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-rw-r--r--arch/x86/kvm/cpuid.c1151
1 files changed, 1151 insertions, 0 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
new file mode 100644
index 000000000..8b07e4861
--- /dev/null
+++ b/arch/x86/kvm/cpuid.c
@@ -0,0 +1,1151 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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
+ */
+
+#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"
+
+/*
+ * Unlike "struct cpuinfo_x86.x86_capability", kvm_cpu_caps doesn't need to be
+ * aligned to sizeof(unsigned long) because it's not accessed via bitops.
+ */
+u32 kvm_cpu_caps[NCAPINTS] __read_mostly;
+EXPORT_SYMBOL_GPL(kvm_cpu_caps);
+
+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;
+}
+
+#define F feature_bit
+
+static inline struct kvm_cpuid_entry2 *cpuid_entry2_find(
+ struct kvm_cpuid_entry2 *entries, int nent, u32 function, u32 index)
+{
+ struct kvm_cpuid_entry2 *e;
+ int i;
+
+ for (i = 0; i < nent; i++) {
+ e = &entries[i];
+
+ if (e->function == function && (e->index == index ||
+ !(e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX)))
+ return e;
+ }
+
+ return NULL;
+}
+
+static int kvm_check_cpuid(struct kvm_cpuid_entry2 *entries, int nent)
+{
+ struct kvm_cpuid_entry2 *best;
+
+ /*
+ * The existing code assumes virtual address is 48-bit or 57-bit in the
+ * canonical address checks; exit if it is ever changed.
+ */
+ best = cpuid_entry2_find(entries, nent, 0x80000008, 0);
+ if (best) {
+ int vaddr_bits = (best->eax & 0xff00) >> 8;
+
+ if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+void kvm_update_pv_runtime(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpuid_entry2 *best;
+
+ best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0);
+
+ /*
+ * save the feature bitmap to avoid cpuid lookup for every PV
+ * operation
+ */
+ if (best)
+ vcpu->arch.pv_cpuid.features = best->eax;
+}
+
+void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
+{
+ struct kvm_cpuid_entry2 *best;
+
+ best = kvm_find_cpuid_entry(vcpu, 1, 0);
+ if (best) {
+ /* Update OSXSAVE bit */
+ if (boot_cpu_has(X86_FEATURE_XSAVE))
+ cpuid_entry_change(best, X86_FEATURE_OSXSAVE,
+ kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE));
+
+ cpuid_entry_change(best, X86_FEATURE_APIC,
+ vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE);
+ }
+
+ best = kvm_find_cpuid_entry(vcpu, 7, 0);
+ if (best && boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7)
+ cpuid_entry_change(best, X86_FEATURE_OSPKE,
+ kvm_read_cr4_bits(vcpu, X86_CR4_PKE));
+
+ best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
+ if (best)
+ best->ebx = xstate_required_size(vcpu->arch.xcr0, false);
+
+ best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
+ if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
+ cpuid_entry_has(best, X86_FEATURE_XSAVEC)))
+ best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
+
+ best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0);
+ if (kvm_hlt_in_guest(vcpu->kvm) && best &&
+ (best->eax & (1 << KVM_FEATURE_PV_UNHALT)))
+ best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT);
+
+ if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) {
+ best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
+ if (best)
+ cpuid_entry_change(best, X86_FEATURE_MWAIT,
+ vcpu->arch.ia32_misc_enable_msr &
