diff options
Diffstat (limited to 'arch/x86/kvm/cpuid.h')
| -rw-r--r-- | arch/x86/kvm/cpuid.h | 294 |
1 files changed, 180 insertions, 114 deletions
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index da6728383052..d3f5ae15a7ca 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -1,13 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ #ifndef ARCH_X86_KVM_CPUID_H #define ARCH_X86_KVM_CPUID_H -#include "x86.h" +#include "reverse_cpuid.h" #include <asm/cpu.h> +#include <asm/processor.h> +#include <uapi/asm/kvm_para.h> + +extern u32 kvm_cpu_caps[NR_KVM_CPU_CAPS] __read_mostly; +void kvm_set_cpu_caps(void); + +void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu); +struct kvm_cpuid_entry2 *kvm_find_cpuid_entry2(struct kvm_cpuid_entry2 *entries, + int nent, u32 function, u64 index); +/* + * Magic value used by KVM when querying userspace-provided CPUID entries and + * doesn't care about the CPIUD index because the index of the function in + * question is not significant. Note, this magic value must have at least one + * bit set in bits[63:32] and must be consumed as a u64 by kvm_find_cpuid_entry2() + * to avoid false positives when processing guest CPUID input. + * + * KVM_CPUID_INDEX_NOT_SIGNIFICANT should never be used directly outside of + * kvm_find_cpuid_entry2() and kvm_find_cpuid_entry(). + */ +#define KVM_CPUID_INDEX_NOT_SIGNIFICANT -1ull + +static inline struct kvm_cpuid_entry2 *kvm_find_cpuid_entry_index(struct kvm_vcpu *vcpu, + u32 function, u32 index) +{ + return kvm_find_cpuid_entry2(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent, + function, index); +} + +static inline struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, + u32 function) +{ + return kvm_find_cpuid_entry2(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent, + function, KVM_CPUID_INDEX_NOT_SIGNIFICANT); +} -int kvm_update_cpuid(struct kvm_vcpu *vcpu); -bool kvm_mpx_supported(void); -struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, - u32 function, u32 index); int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, struct kvm_cpuid_entry2 __user *entries, unsigned int type); @@ -20,208 +51,243 @@ int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, struct kvm_cpuid_entry2 __user *entries); -void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx); +bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, + u32 *ecx, u32 *edx, bool exact_only); + +void __init kvm_init_xstate_sizes(void); +u32 xstate_required_size(u64 xstate_bv, bool compacted); int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu); +int cpuid_query_maxguestphyaddr(struct kvm_vcpu *vcpu); +u64 kvm_vcpu_reserved_gpa_bits_raw(struct kvm_vcpu *vcpu); static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu) { return vcpu->arch.maxphyaddr; } -static inline bool guest_cpuid_has_xsave(struct kvm_vcpu *vcpu) +static inline bool kvm_vcpu_is_legal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa) { - struct kvm_cpuid_entry2 *best; - - if (!static_cpu_has(X86_FEATURE_XSAVE)) - return false; - - best = kvm_find_cpuid_entry(vcpu, 1, 0); - return best && (best->ecx & bit(X86_FEATURE_XSAVE)); + return !