebx = 0;
  		entry->ecx = 0;
  		entry->edx = 0;
  		break;
  	case 7: {
  		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
  		/* Mask ebx against host capability word 9 */
  		if (index == 0) {
  			entry->ebx &= kvm_cpuid_7_0_ebx_x86_features;
  			cpuid_mask(&entry->ebx, CPUID_7_0_EBX);
  			// TSC_ADJUST is emulated
  			entry->ebx |= F(TSC_ADJUST);
  			entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
  			cpuid_mask(&entry->ecx, CPUID_7_ECX);
  			/* PKU is not yet implemented for shadow paging. */
  			if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
  				entry->ecx &= ~F(PKU);
  			entry->edx &= kvm_cpuid_7_0_edx_x86_features;
  			cpuid_mask(&entry->edx, CPUID_7_EDX);
  			/*
  			 * We emulate ARCH_CAPABILITIES in software even
  			 * if the host doesn't support it.
  			 */
  			entry->edx |= F(ARCH_CAPABILITIES);
  		} else {
  			entry->ebx = 0;
  			entry->ecx = 0;
  			entry->edx = 0;
  		}
  		entry->eax = 0;
  		break;
  	}
  	case 9:
  		break;
  	case 0xa: { /* Architectural Performance Monitoring */
  		struct x86_pmu_capability cap;
  		union cpuid10_eax eax;
  		union cpuid10_edx edx;
  
  		perf_get_x86_pmu_capability(&cap);
  
  		/*
  		 * Only support guest architectural pmu on a host
  		 * with architectural pmu.
  		 */
  		if (!cap.version)
  			memset(&cap, 0, sizeof(cap));
  
  		eax.split.version_id = min(cap.version, 2);
  		eax.split.num_counters = cap.num_counters_gp;
  		eax.split.bit_width = cap.bit_width_gp;
  		eax.split.mask_length = cap.events_mask_len;
  
  		edx.split.num_counters_fixed = cap.num_counters_fixed;
  		edx.split.bit_width_fixed = cap.bit_width_fixed;
  		edx.split.reserved = 0;
  
  		entry->eax = eax.full;
  		entry->ebx = cap.events_mask;
  		entry->ecx = 0;
  		entry->edx = edx.full;
  		break;
  	}
  	/* function 0xb has additional index. */
  	case 0xb: {
  		int i, level_type;
  
  		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
  		/* read more entries until level_type is zero */
  		for (i = 1; ; ++i) {
  			if (*nent >= maxnent)
  				goto out;
  
  			level_type = entry[i - 1].ecx & 0xff00;
  			if (!level_type)
  				break;
  			do_cpuid_1_ent(&entry[i], function, i);
  			entry[i].flags |=
  			       KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
  			++*nent;
  		}
  		break;
  	}
  	case 0xd: {
  		int idx, i;
  		u64 supported = kvm_supported_xcr0();
  
  		entry->eax &= supported;
  		entry->ebx = xstate_required_size(supported, false);
  		entry->ecx = entry->ebx;
  		entry->edx &= supported >> 32;
  		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
  		if (!supported)
  			break;
  
  		for (idx = 1, i = 1; idx < 64; ++idx) {
  			u64 mask = ((u64)1 << idx);
  			if (*nent >= maxnent)
  				goto out;
  
  			do_cpuid_1_ent(&entry[i], function, idx);
  			if (idx == 1) {
  				entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
  				cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
  				entry[i].ebx = 0;
  				if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
  					entry[i].ebx =
  						xstate_required_size(supported,
  								     true);
  			} else {
  				if (entry[i].eax == 0 || !(supported & mask))
  					continue;
  				if (WARN_ON_ONCE(entry[i].ecx & 1))
  					continue;
  			}
  			entry[i].ecx = 0;
  			entry[i].edx = 0;
  			entry[i].flags |=
  			       KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
  			++*nent;
  			++i;
  		}
  		break;
  	}
  	case KVM_CPUID_SIGNATURE: {
  		static const char signature[12] = "KVMKVMKVM\0\0";
  		const u32 *sigptr = (const u32 *)signature;
  		entry->eax = KVM_CPUID_FEATURES;
  		entry->ebx = sigptr[0];
  		entry->ecx = sigptr[1];
  		entry->edx = sigptr[2];
  		break;
  	}
  	case KVM_CPUID_FEATURES:
  		entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
  			     (1 << KVM_FEATURE_NOP_IO_DELAY) |
  			     (1 << KVM_FEATURE_CLOCKSOURCE2) |
  			     (1 << KVM_FEATURE_ASYNC_PF) |
  			     (1 << KVM_FEATURE_PV_EOI) |
  			     (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
  			     (1 << KVM_FEATURE_PV_UNHALT) |
  			     (1 << KVM_FEATURE_ASYNC_PF_VMEXIT);
  