+ MSR_IA32_MISC_ENABLE_MWAIT);
+ }
+}
+
+static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
+{
+ struct kvm_lapic *apic = vcpu->arch.apic;
+ struct kvm_cpuid_entry2 *best;
+
+ best = kvm_find_cpuid_entry(vcpu, 1, 0);
+ if (best && apic) {
+ if (cpuid_entry_has(best, X86_FEATURE_TSC_DEADLINE_TIMER))
+ apic->lapic_timer.timer_mode_mask = 3 << 17;
+ else
+ apic->lapic_timer.timer_mode_mask = 1 << 17;
+
+ kvm_apic_set_version(vcpu);
+ }
+
+ best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
+ if (!best)
+ vcpu->arch.guest_supported_xcr0 = 0;
+ else
+ vcpu->arch.guest_supported_xcr0 =
+ (best->eax | ((u64)best->edx << 32)) & supported_xcr0;
+
+ kvm_update_pv_runtime(vcpu);
+
+ vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
+ kvm_mmu_reset_context(vcpu);
+
+ kvm_pmu_refresh(vcpu);
+ vcpu->arch.cr4_guest_rsvd_bits =
+ __cr4_reserved_bits(guest_cpuid_has, vcpu);
+
+ vcpu->arch.cr3_lm_rsvd_bits = rsvd_bits(cpuid_maxphyaddr(vcpu), 63);
+
+ /* Invoke the vendor callback only after the above state is updated. */
+ kvm_x86_ops.vcpu_after_set_cpuid(vcpu);
+}
+
+static int is_efer_nx(void)
+{
+ return host_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 && cpuid_entry_has(entry, X86_FEATURE_NX) && !is_efer_nx()) {
+ cpuid_entry_clear(entry, X86_FEATURE_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;
+}
+
+/* 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 *e = NULL;
+ struct kvm_cpuid_entry2 *e2 = NULL;
+
+ if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
+ return -E2BIG;
+
+ if (cpuid->nent) {
+ e = vmemdup_user(entries, array_size(sizeof(*e), cpuid->nent));
+ if (IS_ERR(e))
+ return PTR_ERR(e);
+
+ e2 = kvmalloc_array(cpuid->nent, sizeof(*e2), GFP_KERNEL_ACCOUNT);
+ if (!e2) {
+ r = -ENOMEM;
+ goto out_free_cpuid;
+ }
+ }
+ for (i = 0; i < cpuid->nent; i++) {
+ e2[i].function = e[i].function;
+ e2[i].eax = e[i].eax;
+ e2[i].ebx = e[i].ebx;
+ e2[i].ecx = e[i].ecx;
+ e2[i].edx = e[i].edx;
+ e2[i].index = 0;
+ e2[i].flags = 0;
+ e2[i].padding[0] = 0;
+ e2[i].padding[1] = 0;
+ e2[i].padding[2] = 0;
+ }
+
+ r = kvm_check_cpuid(e2, cpuid->nent);
+ if (r) {
+ kvfree(e2);
+ goto out_free_cpuid;
+ }
+
+ kvfree(vcpu->arch.cpuid_entries);
+ vcpu->arch.cpuid_entries = e2;
+ vcpu->arch.cpuid_nent = cpuid->nent;
+
+ cpuid_fix_nx_cap(vcpu);
+ kvm_update_cpuid_runtime(vcpu);
+ kvm_vcpu_after_set_cpuid(vcpu);
+
+out_free_cpuid:
+ kvfree(e);
+
+ return r;
+}
+
+int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
+ struct kvm_cpuid2 *cpuid,
+ struct kvm_cpuid_entry2 __user *entries)
+{
+ struct kvm_cpuid_entry2 *e2 = NULL;
+ int r;
+
+ if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
+ return -E2BIG;
+
+ if (cpuid->nent) {
+ e2 = vmemdup_user(entries, array_size(sizeof(*e2), cpuid->nent));
+ if (IS_ERR(e2))
+ return PTR_ERR(e2);
+ }
+
+ r = kvm_check_cpuid(e2, cpuid->nent);
+ if (r) {
+ kvfree(e2);
+ return r;
+ }
+
+ kvfree(vcpu->arch.cpuid_entries);
+ vcpu->arch.cpuid_entries = e2;
+ vcpu->arch.cpuid_nent = cpuid->nent;
+
+ kvm_update_cpuid_runtime(vcpu);
+ kvm_vcpu_after_set_cpuid(vcpu);
+
+ return 0;
+}
+
+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 __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask)
+{
+ const struct cpuid_reg cpuid = x86_feature_cpuid(leaf * 32);
+ struct kvm_cpuid_entry2 entry;
+