(gpa & vcpu->arch.reserved_gpa_bits); } -static inline bool guest_cpuid_has_mtrr(struct kvm_vcpu *vcpu) +static inline bool kvm_vcpu_is_legal_aligned_gpa(struct kvm_vcpu *vcpu, + gpa_t gpa, gpa_t alignment) { - struct kvm_cpuid_entry2 *best; - - best = kvm_find_cpuid_entry(vcpu, 1, 0); - return best && (best->edx & bit(X86_FEATURE_MTRR)); + return IS_ALIGNED(gpa, alignment) && kvm_vcpu_is_legal_gpa(vcpu, gpa); } -static inline bool guest_cpuid_has_tsc_adjust(struct kvm_vcpu *vcpu) +static inline bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa) { - struct kvm_cpuid_entry2 *best; - - best = kvm_find_cpuid_entry(vcpu, 7, 0); - return best && (best->ebx & bit(X86_FEATURE_TSC_ADJUST)); + return kvm_vcpu_is_legal_aligned_gpa(vcpu, gpa, PAGE_SIZE); } -static inline bool guest_cpuid_has_smep(struct kvm_vcpu *vcpu) +static __always_inline void cpuid_entry_override(struct kvm_cpuid_entry2 *entry, + unsigned int leaf) { - struct kvm_cpuid_entry2 *best; + u32 *reg = cpuid_entry_get_reg(entry, leaf * 32); - best = kvm_find_cpuid_entry(vcpu, 7, 0); - return best && (best->ebx & bit(X86_FEATURE_SMEP)); + BUILD_BUG_ON(leaf >= ARRAY_SIZE(kvm_cpu_caps)); + *reg = kvm_cpu_caps[leaf]; } -static inline bool guest_cpuid_has_smap(struct kvm_vcpu *vcpu) +static __always_inline bool guest_cpuid_has(struct kvm_vcpu *vcpu, + unsigned int x86_feature) { - struct kvm_cpuid_entry2 *best; + const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature); + struct kvm_cpuid_entry2 *entry; + u32 *reg; + + /* + * XSAVES is a special snowflake. Due to lack of a dedicated intercept + * on SVM, KVM must assume that XSAVES (and thus XRSTORS) is usable by + * the guest if the host supports XSAVES and *XSAVE* is exposed to the + * guest. Because the guest can execute XSAVES and XRSTORS, i.e. can + * indirectly consume XSS, KVM must ensure XSS is zeroed when running + * the guest, i.e. must set XSAVES in vCPU capabilities. But to reject + * direct XSS reads and writes (to minimize the virtualization hole and + * honor userspace's CPUID), KVM needs to check the raw guest CPUID, + * not KVM's view of guest capabilities. + * + * For all other features, guest capabilities are accurate. Expand + * this allowlist with extreme vigilance. + */ + BUILD_BUG_ON(x86_feature != X86_FEATURE_XSAVES); - best = kvm_find_cpuid_entry(vcpu, 7, 0); - return best && (best->ebx & bit(X86_FEATURE_SMAP)); + entry = kvm_find_cpuid_entry_index(vcpu, cpuid.function, cpuid.index); + if (!entry) + return NULL; + + reg = __cpuid_entry_get_reg(entry, cpuid.reg); + if (!reg) + return false; + + return *reg & __feature_bit(x86_feature); } -static inline bool guest_cpuid_has_fsgsbase(struct kvm_vcpu *vcpu) +static inline bool guest_cpuid_is_amd_compatible(struct kvm_vcpu *vcpu) { - struct kvm_cpuid_entry2 *best; + return vcpu->arch.is_amd_compatible; +} - best = kvm_find_cpuid_entry(vcpu, 7, 0); - return best && (best->ebx & bit(X86_FEATURE_FSGSBASE)); +static inline bool guest_cpuid_is_intel_compatible(struct kvm_vcpu *vcpu) +{ + return !guest_cpuid_is_amd_compatible(vcpu); } -static inline bool guest_cpuid_has_pku(struct kvm_vcpu *vcpu) +static inline int guest_cpuid_family(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *best; - best = kvm_find_cpuid_entry(vcpu, 7, 0); - return best && (best->ecx & bit(X86_FEATURE_PKU)); + best = kvm_find_cpuid_entry(vcpu, 0x1); + if (!best) + return -1; + + return x86_family(best->eax); } -static inline bool guest_cpuid_has_longmode(struct kvm_vcpu *vcpu) +static inline int guest_cpuid_model(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *best; - best = kvm_find_cpuid_entry(vcpu, 