  		if (sched_info_on())
  			entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
  
  		entry->ebx = 0;
  		entry->ecx = 0;
  		entry->edx = 0;
  		break;
  	case 0x80000000:
  		entry->eax = min(entry->eax, 0x8000001a);
  		break;
  	case 0x80000001:
  		entry->edx &= kvm_cpuid_8000_0001_edx_x86_features;
  		cpuid_mask(&entry->edx, CPUID_8000_0001_EDX);
  		entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features;
  		cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX);
  		break;
  	case 0x80000007: /* Advanced power management */
  		/* invariant TSC is CPUID.80000007H:EDX[8] */
  		entry->edx &= (1 << 8);
  		/* mask against host */
  		entry->edx &= boot_cpu_data.x86_power;
  		entry->eax = entry->ebx = entry->ecx = 0;
  		break;
  	case 0x80000008: {
  		unsigned g_phys_as = (entry->eax >> 16) & 0xff;
  		unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
  		unsigned phys_as = entry->eax & 0xff;
  
  		if (!g_phys_as)
  			g_phys_as = phys_as;
  		entry->eax = g_phys_as | (virt_as << 8);
  		entry->edx = 0;
  		/*
  		 * IBRS, IBPB and VIRT_SSBD aren't necessarily present in
  		 * hardware cpuid
  		 */
  		if (boot_cpu_has(X86_FEATURE_AMD_IBPB))
  			entry->ebx |= F(AMD_IBPB);
  		if (boot_cpu_has(X86_FEATURE_AMD_IBRS))
  			entry->ebx |= F(AMD_IBRS);
  		if (boot_cpu_has(X86_FEATURE_VIRT_SSBD))
  			entry->ebx |= F(VIRT_SSBD);
  		entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
  		cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
  		if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD))
  			entry->ebx |= F(VIRT_SSBD);
  		break;
  	}
  	case 0x80000019:
  		entry->ecx = entry->edx = 0;
  		break;
  	case 0x8000001a:
  		break;
  	case 0x8000001d:
  		break;
  	/*Add support for Centaur's CPUID instruction*/
  	case 0xC0000000:
  		/*Just support up to 0xC0000004 now*/
  		entry->eax = min(entry->eax, 0xC0000004);
  		break;
  	case 0xC0000001:
  		entry->edx &= kvm_cpuid_C000_0001_edx_x86_features;
  		cpuid_mask(&entry->edx, CPUID_C000_0001_EDX);
  		break;
  	case 3: /* Processor serial number */
  	case 5: /* MONITOR/MWAIT */
  	case 0xC0000002:
  	case 0xC0000003:
  	case 0xC0000004:
  	default:
  		entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
  		break;
  	}
  
  	kvm_x86_ops->set_supported_cpuid(function, entry);
  
  	r = 0;
  
  out:
  	put_cpu();
  
  	return r;
  }
  
  static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
  			u32 idx, int *nent, int maxnent, unsigned int type)
  {
  	if (type == KVM_GET_EMULATED_CPUID)
  		return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
  
  	return __do_cpuid_ent(entry, func, idx, nent, maxnent);
  }
  
  #undef F
  
  struct kvm_cpuid_param {
  	u32 func;
  	u32 idx;
  	bool has_leaf_count;
  	bool (*qualifier)(const struct kvm_cpuid_param *param);
  };
  
  static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
  {
  	return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
  }
  
  static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
  				 __u32 num_entries, unsigned int ioctl_type)
  {
  	int i;
  	__u32 pad[3];
  
  	if (ioctl_type != KVM_GET_EMULATED_CPUID)
  		return false;
  