+ reverse_cpuid_check(leaf);
+ kvm_cpu_caps[leaf] &= mask;
+
+ cpuid_count(cpuid.function, cpuid.index,
+ &entry.eax, &entry.ebx, &entry.ecx, &entry.edx);
+
+ kvm_cpu_caps[leaf] &= *__cpuid_entry_get_reg(&entry, cpuid.reg);
+}
+
+void kvm_set_cpu_caps(void)
+{
+ unsigned int f_nx = is_efer_nx() ? F(NX) : 0;
+#ifdef CONFIG_X86_64
+ unsigned int f_gbpages = F(GBPAGES);
+ unsigned int f_lm = F(LM);
+#else
+ unsigned int f_gbpages = 0;
+ unsigned int f_lm = 0;
+#endif
+
+ BUILD_BUG_ON(sizeof(kvm_cpu_caps) >
+ sizeof(boot_cpu_data.x86_capability));
+
+ memcpy(&kvm_cpu_caps, &boot_cpu_data.x86_capability,
+ sizeof(kvm_cpu_caps));
+
+ kvm_cpu_cap_mask(CPUID_1_ECX,
+ /*
+ * 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 */ | F(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)
+ );
+ /* KVM emulates x2apic in software irrespective of host support. */
+ kvm_cpu_cap_set(X86_FEATURE_X2APIC);
+
+ kvm_cpu_cap_mask(CPUID_1_EDX,
+ 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 */
+ );
+
+ kvm_cpu_cap_mask(CPUID_7_0_EBX,
+ F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
+ F(BMI2) | F(ERMS) | 0 /*INVPCID*/ | F(RTM) | 0 /*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) | 0 /*INTEL_PT*/
+ );
+
+ kvm_cpu_cap_mask(CPUID_7_ECX,
+ F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | F(RDPID) |
+ F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) |
+ F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) |
+ F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B) | 0 /*WAITPKG*/
+ );
+ /* Set LA57 based on hardware capability. */
+ if (cpuid_ecx(7) & F(LA57))
+ kvm_cpu_cap_set(X86_FEATURE_LA57);
+
+ /*
+ * PKU not yet implemented for shadow paging and requires OSPKE
+ * to be set on the host. Clear it if that is not the case
+ */
+ if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
+ kvm_cpu_cap_clear(X86_FEATURE_PKU);
+
+ kvm_cpu_cap_mask(CPUID_7_EDX,
+ F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
+ F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) |
+ F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM) |
+ F(SERIALIZE) | F(TSXLDTRK)
+ );
+
+ /* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */
+ kvm_cpu_cap_set(X86_FEATURE_TSC_ADJUST);
+ kvm_cpu_cap_set(X86_FEATURE_ARCH_CAPABILITIES);
+
+ if (boot_cpu_has(X86_FEATURE_IBPB) && boot_cpu_has(X86_FEATURE_IBRS))
+ kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL);
+ if (boot_cpu_has(X86_FEATURE_STIBP))
+ kvm_cpu_cap_set(X86_FEATURE_INTEL_STIBP);
+ if (boot_cpu_has(X86_FEATURE_AMD_SSBD))
+ kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL_SSBD);
+
+ kvm_cpu_cap_mask(CPUID_7_1_EAX,
+ F(AVX512_BF16)
+ );
+
+ kvm_cpu_cap_mask(CPUID_D_1_EAX,
+ F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | F(XSAVES)
+ );
+
+ kvm_cpu_cap_mask(CPUID_8000_0001_ECX,
+ 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) |
+ F(TOPOEXT) | F(PERFCTR_CORE)
+ );
+
+ kvm_cpu_cap_mask(CPUID_8000_0001_EDX,
+ 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)
+ );
+
+ if (!tdp_enabled && IS_ENABLED(CONFIG_X86_64))
+ kvm_cpu_cap_set(X86_FEATURE_GBPAGES);
+
+ kvm_cpu_cap_mask(CPUID_8000_0008_EBX,
+ F(CLZERO) | F(XSAVEERPTR) |
+ F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
+ F(AMD_SSB_NO) | F(AMD_STIBP) | F(AMD_STIBP_ALWAYS_ON)
+ );
+
+ /*
+ * AMD has separate bits for each SPEC_CTRL bit.