0x80000001, 0); - return best && (best->edx & bit(X86_FEATURE_LM)); + best = kvm_find_cpuid_entry(vcpu, 0x1); + if (!best) + return -1; + + return x86_model(best->eax); } -static inline bool guest_cpuid_has_osvw(struct kvm_vcpu *vcpu) +static inline bool cpuid_model_is_consistent(struct kvm_vcpu *vcpu) { - struct kvm_cpuid_entry2 *best; - - best = kvm_find_cpuid_entry(vcpu, 0x80000001, 0); - return best && (best->ecx & bit(X86_FEATURE_OSVW)); + return boot_cpu_data.x86_model == guest_cpuid_model(vcpu); } -static inline bool guest_cpuid_has_pcid(struct kvm_vcpu *vcpu) +static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu) { struct kvm_cpuid_entry2 *best; - best = kvm_find_cpuid_entry(vcpu, 1, 0); - return best && (best->ecx & bit(X86_FEATURE_PCID)); + best = kvm_find_cpuid_entry(vcpu, 0x1); + if (!best) + return -1; + + return x86_stepping(best->eax); } -static inline bool guest_cpuid_has_x2apic(struct kvm_vcpu *vcpu) +static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu) { - struct kvm_cpuid_entry2 *best; + return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT; +} - best = kvm_find_cpuid_entry(vcpu, 1, 0); - return best && (best->ecx & bit(X86_FEATURE_X2APIC)); +static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu) +{ + return vcpu->arch.msr_misc_features_enables & + MSR_MISC_FEATURES_ENABLES_CPUID_FAULT; } -static inline bool guest_cpuid_is_amd(struct kvm_vcpu *vcpu) +static __always_inline void kvm_cpu_cap_clear(unsigned int x86_feature) { - struct kvm_cpuid_entry2 *best; + unsigned int x86_leaf = __feature_leaf(x86_feature); - best = kvm_find_cpuid_entry(vcpu, 0, 0); - return best && best->ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx; + kvm_cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature); } -static inline bool guest_cpuid_has_gbpages(struct kvm_vcpu *vcpu) +static __always_inline void kvm_cpu_cap_set(unsigned int x86_feature) { - struct kvm_cpuid_entry2 *best; + unsigned int x86_leaf = __feature_leaf(x86_feature); - best = kvm_find_cpuid_entry(vcpu, 0x80000001, 0); - return best && (best->edx & bit(X86_FEATURE_GBPAGES)); + kvm_cpu_caps[x86_leaf] |= __feature_bit(x86_feature); } -static inline bool guest_cpuid_has_rtm(struct kvm_vcpu *vcpu) +static __always_inline u32 kvm_cpu_cap_get(unsigned int x86_feature) { - struct kvm_cpuid_entry2 *best; + unsigned int x86_leaf = __feature_leaf(x86_feature); - best = kvm_find_cpuid_entry(vcpu, 7, 0); - return best && (best->ebx & bit(X86_FEATURE_RTM)); + return kvm_cpu_caps[x86_leaf] & __feature_bit(x86_feature); } -static inline bool guest_cpuid_has_mpx(struct kvm_vcpu *vcpu) +static __always_inline bool kvm_cpu_cap_has(unsigned int x86_feature) { - struct kvm_cpuid_entry2 *best; + return !!kvm_cpu_cap_get(x86_feature); +} - best = kvm_find_cpuid_entry(vcpu, 7, 0); - return best && (best->ebx & bit(X86_FEATURE_MPX)); +static __always_inline void kvm_cpu_cap_check_and_set(unsigned int x86_feature) +{ + if (boot_cpu_has(x86_feature)) + kvm_cpu_cap_set(x86_feature); } -static inline bool guest_cpuid_has_rdtscp(struct kvm_vcpu *vcpu) +static __always_inline bool guest_pv_has(struct kvm_vcpu *vcpu, + unsigned int kvm_feature) { - struct kvm_cpuid_entry2 *best; + if (!vcpu->arch.pv_cpuid.enforce) + return true; - best = kvm_find_cpuid_entry(vcpu, 0x80000001, 0); - return best && (best->edx & bit(X86_FEATURE_RDTSCP)); + return