  	/*
  	 * We want to make sure that ->padding is being passed clean from
  	 * userspace in case we want to use it for something in the future.
  	 *
  	 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
  	 * have to give ourselves satisfied only with the emulated side. /me
  	 * sheds a tear.
  	 */
  	for (i = 0; i < num_entries; i++) {
  		if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
  			return true;
  
  		if (pad[0] || pad[1] || pad[2])
  			return true;
  	}
  	return false;
  }
  
  int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
  			    struct kvm_cpuid_entry2 __user *entries,
  			    unsigned int type)
  {
  	struct kvm_cpuid_entry2 *cpuid_entries;
  	int limit, nent = 0, r = -E2BIG, i;
  	u32 func;
  	static const struct kvm_cpuid_param param[] = {
  		{ .func = 0, .has_leaf_count = true },
  		{ .func = 0x80000000, .has_leaf_count = true },
  		{ .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
  		{ .func = KVM_CPUID_SIGNATURE },
  		{ .func = KVM_CPUID_FEATURES },
  	};
  
  	if (cpuid->nent < 1)
  		goto out;
  	if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
  		cpuid->nent = KVM_MAX_CPUID_ENTRIES;
  
  	if (sanity_check_entries(entries, cpuid->nent, type))
  		return -EINVAL;
  
  	r = -ENOMEM;
  	cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
  	if (!cpuid_entries)
  		goto out;
  
  	r = 0;
  	for (i = 0; i < ARRAY_SIZE(param); i++) {
  		const struct kvm_cpuid_param *ent = &param[i];
  
  		if (ent->qualifier && !ent->qualifier(ent))
  			continue;
  
  		r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
  				&nent, cpuid->nent, type);
  
  		if (r)
  			goto out_free;
  
  		if (!ent->has_leaf_count)
  			continue;
  
  		limit = cpuid_entries[nent - 1].eax;
  		for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
  			r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
  				     &nent, cpuid->nent, type);
  
  		if (r)
  			goto out_free;
  	}
  
  	r = -EFAULT;
  	if (copy_to_user(entries, cpuid_entries,
  			 nent * sizeof(struct kvm_cpuid_entry2)))
  		goto out_free;
  	cpuid->nent = nent;
  	r = 0;
  
  out_free:
  	vfree(cpuid_entries);
  out:
  	return r;
  }
  
  static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
  {
  	struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
  	struct kvm_cpuid_entry2 *ej;
  	int j = i;
  	int nent = vcpu->arch.cpuid_nent;
  
  	e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
  	/* when no next entry is found, the current entry[i] is reselected */
  	do {
  		j = (j + 1) % nent;
  		ej = &vcpu->arch.cpuid_entries[j];
  	} while (ej->function != e->function);
  
  	ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
  
  	return j;
  }
  
  /* find an entry with matching function, matching index (if needed), and that
   * should be read next (if it's stateful) */
  static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
  	u32 function, u32 index)
  {
  	if (e->function != function)
  		return 0;
  	if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
  		return 0;
  	if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
  	    !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
  		return 0;
  	return 1;
  }
  
  struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
  					      u32 function, u32 index)
  {
  	int i;
  	struct kvm_cpuid_entry2 *best = NULL;
  
  	for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
  		struct kvm_cpuid_entry2 *e;
  
  		e = &vcpu->arch.cpuid_entries[i];
  		if (is_matching_cpuid_entry(e, function, index)) {
  			if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
  				move_to_next_stateful_cpuid_entry(vcpu, i);
  			best = e;
  			break;
  		}
  	}
  	return best;
  }
  EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
  
  /*
   * If no match is found, check whether we exceed the vCPU's limit
   * and return the content of the highest valid _standard_ leaf instead.
   * This is to satisfy the CPUID specification.
   */
  static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
                                                    u32 function, u32 index)
  {
  	struct kvm_cpuid_entry2 *maxlevel;
  
  	maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
  	if (!maxlevel || maxlevel->eax >= function)
  		return NULL;
  	if (function & 0x80000000) {
  		maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
  		if (!maxlevel)
  			return NULL;
  	}
  	return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
  }
  
  bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
  	       u32 *ecx, u32 *edx, bool check_limit)
  {
  	u32 function = *eax, index = *ecx;
  	struct kvm_cpuid_entry2 *best;
  	bool entry_found = true;
  
  	best = kvm_find_cpuid_entry(vcpu, function, index);
  
  	if (!best) {
  		entry_found = false;
  		if (!check_limit)
  			goto out;
  
  		best = check_cpuid_limit(vcpu, function, index);
  	}
  
  out:
  	if (best) {
  		*eax = best->eax;
  		*ebx = best->ebx;
  		*ecx = best->ecx;
  		*edx = best->edx;
  	} else
  		*eax = *ebx = *ecx = *edx = 0;
  	trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found);
  	return entry_found;
  }
  EXPORT_SYMBOL_GPL(kvm_cpuid);
  
  int kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
  {
  	u32 eax, ebx, ecx, edx;
  
  	if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0))
  		return 1;
  
  	eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
  	ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
  	kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true);
  	kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
  	kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
  	kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
  	kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
  	return kvm_skip_emulated_instruction(vcpu);
  }
  EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
  