+ * arch/x86/kernel/cpu/bugs.c is kind enough to
+ * record that in cpufeatures so use them.
+ */
+ if (boot_cpu_has(X86_FEATURE_IBPB))
+ kvm_cpu_cap_set(X86_FEATURE_AMD_IBPB);
+ if (boot_cpu_has(X86_FEATURE_IBRS))
+ kvm_cpu_cap_set(X86_FEATURE_AMD_IBRS);
+ if (boot_cpu_has(X86_FEATURE_STIBP))
+ kvm_cpu_cap_set(X86_FEATURE_AMD_STIBP);
+ if (boot_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD))
+ kvm_cpu_cap_set(X86_FEATURE_AMD_SSBD);
+ if (!boot_cpu_has_bug(X86_BUG_SPEC_STORE_BYPASS))
+ kvm_cpu_cap_set(X86_FEATURE_AMD_SSB_NO);
+ /*
+ * The preference is to use SPEC CTRL MSR instead of the
+ * VIRT_SPEC MSR.
+ */
+ if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) &&
+ !boot_cpu_has(X86_FEATURE_AMD_SSBD))
+ kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD);
+
+ if (cpu_feature_enabled(X86_FEATURE_SRSO_NO))
+ kvm_cpu_cap_set(X86_FEATURE_SRSO_NO);
+
+ /*
+ * Hide all SVM features by default, SVM will set the cap bits for
+ * features it emulates and/or exposes for L1.
+ */
+ kvm_cpu_cap_mask(CPUID_8000_000A_EDX, 0);
+
+ kvm_cpu_cap_mask(CPUID_C000_0001_EDX,
+ 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)
+ );
+}
+EXPORT_SYMBOL_GPL(kvm_set_cpu_caps);
+
+struct kvm_cpuid_array {
+ struct kvm_cpuid_entry2 *entries;
+ int maxnent;
+ int nent;
+};
+
+static struct kvm_cpuid_entry2 *get_next_cpuid(struct kvm_cpuid_array *array)
+{
+ if (array->nent >= array->maxnent)
+ return NULL;
+
+ return &array->entries[array->nent++];
+}
+
+static struct kvm_cpuid_entry2 *do_host_cpuid(struct kvm_cpuid_array *array,
+ u32 function, u32 index)
+{
+ struct kvm_cpuid_entry2 *entry = get_next_cpuid(array);
+
+ if (!entry)
+ return NULL;
+
+ entry->function = function;
+ entry->index = index;
+ entry->flags = 0;
+
+ cpuid_count(entry->function, entry->index,
+ &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
+
+ switch (function) {
+ case 4:
+ case 7:
+ case 0xb:
+ case 0xd:
+ case 0xf:
+ case 0x10:
+ case 0x12:
+ case 0x14:
+ case 0x17:
+ case 0x18:
+ case 0x1f:
+ case 0x8000001d:
+ entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+ break;
+ }
+
+ return entry;
+}
+
+static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func)
+{
+ struct kvm_cpuid_entry2 *entry;
+
+ if (array->nent >= array->maxnent)
+ return -E2BIG;
+
+ entry = &array->entries[array->nent];
+ entry->function = func;
+ entry->index = 0;
+ entry->flags = 0;
+
+ switch (func) {
+ case 0:
+ entry->eax = 7;
+ ++array->nent;
+ break;
+ case 1:
+ entry->ecx = F(MOVBE);
+ ++array->nent;
+ break;
+ case 7:
+ entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+ entry->eax = 0;
+ if (kvm_cpu_cap_has(X86_FEATURE_RDTSCP))
+ entry->ecx = F(RDPID);
+ ++array->nent;
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
+{
+ struct kvm_cpuid_entry2 *entry;
+ int r, i, max_idx;
+
+ /* all calls to cpuid_count() should be made on the same cpu */
+ get_cpu();
+
+ r = -E2BIG;
+
+ entry = do_host_cpuid(array, function, 0);
+ if (!entry)
+ goto out;
+
+ switch (function) {
+ case 0:
+ /* Limited to the highest leaf implemented in KVM. */
+ entry->eax = min(entry->eax, 0x1fU);
+ break;
+ case 1:
+ cpuid_entry_override(entry, CPUID_1_EDX);
+ cpuid_entry_override(entry, CPUID_1_ECX);
+ break;
+ case 2:
+ /*
+ * On ancient CPUs, function 2 entries are STATEFUL. That is,
+ * CPUID(function=2, index=0) may return different results each
+ * time, with the least-significant byte in EAX enumerating the
+ * number of times software should do CPUID(2, 0).
