cpuid.c 23.3 KB
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/*
 * 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>
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#include <linux/export.h>
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#include <linux/vmalloc.h>
#include <linux/uaccess.h>
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#include <linux/sched/stat.h>

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#include <asm/processor.h>
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#include <asm/user.h>
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#include <asm/fpu/xstate.h>
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#include "cpuid.h"
#include "lapic.h"
#include "mmu.h"
#include "trace.h"
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#include "pmu.h"
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static u32 xstate_required_size(u64 xstate_bv, bool compacted)
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{
	int feature_bit = 0;
	u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;

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	xstate_bv &= XFEATURE_MASK_EXTEND;
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	while (xstate_bv) {
		if (xstate_bv & 0x1) {
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		        u32 eax, ebx, ecx, edx, offset;
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		        cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
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			offset = compacted ? ret : ebx;
			ret = max(ret, offset + eax);
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		}

		xstate_bv >>= 1;
		feature_bit++;
	}

	return ret;
}

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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);

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u64 kvm_supported_xcr0(void)
{
	u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;

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	if (!kvm_mpx_supported())
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		xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
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	return xcr0;
}

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#define F(x) bit(X86_FEATURE_##x)

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/* For scattered features from cpufeatures.h; we currently expose none */
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#define KF(x) bit(KVM_CPUID_BIT_##x)

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int kvm_update_cpuid(struct kvm_vcpu *vcpu)
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{
	struct kvm_cpuid_entry2 *best;
	struct kvm_lapic *apic = vcpu->arch.apic;

	best = kvm_find_cpuid_entry(vcpu, 1, 0);
	if (!best)
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		return 0;
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	/* Update OSXSAVE bit */
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	if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) {
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		best->ecx &= ~F(OSXSAVE);
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		if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
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			best->ecx |= F(OSXSAVE);
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	}

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	best->edx &= ~F(APIC);
	if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE)
		best->edx |= F(APIC);

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	if (apic) {
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		if (best->ecx & F(TSC_DEADLINE_TIMER))
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			apic->lapic_timer.timer_mode_mask = 3 << 17;
		else
			apic->lapic_timer.timer_mode_mask = 1 << 17;
	}
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	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);
		}
	}

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	best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
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	if (!best) {
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		vcpu->arch.guest_supported_xcr0 = 0;
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		vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
	} else {
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		vcpu->arch.guest_supported_xcr0 =
			(best->eax | ((u64)best->edx << 32)) &
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			kvm_supported_xcr0();
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		vcpu->arch.guest_xstate_size = best->ebx =
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			xstate_required_size(vcpu->arch.xcr0, false);
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	}
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	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);

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	/*
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	 * The existing code assumes virtual address is 48-bit or 57-bit in the
	 * canonical address checks; exit if it is ever changed.
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	 */
	best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
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	if (best) {
		int vaddr_bits = (best->eax & 0xff00) >> 8;

		if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
			return -EINVAL;
	}
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	/* Update physical-address width */
	vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
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	kvm_mmu_reset_context(vcpu);
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	kvm_pmu_refresh(vcpu);
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	return 0;
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}

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;
		}
	}
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	if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
		entry->edx &= ~F(NX);
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		printk(KERN_INFO "kvm: guest NX capability removed\n");
	}
}

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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);

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/* 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;
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	struct kvm_cpuid_entry *cpuid_entries = NULL;
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	r = -E2BIG;
	if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
		goto out;
	r = -ENOMEM;
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	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;
	}
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	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);
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	r = kvm_update_cpuid(vcpu);
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out:
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	vfree(cpuid_entries);
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	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);
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	r = kvm_update_cpuid(vcpu);
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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;
}

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static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
				   u32 func, u32 index, int *nent, int maxnent)
{
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	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;

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	return 0;
}

static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
				 u32 index, int *nent, int maxnent)
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{
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	int r;
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	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;
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	unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
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	unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
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	unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
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	/* cpuid 1.edx */
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	const u32 kvm_cpuid_1_edx_x86_features =
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		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) |
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		F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
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		0 /* Reserved, DS, ACPI */ | F(MMX) |
		F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
		0 /* HTT, TM, Reserved, PBE */;
	/* cpuid 0x80000001.edx */
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	const u32 kvm_cpuid_8000_0001_edx_x86_features =
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		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 */
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	const u32 kvm_cpuid_1_ecx_x86_features =
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		/* NOTE: MONITOR (and MWAIT) are emulated as NOP,
		 * but *not* advertised to guests via CPUID ! */
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		F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
		0 /* DS-CPL, VMX, SMX, EST */ |
		0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
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		F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
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		F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
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		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 */
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	const u32 kvm_cpuid_8000_0001_ecx_x86_features =
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		F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
		F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
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		F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
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		0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);

