From 66a6950f99950c77e2898e48d668eca1dac10a1e Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Mon, 2 Mar 2020 15:56:41 -0800 Subject: [PATCH] KVM: x86: Introduce kvm_cpu_caps to replace runtime CPUID masking Calculate the CPUID masks for KVM_GET_SUPPORTED_CPUID at load time using what is effectively a KVM-adjusted copy of boot_cpu_data, or more precisely, the x86_capability array in boot_cpu_data. In terms of KVM support, the vast majority of CPUID feature bits are constant, and *all* feature support is known at KVM load time. Rather than apply boot_cpu_data, which is effectively read-only after init, at runtime, copy it into a KVM-specific array and use *that* to mask CPUID registers. In additional to consolidating the masking, kvm_cpu_caps can be adjusted by SVM/VMX at load time and thus eliminate all feature bit manipulation in ->set_supported_cpuid(). Opportunistically clean up a few warts: - Replace bare "unsigned" with "unsigned int" when a feature flag is captured in a local variable, e.g. f_nx. - Sort the CPUID masks by function, index and register (alphabetically for registers, i.e. EBX comes before ECX/EDX). - Remove the superfluous /* cpuid 7.0.ecx */ comments. No functional change intended. Signed-off-by: Sean Christopherson [Call kvm_set_cpu_caps from kvm_x86_ops->hardware_setup due to fixed GBPAGES patch. - Paolo] Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.c | 233 ++++++++++++++++++++++++++----------------------- arch/x86/kvm/cpuid.h | 22 ++++- arch/x86/kvm/svm.c | 2 + arch/x86/kvm/vmx/vmx.c | 2 + 4 files changed, 151 insertions(+), 108 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 3e4b03c8ec12..31ea934d9b49 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -24,6 +24,13 @@ #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; @@ -254,6 +261,123 @@ out: return r; } +static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask) +{ + reverse_cpuid_check(leaf); + kvm_cpu_caps[leaf] &= mask; +} + +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, 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_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) | 0 /*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); + + 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) + ); + + 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) + ); + + 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; const int maxnent; @@ -331,48 +455,13 @@ static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func) static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry) { - unsigned f_la57; - - /* 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) | 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*/; - - /* cpuid 7.0.ecx*/ - const u32 kvm_cpuid_7_0_ecx_x86_features = - F(AVX512VBMI) | F(LA57) | 0 /*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*/; - - /* 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) | F(INTEL_STIBP) | - F(MD_CLEAR); - - /* cpuid 7.1.eax */ - const u32 kvm_cpuid_7_1_eax_x86_features = - F(AVX512_BF16); - switch (entry->index) { case 0: entry->eax = min(entry->eax, 1u); - entry->ebx &= kvm_cpuid_7_0_ebx_x86_features; cpuid_entry_mask(entry, CPUID_7_0_EBX); /* TSC_ADJUST is emulated */ cpuid_entry_set(entry, X86_FEATURE_TSC_ADJUST); - - entry->ecx &= kvm_cpuid_7_0_ecx_x86_features; - f_la57 = cpuid_entry_get(entry, X86_FEATURE_LA57); cpuid_entry_mask(entry, CPUID_7_ECX); - /* Set LA57 based on hardware capability. */ - entry->ecx |= f_la57; - - entry->edx &= kvm_cpuid_7_0_edx_x86_features; cpuid_entry_mask(entry, CPUID_7_EDX); if (boot_cpu_has(X86_FEATURE_IBPB) && boot_cpu_has(X86_FEATURE_IBRS)) cpuid_entry_set(entry, X86_FEATURE_SPEC_CTRL); @@ -387,7 +476,7 @@ static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry) cpuid_entry_set(entry, X86_FEATURE_ARCH_CAPABILITIES); break; case 1: - entry->eax &= kvm_cpuid_7_1_eax_x86_features; + cpuid_entry_mask(entry, CPUID_7_1_EAX); entry->ebx = 0; entry->ecx = 0; entry->edx = 0; @@ -406,72 +495,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) { struct kvm_cpuid_entry2 *entry; int r, i, max_idx; - unsigned f_nx = is_efer_nx() ? F(NX) : 0; -#ifdef CONFIG_X86_64 - unsigned f_gbpages = F(GBPAGES); - unsigned f_lm = F(LM); -#else - unsigned f_gbpages = 0; - unsigned f_lm = 0; -#endif unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 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) | - F(TOPOEXT) | F(PERFCTR_CORE); - - /* cpuid 0x80000008.ebx */ - const u32 kvm_cpuid_8000_0008_ebx_x86_features = - 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); - - /* 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 0xD.1.eax */ - const u32 kvm_cpuid_D_1_eax_x86_features = - F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | F(XSAVES); - /* all calls to cpuid_count() should be made on the same cpu */ get_cpu(); @@ -487,9 +512,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) entry->eax = min(entry->eax, 0x1fU); break; case 1: - entry->edx &= kvm_cpuid_1_edx_x86_features; cpuid_entry_mask(entry, CPUID_1_EDX); - entry->ecx &= kvm_cpuid_1_ecx_x86_features; cpuid_entry_mask(entry, CPUID_1_ECX); /* we support x2apic emulation even if host does not support * it since we emulate x2apic in software */ @@ -599,7 +622,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) if (!entry) goto out; - entry->eax &= kvm_cpuid_D_1_eax_x86_features; cpuid_entry_mask(entry, CPUID_D_1_EAX); if (!kvm_x86_ops->xsaves_supported()) @@ -683,11 +705,10 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) entry->eax = min(entry->eax, 0x8000001f); break; case 0x80000001: - entry->edx &= kvm_cpuid_8000_0001_edx_x86_features; cpuid_entry_mask(entry, CPUID_8000_0001_EDX); + /* Add it manually because it may not be in host CPUID. */ if (!tdp_enabled) cpuid_entry_set(entry, X86_FEATURE_GBPAGES); - entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features; cpuid_entry_mask(entry, CPUID_8000_0001_ECX); break; case 0x80000007: /* Advanced power management */ @@ -706,7 +727,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) g_phys_as = phys_as; entry->eax = g_phys_as | (virt_as << 8); entry->edx = 0; - entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features; cpuid_entry_mask(entry, CPUID_8000_0008_EBX); /* * AMD has separate bits for each SPEC_CTRL bit. @@ -749,7 +769,6 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) entry->eax = min(entry->eax, 0xC0000004); break; case 0xC0000001: - entry->edx &= kvm_cpuid_C000_0001_edx_x86_features; cpuid_entry_mask(entry, CPUID_C000_0001_EDX); break; case 3: /* Processor serial number */ diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index 407dc26c0633..13374f885c81 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -6,6 +6,9 @@ #include #include +extern u32 kvm_cpu_caps[NCAPINTS] __read_mostly; +void kvm_set_cpu_caps(void); + int kvm_update_cpuid(struct kvm_vcpu *vcpu); struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, u32 function, u32 index); @@ -172,7 +175,8 @@ static __always_inline void cpuid_entry_mask(struct kvm_cpuid_entry2 *entry, { u32 *reg = cpuid_entry_get_reg(entry, leaf * 32); - *reg &= boot_cpu_data.x86_capability[leaf]; + BUILD_BUG_ON(leaf >= ARRAY_SIZE(kvm_cpu_caps)); + *reg &= kvm_cpu_caps[leaf]; } static __always_inline u32 *guest_cpuid_get_register(struct kvm_vcpu *vcpu, @@ -262,4 +266,20 @@ static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu) MSR_MISC_FEATURES_ENABLES_CPUID_FAULT; } +static __always_inline void kvm_cpu_cap_clear(unsigned int x86_feature) +{ + unsigned int x86_leaf = x86_feature / 32; + + reverse_cpuid_check(x86_leaf); + kvm_cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature); +} + +static __always_inline void kvm_cpu_cap_set(unsigned int x86_feature) +{ + unsigned int x86_leaf = x86_feature / 32; + + reverse_cpuid_check(x86_leaf); + kvm_cpu_caps[x86_leaf] |= __feature_bit(x86_feature); +} + #endif diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 8984ae140689..aae5e3eff48d 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1479,6 +1479,8 @@ static __init int svm_hardware_setup(void) pr_info("Virtual GIF supported\n"); } + kvm_set_cpu_caps(); + return 0; err: diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index bf27cb8ac3fc..ae482f4f5678 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7818,6 +7818,8 @@ static __init int hardware_setup(void) return r; } + kvm_set_cpu_caps(); + r = alloc_kvm_area(); if (r) nested_vmx_hardware_unsetup(); -- 2.11.0