+ *
+ * Modern CPUs, i.e. every CPU KVM has *ever* run on are less
+ * idiotic. Intel's SDM states that EAX & 0xff "will always
+ * return 01H. Software should ignore this value and not
+ * interpret it as an informational descriptor", while AMD's
+ * APM states that CPUID(2) is reserved.
+ *
+ * WARN if a frankenstein CPU that supports virtualization and
+ * a stateful CPUID.0x2 is encountered.
+ */
+ WARN_ON_ONCE((entry->eax & 0xff) > 1);
+ break;
+ /* functions 4 and 0x8000001d have additional index. */
+ case 4:
+ case 0x8000001d:
+ /*
+ * Read entries until the cache type in the previous entry is
+ * zero, i.e. indicates an invalid entry.
+ */
+ for (i = 1; entry->eax & 0x1f; ++i) {
+ entry = do_host_cpuid(array, function, i);
+ if (!entry)
+ goto out;
+ }
+ break;
+ case 6: /* Thermal management */
+ entry->eax = 0x4; /* allow ARAT */
+ entry->ebx = 0;
+ entry->ecx = 0;
+ entry->edx = 0;
+ break;
+ /* function 7 has additional index. */
+ case 7:
+ entry->eax = min(entry->eax, 1u);
+ cpuid_entry_override(entry, CPUID_7_0_EBX);
+ cpuid_entry_override(entry, CPUID_7_ECX);
+ cpuid_entry_override(entry, CPUID_7_EDX);
+
+ /* KVM only supports 0x7.0 and 0x7.1, capped above via min(). */
+ if (entry->eax == 1) {
+ entry = do_host_cpuid(array, function, 1);
+ if (!entry)
+ goto out;
+
+ cpuid_entry_override(entry, CPUID_7_1_EAX);
+ entry->ebx = 0;
+ entry->ecx = 0;
+ entry->edx = 0;
+ }
+ break;
+ case 0xa: { /* Architectural Performance Monitoring */
+ struct x86_pmu_capability cap;
+ union cpuid10_eax eax;
+ union cpuid10_edx edx;
+
+ if (!static_cpu_has(X86_FEATURE_ARCH_PERFMON)) {
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ }
+
+ 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 = min(cap.num_counters_fixed, MAX_FIXED_COUNTERS);
+ edx.split.bit_width_fixed = cap.bit_width_fixed;
+ if (cap.version)
+ edx.split.anythread_deprecated = 1;
+ edx.split.reserved1 = 0;
+ edx.split.reserved2 = 0;
+
+ entry->eax = eax.full;
+ entry->ebx = cap.events_mask;
+ entry->ecx = 0;
+ entry->edx = edx.full;
+ break;
+ }
+ case 0x1f:
+ case 0xb:
+ /*
+ * No topology; a valid topology is indicated by the presence
+ * of subleaf 1.