	/* cpuid 0xC0000001.edx */
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	const u32 kvm_cpuid_C000_0001_edx_x86_features =
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		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 */
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	const u32 kvm_cpuid_7_0_ebx_x86_features =
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		F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
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		F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
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		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);
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	/* cpuid 0xD.1.eax */
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	const u32 kvm_cpuid_D_1_eax_x86_features =
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		F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
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	/* cpuid 7.0.ecx*/
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	const u32 kvm_cpuid_7_0_ecx_x86_features =
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		F(AVX512VBMI) | F(LA57) | F(PKU) |
		0 /*OSPKE*/ | F(AVX512_VPOPCNTDQ);
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	/* cpuid 7.0.edx*/
	const u32 kvm_cpuid_7_0_edx_x86_features =
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		F(AVX512_4VNNIW) | F(AVX512_4FMAPS);
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	/* all calls to cpuid_count() should be made on the same cpu */
	get_cpu();
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	r = -E2BIG;

	if (*nent >= maxnent)
		goto out;

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	do_cpuid_1_ent(entry, function, index);
	++*nent;

	switch (function) {
	case 0:
		entry->eax = min(entry->eax, (u32)0xd);
		break;
	case 1:
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		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);
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		/* 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;
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		for (t = 1; t < times; ++t) {
			if (*nent >= maxnent)
				goto out;

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			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 */
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		for (i = 1; ; ++i) {
			if (*nent >= maxnent)
				goto out;

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			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;
	}
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	case 6: /* Thermal management */
		entry->eax = 0x4; /* allow ARAT */
		entry->ebx = 0;
		entry->ecx = 0;
		entry->edx = 0;
		break;
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	case 7: {
		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
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		/* Mask ebx against host capability word 9 */
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		if (index == 0) {
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			entry->ebx &= kvm_cpuid_7_0_ebx_x86_features;
			cpuid_mask(&entry->ebx, CPUID_7_0_EBX);
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			// TSC_ADJUST is emulated
			entry->ebx |= F(TSC_ADJUST);
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			entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
			cpuid_mask(&entry->ecx, CPUID_7_ECX);
			/* PKU is not yet implemented for shadow paging. */
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			if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
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				entry->ecx &= ~F(PKU);
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			entry->edx &= kvm_cpuid_7_0_edx_x86_features;
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			cpuid_mask(&entry->edx, CPUID_7_EDX);
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		} else {
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			entry->ebx = 0;
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			entry->ecx = 0;
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			entry->edx = 0;
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		}
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		entry->eax = 0;
		break;
	}
	case 9:
		break;
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	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;
	}
A
Avi Kivity 已提交
518 519 520 521 522 523
	/* 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 */
524 525 526 527
		for (i = 1; ; ++i) {
			if (*nent >= maxnent)
				goto out;

A
Avi Kivity 已提交
528 529 530 531 532 533 534 535 536 537 538 539
			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;
540
		u64 supported = kvm_supported_xcr0();
A
Avi Kivity 已提交
541

542
		entry->eax &= supported;
543 544
		entry->ebx = xstate_required_size(supported, false);
		entry->ecx = entry->ebx;
545
		entry->edx &= supported >> 32;
A
Avi Kivity 已提交
546
		entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
P
Paolo Bonzini 已提交
547 548 549
		if (!supported)
			break;

550
		for (idx = 1, i = 1; idx < 64; ++idx) {
551
			u64 mask = ((u64)1 << idx);
552 553 554
			if (*nent >= maxnent)
				goto out;

A
Avi Kivity 已提交
555
			do_cpuid_1_ent(&entry[i], function, idx);
556
			if (idx == 1) {
557
				entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
558
				cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
559 560 561 562 563
				entry[i].ebx = 0;
				if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
					entry[i].ebx =
						xstate_required_size(supported,
								     true);
564 565 566 567 568 569 570 571
			} 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;
A
Avi Kivity 已提交
572 573 574 575 576 577 578 579
			entry[i].flags |=
			       KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
			++*nent;
			++i;
		}
		break;
	}
	case KVM_CPUID_SIGNATURE: {
580 581
		static const char signature[12] = "KVMKVMKVM\0\0";
		const u32 *sigptr = (const u32 *)signature;
582
		entry->eax = KVM_CPUID_FEATURES;
A
Avi Kivity 已提交
583 584 585 586 587 588 589 590 591 592
		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) |
593
			     (1 << KVM_FEATURE_PV_EOI) |
594 595
			     (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
			     (1 << KVM_FEATURE_PV_UNHALT);
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Avi Kivity 已提交
596 597 598 599 600 601 602 603 604 605 606 607

		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:
608 609 610 611
		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);
A
Avi Kivity 已提交
612
		break;
613 614 615 616 617 618 619
	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;
A
Avi Kivity 已提交
620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643
	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->ebx = entry->edx = 0;
		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:
644 645
		entry->edx &= kvm_cpuid_C000_0001_edx_x86_features;
		cpuid_mask(&entry->edx, CPUID_C000_0001_EDX);
A
Avi Kivity 已提交
646 647 648 649 650 651 652 653 654 655 656 657 658
		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);