vcpu->arch.pv_cpuid.features & (1u << kvm_feature); } -/* - * NRIPS is provided through cpuidfn 0x8000000a.edx bit 3 - */ -#define BIT_NRIPS 3 - -static inline bool guest_cpuid_has_nrips(struct kvm_vcpu *vcpu) +static __always_inline void guest_cpu_cap_set(struct kvm_vcpu *vcpu, + unsigned int x86_feature) { - struct kvm_cpuid_entry2 *best; - - best = kvm_find_cpuid_entry(vcpu, 0x8000000a, 0); + unsigned int x86_leaf = __feature_leaf(x86_feature); - /* - * NRIPS is a scattered cpuid feature, so we can't use - * X86_FEATURE_NRIPS here (X86_FEATURE_NRIPS would be bit - * position 8, not 3). - */ - return best && (best->edx & bit(BIT_NRIPS)); + vcpu->arch.cpu_caps[x86_leaf] |= __feature_bit(x86_feature); } -#undef BIT_NRIPS -static inline int guest_cpuid_family(struct kvm_vcpu *vcpu) +static __always_inline void guest_cpu_cap_clear(struct kvm_vcpu *vcpu, + unsigned int x86_feature) { - struct kvm_cpuid_entry2 *best; + unsigned int x86_leaf = __feature_leaf(x86_feature); - best = kvm_find_cpuid_entry(vcpu, 0x1, 0); - if (!best) - return -1; + vcpu->arch.cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature); +} - return x86_family(best->eax); +static __always_inline void guest_cpu_cap_change(struct kvm_vcpu *vcpu, + unsigned int x86_feature, + bool guest_has_cap) +{ + if (guest_has_cap) + guest_cpu_cap_set(vcpu, x86_feature); + else + guest_cpu_cap_clear(vcpu, x86_feature); } -static inline int guest_cpuid_model(struct kvm_vcpu *vcpu) +static __always_inline bool guest_cpu_cap_has(struct kvm_vcpu *vcpu, + unsigned int x86_feature) { - struct kvm_cpuid_entry2 *best; + unsigned int x86_leaf = __feature_leaf(x86_feature); - best = kvm_find_cpuid_entry(vcpu, 0x1, 0); - if (!best) - return -1; + /* + * Except for MWAIT, querying dynamic feature bits is disallowed, so + * that KVM can defer runtime updates until the next CPUID emulation. + */ + BUILD_BUG_ON(x86_feature == X86_FEATURE_APIC || + x86_feature == X86_FEATURE_OSXSAVE || + x86_feature == X86_FEATURE_OSPKE); - return x86_model(best->eax); + return vcpu->arch.cpu_caps[x86_leaf] & __feature_bit(x86_feature); } -static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu) +static inline bool kvm_vcpu_is_legal_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) { - struct kvm_cpuid_entry2 *best; - - best = kvm_find_cpuid_entry(vcpu, 0x1, 0); - if (!best) - return -1; + if (guest_cpu_cap_has(vcpu, X86_FEATURE_LAM)) + cr3 &= ~(X86_CR3_LAM_U48 | X86_CR3_LAM_U57); - return x86_stepping(best->eax); + return kvm_vcpu_is_legal_gpa(vcpu, cr3); } -static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu) +static inline bool guest_has_spec_ctrl_msr(struct kvm_vcpu *vcpu) { - return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT; + return (guest_cpu_cap_has(vcpu, X86_FEATURE_SPEC_CTRL) || + guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_STIBP) || + guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_IBRS) || + guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_SSBD)); } -static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu) +static inline bool guest_has_pred_cmd_msr(struct kvm_vcpu *vcpu) { - return vcpu->arch.msr_misc_features_enables & - MSR_MISC_FEATURES_ENABLES_CPUID_FAULT; + return (guest_cpu_cap_has(vcpu, X86_FEATURE_SPEC_CTRL) || + guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_IBPB) || + guest_cpu_cap_has(vcpu, X86_FEATURE_SBPB)); } #endif |