+ */
+ entry->eax = entry->ebx = entry->ecx = 0;
+ break;
+ case 0xd:
+ entry->eax &= supported_xcr0;
+ entry->ebx = xstate_required_size(supported_xcr0, false);
+ entry->ecx = entry->ebx;
+ entry->edx &= supported_xcr0 >> 32;
+ if (!supported_xcr0)
+ break;
+
+ entry = do_host_cpuid(array, function, 1);
+ if (!entry)
+ goto out;
+
+ cpuid_entry_override(entry, CPUID_D_1_EAX);
+ if (entry->eax & (F(XSAVES)|F(XSAVEC)))
+ entry->ebx = xstate_required_size(supported_xcr0 | supported_xss,
+ true);
+ else {
+ WARN_ON_ONCE(supported_xss != 0);
+ entry->ebx = 0;
+ }
+ entry->ecx &= supported_xss;
+ entry->edx &= supported_xss >> 32;
+
+ for (i = 2; i < 64; ++i) {
+ bool s_state;
+ if (supported_xcr0 & BIT_ULL(i))
+ s_state = false;
+ else if (supported_xss & BIT_ULL(i))
+ s_state = true;
+ else
+ continue;
+
+ entry = do_host_cpuid(array, function, i);
+ if (!entry)
+ goto out;
+
+ /*
+ * The supported check above should have filtered out
+ * invalid sub-leafs. Only valid sub-leafs should
+ * reach this point, and they should have a non-zero
+ * save state size. Furthermore, check whether the
+ * processor agrees with supported_xcr0/supported_xss
+ * on whether this is an XCR0- or IA32_XSS-managed area.
+ */
+ if (WARN_ON_ONCE(!entry->eax || (entry->ecx & 0x1) != s_state)) {
+ --array->nent;
+ continue;
+ }
+ entry->edx = 0;
+ }
+ break;
+ /* Intel PT */
+ case 0x14:
+ if (!kvm_cpu_cap_has(X86_FEATURE_INTEL_PT)) {
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ }
+
+ for (i = 1, max_idx = entry->eax; i <= max_idx; ++i) {
+ if (!do_host_cpuid(array, function, i))
+ goto out;
+ }
+ 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_PV_TLB_FLUSH) |
+ (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) |
+ (1 << KVM_FEATURE_PV_SEND_IPI) |
+ (1 << KVM_FEATURE_POLL_CONTROL) |
+ (1 << KVM_FEATURE_PV_SCHED_YIELD) |
+ (1 << KVM_FEATURE_ASYNC_PF_INT);
+
+ 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, 0x8000001f);
+ break;
+ case 0x80000001:
+ entry->ebx &= ~GENMASK(27, 16);
+ cpuid_entry_override(entry, CPUID_8000_0001_EDX);
+ cpuid_entry_override(entry, CPUID_8000_0001_ECX);
+ break;
+ case 0x80000006:
+ /* Drop reserved bits, pass host L2 cache and TLB info. */
+ entry->edx &= ~GENMASK(17, 16);
+ 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;
+
+ /*
+ * Use bare metal's MAXPHADDR if the CPU doesn't report guest
+ * MAXPHYADDR separately, or if TDP (NPT) is disabled, as the
+ * guest version "applies only to guests using nested paging".
+ */
+ if (!g_phys_as || !tdp_enabled)
+ g_phys_as = phys_as;
+
+ entry->eax = g_phys_as | (virt_as << 8);
+ entry->ecx &= ~(GENMASK(31, 16) | GENMASK(11, 8));
+ entry->edx = 0;
+ cpuid_entry_override(entry, CPUID_8000_0008_EBX);
+ break;
+ }
+ case 0x8000000A:
+ if (!kvm_cpu_cap_has(X86_FEATURE_SVM)) {
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ }
+ entry->eax = 1; /* SVM revision 1 */
+ entry->ebx = 8; /* Lets support 8 ASIDs in case we add proper
+ ASID emulation to nested SVM */
+ entry->ecx = 0; /* Reserved */
+ cpuid_entry_override(entry, CPUID_8000_000A_EDX);
+ break;
+ case 0x80000019:
+ entry->ecx = entry->edx = 0;
+ break;
+ case 0x8000001a:
+ entry->eax &= GENMASK(2, 0);