659 660 661
	r = 0;

out:
A
Avi Kivity 已提交
662
	put_cpu();
663 664

	return r;
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Avi Kivity 已提交
665 666
}

B
Borislav Petkov 已提交
667 668 669 670 671 672 673 674 675
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);
}

A
Avi Kivity 已提交
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#undef F

678 679 680 681
struct kvm_cpuid_param {
	u32 func;
	u32 idx;
	bool has_leaf_count;
682
	bool (*qualifier)(const struct kvm_cpuid_param *param);
683 684
};

685
static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
686 687 688 689
{
	return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
}

B
Borislav Petkov 已提交
690 691 692 693
static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
				 __u32 num_entries, unsigned int ioctl_type)
{
	int i;
B
Borislav Petkov 已提交
694
	__u32 pad[3];
B
Borislav Petkov 已提交
695 696 697 698 699 700 701 702 703 704 705 706 707

	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++) {
B
Borislav Petkov 已提交
708 709 710 711
		if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
			return true;

		if (pad[0] || pad[1] || pad[2])
B
Borislav Petkov 已提交
712 713 714 715 716 717 718 719
			return true;
	}
	return false;
}

int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
			    struct kvm_cpuid_entry2 __user *entries,
			    unsigned int type)
A
Avi Kivity 已提交
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{
	struct kvm_cpuid_entry2 *cpuid_entries;
722
	int limit, nent = 0, r = -E2BIG, i;
A
Avi Kivity 已提交
723
	u32 func;
724
	static const struct kvm_cpuid_param param[] = {
725 726 727 728 729 730
		{ .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 },
	};
A
Avi Kivity 已提交
731 732 733 734 735

	if (cpuid->nent < 1)
		goto out;
	if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
		cpuid->nent = KVM_MAX_CPUID_ENTRIES;
B
Borislav Petkov 已提交
736 737 738 739

	if (sanity_check_entries(entries, cpuid->nent, type))
		return -EINVAL;

A
Avi Kivity 已提交
740
	r = -ENOMEM;
B
Borislav Petkov 已提交
741
	cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
A
Avi Kivity 已提交
742 743 744
	if (!cpuid_entries)
		goto out;

745 746
	r = 0;
	for (i = 0; i < ARRAY_SIZE(param); i++) {
747
		const struct kvm_cpuid_param *ent = &param[i];
A
Avi Kivity 已提交
748

749 750
		if (ent->qualifier && !ent->qualifier(ent))
			continue;
A
Avi Kivity 已提交
751

752
		r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
B
Borislav Petkov 已提交
753
				&nent, cpuid->nent, type);
A
Avi Kivity 已提交
754

755
		if (r)
A
Avi Kivity 已提交
756 757
			goto out_free;

758 759 760
		if (!ent->has_leaf_count)
			continue;

A
Avi Kivity 已提交
761
		limit = cpuid_entries[nent - 1].eax;
762 763
		for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
			r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
B
Borislav Petkov 已提交
764
				     &nent, cpuid->nent, type);
A
Avi Kivity 已提交
765

766
		if (r)
A
Avi Kivity 已提交
767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785
			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];
786 787 788
	struct kvm_cpuid_entry2 *ej;
	int j = i;
	int nent = vcpu->arch.cpuid_nent;
A
Avi Kivity 已提交
789 790 791

	e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
	/* when no next entry is found, the current entry[i] is reselected */
792 793 794 795 796 797 798 799
	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;
A
Avi Kivity 已提交
800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858
}

/* 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);
}

859 860
bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
	       u32 *ecx, u32 *edx, bool check_limit)
A
Avi Kivity 已提交
861
{
862
	u32 function = *eax, index = *ecx;
A
Avi Kivity 已提交
863
	struct kvm_cpuid_entry2 *best;
864
	bool entry_found = true;
A
Avi Kivity 已提交
865 866 867

	best = kvm_find_cpuid_entry(vcpu, function, index);

868 869 870 871 872
	if (!best) {
		entry_found = false;
		if (!check_limit)
			goto out;

A
Avi Kivity 已提交
873
		best = check_cpuid_limit(vcpu, function, index);
874
	}
A
Avi Kivity 已提交
875

876
out:
A
Avi Kivity 已提交
877
	if (best) {
878 879 880 881 882 883
		*eax = best->eax;
		*ebx = best->ebx;
		*ecx = best->ecx;
		*edx = best->edx;
	} else
		*eax = *ebx = *ecx = *edx = 0;
884 885
	trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found);
	return entry_found;
886
}
887
EXPORT_SYMBOL_GPL(kvm_cpuid);
888

889
int kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
890
{
891
	u32 eax, ebx, ecx, edx;
892

K
Kyle Huey 已提交
893 894 895
	if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0))
		return 1;

896
	eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
897
	ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
898
	kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true);
899 900 901 902
	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);
903
	return kvm_skip_emulated_instruction(vcpu);
A
Avi Kivity 已提交
904 905
}
EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);