+ entry->ebx = entry->ecx = entry->edx = 0;
+ break;
+ case 0x8000001e:
+ /* Do not return host topology information. */
+ entry->eax = entry->ebx = entry->ecx = 0;
+ entry->edx = 0; /* reserved */
+ break;
+ /* Support memory encryption cpuid if host supports it */
+ case 0x8000001F:
+ if (!boot_cpu_has(X86_FEATURE_SEV))
+ entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
+ 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:
+ cpuid_entry_override(entry, 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;
+ }
+
+ r = 0;
+
+out:
+ put_cpu();
+
+ return r;
+}
+
+static int do_cpuid_func(struct kvm_cpuid_array *array, u32 func,
+ unsigned int type)
+{
+ if (type == KVM_GET_EMULATED_CPUID)
+ return __do_cpuid_func_emulated(array, func);
+
+ return __do_cpuid_func(array, func);
+}
+
+#define CENTAUR_CPUID_SIGNATURE 0xC0000000
+
+static int get_cpuid_func(struct kvm_cpuid_array *array, u32 func,
+ unsigned int type)
+{
+ u32 limit;
+ int r;
+
+ if (func == CENTAUR_CPUID_SIGNATURE &&
+ boot_cpu_data.x86_vendor != X86_VENDOR_CENTAUR)
+ return 0;
+
+ r = do_cpuid_func(array, func, type);
+ if (r)
+ return r;
+
+ limit = array->entries[array->nent - 1].eax;
+ for (func = func + 1; func <= limit; ++func) {
+ r = do_cpuid_func(array, func, type);
+ if (r)
+ break;
+ }
+
+ return r;
+}
+
+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)
+{
+ static const u32 funcs[] = {
+ 0, 0x80000000, CENTAUR_CPUID_SIGNATURE, KVM_CPUID_SIGNATURE,
+ };
+
+ struct kvm_cpuid_array array = {
+ .nent = 0,
+ };
+ int r, i;
+
+ if (cpuid->nent < 1)
+ return -E2BIG;
+ if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
+ cpuid->nent = KVM_MAX_CPUID_ENTRIES;
+
+ if (sanity_check_entries(entries, cpuid->nent, type))
+ return -EINVAL;
+
+ array.entries = vzalloc(array_size(sizeof(struct kvm_cpuid_entry2),
+ cpuid->nent));
+ if (!array.entries)
+ return -ENOMEM;
+
+ array.maxnent = cpuid->nent;
+
+ for (i = 0; i < ARRAY_SIZE(funcs); i++) {
+ r = get_cpuid_func(&array, funcs[i], type);
+ if (r)
+ goto out_free;
+ }
+ cpuid->nent = array.nent;
+
+ if (copy_to_user(entries, array.entries,
+ array.nent * sizeof(struct kvm_cpuid_entry2)))
+ r = -EFAULT;
+
+out_free:
+ vfree(array.entries);
+ return r;
+}
+
+struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
+ u32 function, u32 index)
+{
+ return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent,
+ function, index);
+}
+EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
+
+/*
+ * Intel CPUID semantics treats any query for an out-of-range leaf as if the
+ * highest basic leaf (i.e. CPUID.0H:EAX) were requested. AMD CPUID semantics
+ * returns all zeroes for any undefined leaf, whether or not the leaf is in
+ * range. Centaur/VIA follows Intel semantics.
+ *
+ * A leaf is considered out-of-range if its function is higher than the maximum
+ * supported leaf of its associated class or if its associated class does not
+ * exist.
+ *
+ * There are three primary classes to be considered, with their respective
+ * ranges described as "<base> - <top>[,<base2> - <top2>] inclusive. A primary
+ * class exists if a guest CPUID entry for its <base> leaf exists. For a given
+ * class, CPUID.<base>.EAX contains the max supported leaf for the class.
+ *
+ * - Basic: 0x00000000 - 0x3fffffff, 0x50000000 - 0x7fffffff
+ * - Hypervisor: 0x40000000 - 0x4fffffff
+ * - Extended: 0x80000000 - 0xbfffffff
+ * - Centaur: 0xc0000000 - 0xcfffffff
+ *
+ * The Hypervisor class is further subdivided into sub-classes that each act as
+ * their own indepdent class associated with a 0x100 byte range. E.g. if Qemu
+ * is advertising support for both HyperV and KVM, the resulting Hypervisor
+ * CPUID sub-classes are:
+ *
+ * - HyperV: 0x40000000 - 0x400000ff
+ * - KVM: 0x40000100 - 0x400001ff
+ */
+static struct kvm_cpuid_entry2 *
+get_out_of_range_cpuid_entry(struct kvm_vcpu *vcpu, u32 *fn_ptr, u32 index)
+{
+ struct kvm_cpuid_entry2 *basic, *class;
+ u32 function = *fn_ptr;
+
+ basic = kvm_find_cpuid_entry(vcpu, 0, 0);
+ if (!basic)
+ return NULL;
+
+ if (is_guest_vendor_amd(basic->ebx, basic->ecx, basic->edx) ||
+ is_guest_vendor_hygon(basic->ebx, basic->ecx, basic->edx))
+ return NULL;
+
+ if (function >= 0x40000000 && function <= 0x4fffffff)
+ class = kvm_find_cpuid_entry(vcpu, function & 0xffffff00, 0);
+ else if (function >= 0xc0000000)
+ class = kvm_find_cpuid_entry(vcpu, 0xc0000000, 0);
+ else
+ class = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
+
+ if (class && function <= class->eax)
+ return NULL;
+
+ /*
+ * Leaf specific adjustments are also applied when redirecting to the
+ * max basic entry, e.g. if the max basic leaf is 0xb but there is no
+ * entry for CPUID.0xb.index (see below), then the output value for EDX
+ * needs to be pulled from CPUID.0xb.1.
+ */
+ *fn_ptr = basic->eax;
+
+ /*
+ * The class does not exist or the requested function is out of range;
+ * the effective CPUID entry is the max basic leaf. Note, the index of
+ * the original requested leaf is observed!
+ */
+ return kvm_find_cpuid_entry(vcpu, basic->eax, index);
+}
+
+bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
+ u32 *ecx, u32 *edx, bool exact_only)
+{
+ u32 orig_function = *eax, function = *eax, index = *ecx;
+ struct kvm_cpuid_entry2 *entry;
+ bool exact, used_max_basic = false;
+
+ entry = kvm_find_cpuid_entry(vcpu, function, index);
+ exact = !!entry;
+
+ if (!entry && !exact_only) {
+ entry = get_out_of_range_cpuid_entry(vcpu, &function, index);
+ used_max_basic = !!entry;
+ }
+
+ if (entry) {
+ *eax = entry->eax;
+ *ebx = entry->ebx;
+ *ecx = entry->ecx;
+ *edx = entry->edx;
+ if (function == 7 && index == 0) {
+ u64 data;
+ if (!__kvm_get_msr(vcpu, MSR_IA32_TSX_CTRL, &data, true) &&
+ (data & TSX_CTRL_CPUID_CLEAR))
+ *ebx &= ~(F(RTM) | F(HLE));
+ }
+ } else {
+ *eax = *ebx = *ecx = *edx = 0;
+ /*
+ * When leaf 0BH or 1FH is defined, CL is pass-through
+ * and EDX is always the x2APIC ID, even for undefined
+ * subleaves. Index 1 will exist iff the leaf is
+ * implemented, so we pass through CL iff leaf 1
+ * exists. EDX can be copied from any existing index.
+ */
+ if (function == 0xb || function == 0x1f) {
+ entry = kvm_find_cpuid_entry(vcpu, function, 1);
+ if (entry) {
+ *ecx = index & 0xff;
+ *edx = entry->edx;
+ }
+ }
+ }
+ trace_kvm_cpuid(orig_function, index, *eax, *ebx, *ecx, *edx, exact,
+ used_max_basic);
+ return exact;
+}
+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_rax_read(vcpu);
+ ecx = kvm_rcx_read(vcpu);
+ kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, false);
+ kvm_rax_write(vcpu, eax);
+ kvm_rbx_write(vcpu, ebx);
+ kvm_rcx_write(vcpu, ecx);
+ kvm_rdx_write(vcpu, edx);
+ return kvm_skip_emulated_instruction(vcpu);
+}
+EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);