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author | Ricardo Koller <ricarkol@google.com> | 2021-04-21 17:56:22 -0700 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-04-26 05:27:13 -0400 |
commit | 013380782d4d675d4f8d9891ca7d010795152dc8 (patch) | |
tree | b25d7820dfc8f2fbc2c5b6582c8514a723cd9935 | |
parent | 27b4a9c4549c085d355cec5dc566f7ae58639f71 (diff) | |
download | linux-013380782d4d675d4f8d9891ca7d010795152dc8.tar.gz linux-013380782d4d675d4f8d9891ca7d010795152dc8.tar.bz2 linux-013380782d4d675d4f8d9891ca7d010795152dc8.zip |
KVM: x86: Move reverse CPUID helpers to separate header file
Split out the reverse CPUID machinery to a dedicated header file
so that KVM selftests can reuse the reverse CPUID definitions without
introducing any '#ifdef __KERNEL__' pollution.
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Message-Id: <20210422005626.564163-2-ricarkol@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r-- | arch/x86/kvm/cpuid.h | 177 | ||||
-rw-r--r-- | arch/x86/kvm/reverse_cpuid.h | 185 |
2 files changed, 186 insertions, 176 deletions
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index 50c78dcf9215..c99edfff7f82 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -3,28 +3,11 @@ #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> -/* - * Hardware-defined CPUID leafs that are scattered in the kernel, but need to - * be directly used by KVM. Note, these word values conflict with the kernel's - * "bug" caps, but KVM doesn't use those. - */ -enum kvm_only_cpuid_leafs { - CPUID_12_EAX = NCAPINTS, - NR_KVM_CPU_CAPS, - - NKVMCAPINTS = NR_KVM_CPU_CAPS - NCAPINTS, -}; - -#define KVM_X86_FEATURE(w, f) ((w)*32 + (f)) - -/* Intel-defined SGX sub-features, CPUID level 0x12 (EAX). */ -#define KVM_X86_FEATURE_SGX1 KVM_X86_FEATURE(CPUID_12_EAX, 0) -#define KVM_X86_FEATURE_SGX2 KVM_X86_FEATURE(CPUID_12_EAX, 1) - extern u32 kvm_cpu_caps[NR_KVM_CPU_CAPS] __read_mostly; void kvm_set_cpu_caps(void); @@ -76,164 +59,6 @@ static inline bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa) return kvm_vcpu_is_legal_aligned_gpa(vcpu, gpa, PAGE_SIZE); } -struct cpuid_reg { - u32 function; - u32 index; - int reg; -}; - -static const struct cpuid_reg reverse_cpuid[] = { - [CPUID_1_EDX] = { 1, 0, CPUID_EDX}, - [CPUID_8000_0001_EDX] = {0x80000001, 0, CPUID_EDX}, - [CPUID_8086_0001_EDX] = {0x80860001, 0, CPUID_EDX}, - [CPUID_1_ECX] = { 1, 0, CPUID_ECX}, - [CPUID_C000_0001_EDX] = {0xc0000001, 0, CPUID_EDX}, - [CPUID_8000_0001_ECX] = {0x80000001, 0, CPUID_ECX}, - [CPUID_7_0_EBX] = { 7, 0, CPUID_EBX}, - [CPUID_D_1_EAX] = { 0xd, 1, CPUID_EAX}, - [CPUID_8000_0008_EBX] = {0x80000008, 0, CPUID_EBX}, - [CPUID_6_EAX] = { 6, 0, CPUID_EAX}, - [CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX}, - [CPUID_7_ECX] = { 7, 0, CPUID_ECX}, - [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX}, - [CPUID_7_EDX] = { 7, 0, CPUID_EDX}, - [CPUID_7_1_EAX] = { 7, 1, CPUID_EAX}, - [CPUID_12_EAX] = {0x00000012, 0, CPUID_EAX}, -}; - -/* - * Reverse CPUID and its derivatives can only be used for hardware-defined - * feature words, i.e. words whose bits directly correspond to a CPUID leaf. - * Retrieving a feature bit or masking guest CPUID from a Linux-defined word - * is nonsensical as the bit number/mask is an arbitrary software-defined value - * and can't be used by KVM to query/control guest capabilities. And obviously - * the leaf being queried must have an entry in the lookup table. - */ -static __always_inline void reverse_cpuid_check(unsigned int x86_leaf) -{ - BUILD_BUG_ON(x86_leaf == CPUID_LNX_1); - BUILD_BUG_ON(x86_leaf == CPUID_LNX_2); - BUILD_BUG_ON(x86_leaf == CPUID_LNX_3); - BUILD_BUG_ON(x86_leaf == CPUID_LNX_4); - BUILD_BUG_ON(x86_leaf >= ARRAY_SIZE(reverse_cpuid)); - BUILD_BUG_ON(reverse_cpuid[x86_leaf].function == 0); -} - -/* - * Translate feature bits that are scattered in the kernel's cpufeatures word - * into KVM feature words that align with hardware's definitions. - */ -static __always_inline u32 __feature_translate(int x86_feature) -{ - if (x86_feature == X86_FEATURE_SGX1) - return KVM_X86_FEATURE_SGX1; - else if (x86_feature == X86_FEATURE_SGX2) - return KVM_X86_FEATURE_SGX2; - - return x86_feature; -} - -static __always_inline u32 __feature_leaf(int x86_feature) -{ - return __feature_translate(x86_feature) / 32; -} - -/* - * Retrieve the bit mask from an X86_FEATURE_* definition. Features contain - * the hardware defined bit number (stored in bits 4:0) and a software defined - * "word" (stored in bits 31:5). The word is used to index into arrays of - * bit masks that hold the per-cpu feature capabilities, e.g. this_cpu_has(). - */ -static __always_inline u32 __feature_bit(int x86_feature) -{ - x86_feature = __feature_translate(x86_feature); - - reverse_cpuid_check(x86_feature / 32); - return 1 << (x86_feature & 31); -} - -#define feature_bit(name) __feature_bit(X86_FEATURE_##name) - -static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned int x86_feature) -{ - unsigned int x86_leaf = __feature_leaf(x86_feature); - - reverse_cpuid_check(x86_leaf); - return reverse_cpuid[x86_leaf]; -} - -static __always_inline u32 *__cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry, - u32 reg) -{ - switch (reg) { - case CPUID_EAX: - return &entry->eax; - case CPUID_EBX: - return &entry->ebx; - case CPUID_ECX: - return &entry->ecx; - case CPUID_EDX: - return &entry->edx; - default: - BUILD_BUG(); - return NULL; - } -} - -static __always_inline u32 *cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry, - unsigned int x86_feature) -{ - const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature); - - return __cpuid_entry_get_reg(entry, cpuid.reg); -} - -static __always_inline u32 cpuid_entry_get(struct kvm_cpuid_entry2 *entry, - unsigned int x86_feature) -{ - u32 *reg = cpuid_entry_get_reg(entry, x86_feature); - - return *reg & __feature_bit(x86_feature); -} - -static __always_inline bool cpuid_entry_has(struct kvm_cpuid_entry2 *entry, - unsigned int x86_feature) -{ - return cpuid_entry_get(entry, x86_feature); -} - -static __always_inline void cpuid_entry_clear(struct kvm_cpuid_entry2 *entry, - unsigned int x86_feature) -{ - u32 *reg = cpuid_entry_get_reg(entry, x86_feature); - - *reg &= ~__feature_bit(x86_feature); -} - -static __always_inline void cpuid_entry_set(struct kvm_cpuid_entry2 *entry, - unsigned int x86_feature) -{ - u32 *reg = cpuid_entry_get_reg(entry, x86_feature); - - *reg |= __feature_bit(x86_feature); -} - -static __always_inline void cpuid_entry_change(struct kvm_cpuid_entry2 *entry, - unsigned int x86_feature, - bool set) -{ - u32 *reg = cpuid_entry_get_reg(entry, x86_feature); - - /* - * Open coded instead of using cpuid_entry_{clear,set}() to coerce the - * compiler into using CMOV instead of Jcc when possible. - */ - if (set) - *reg |= __feature_bit(x86_feature); - else - *reg &= ~__feature_bit(x86_feature); -} - static __always_inline void cpuid_entry_override(struct kvm_cpuid_entry2 *entry, unsigned int leaf) { diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h new file mode 100644 index 000000000000..8e0756ddab1a --- /dev/null +++ b/arch/x86/kvm/reverse_cpuid.h @@ -0,0 +1,185 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef ARCH_X86_KVM_REVERSE_CPUID_H +#define ARCH_X86_KVM_REVERSE_CPUID_H + +#include <uapi/asm/kvm.h> +#include <asm/cpufeature.h> +#include <asm/cpufeatures.h> + +/* + * Hardware-defined CPUID leafs that are scattered in the kernel, but need to + * be directly used by KVM. Note, these word values conflict with the kernel's + * "bug" caps, but KVM doesn't use those. + */ +enum kvm_only_cpuid_leafs { + CPUID_12_EAX = NCAPINTS, + NR_KVM_CPU_CAPS, + + NKVMCAPINTS = NR_KVM_CPU_CAPS - NCAPINTS, +}; + +#define KVM_X86_FEATURE(w, f) ((w)*32 + (f)) + +/* Intel-defined SGX sub-features, CPUID level 0x12 (EAX). */ +#define KVM_X86_FEATURE_SGX1 KVM_X86_FEATURE(CPUID_12_EAX, 0) +#define KVM_X86_FEATURE_SGX2 KVM_X86_FEATURE(CPUID_12_EAX, 1) + +struct cpuid_reg { + u32 function; + u32 index; + int reg; +}; + +static const struct cpuid_reg reverse_cpuid[] = { + [CPUID_1_EDX] = { 1, 0, CPUID_EDX}, + [CPUID_8000_0001_EDX] = {0x80000001, 0, CPUID_EDX}, + [CPUID_8086_0001_EDX] = {0x80860001, 0, CPUID_EDX}, + [CPUID_1_ECX] = { 1, 0, CPUID_ECX}, + [CPUID_C000_0001_EDX] = {0xc0000001, 0, CPUID_EDX}, + [CPUID_8000_0001_ECX] = {0x80000001, 0, CPUID_ECX}, + [CPUID_7_0_EBX] = { 7, 0, CPUID_EBX}, + [CPUID_D_1_EAX] = { 0xd, 1, CPUID_EAX}, + [CPUID_8000_0008_EBX] = {0x80000008, 0, CPUID_EBX}, + [CPUID_6_EAX] = { 6, 0, CPUID_EAX}, + [CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX}, + [CPUID_7_ECX] = { 7, 0, CPUID_ECX}, + [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX}, + [CPUID_7_EDX] = { 7, 0, CPUID_EDX}, + [CPUID_7_1_EAX] = { 7, 1, CPUID_EAX}, + [CPUID_12_EAX] = {0x00000012, 0, CPUID_EAX}, +}; + +/* + * Reverse CPUID and its derivatives can only be used for hardware-defined + * feature words, i.e. words whose bits directly correspond to a CPUID leaf. + * Retrieving a feature bit or masking guest CPUID from a Linux-defined word + * is nonsensical as the bit number/mask is an arbitrary software-defined value + * and can't be used by KVM to query/control guest capabilities. And obviously + * the leaf being queried must have an entry in the lookup table. + */ +static __always_inline void reverse_cpuid_check(unsigned int x86_leaf) +{ + BUILD_BUG_ON(x86_leaf == CPUID_LNX_1); + BUILD_BUG_ON(x86_leaf == CPUID_LNX_2); + BUILD_BUG_ON(x86_leaf == CPUID_LNX_3); + BUILD_BUG_ON(x86_leaf == CPUID_LNX_4); + BUILD_BUG_ON(x86_leaf >= ARRAY_SIZE(reverse_cpuid)); + BUILD_BUG_ON(reverse_cpuid[x86_leaf].function == 0); +} + +/* + * Translate feature bits that are scattered in the kernel's cpufeatures word + * into KVM feature words that align with hardware's definitions. + */ +static __always_inline u32 __feature_translate(int x86_feature) +{ + if (x86_feature == X86_FEATURE_SGX1) + return KVM_X86_FEATURE_SGX1; + else if (x86_feature == X86_FEATURE_SGX2) + return KVM_X86_FEATURE_SGX2; + + return x86_feature; +} + +static __always_inline u32 __feature_leaf(int x86_feature) +{ + return __feature_translate(x86_feature) / 32; +} + +/* + * Retrieve the bit mask from an X86_FEATURE_* definition. Features contain + * the hardware defined bit number (stored in bits 4:0) and a software defined + * "word" (stored in bits 31:5). The word is used to index into arrays of + * bit masks that hold the per-cpu feature capabilities, e.g. this_cpu_has(). + */ +static __always_inline u32 __feature_bit(int x86_feature) +{ + x86_feature = __feature_translate(x86_feature); + + reverse_cpuid_check(x86_feature / 32); + return 1 << (x86_feature & 31); +} + +#define feature_bit(name) __feature_bit(X86_FEATURE_##name) + +static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned int x86_feature) +{ + unsigned int x86_leaf = __feature_leaf(x86_feature); + + reverse_cpuid_check(x86_leaf); + return reverse_cpuid[x86_leaf]; +} + +static __always_inline u32 *__cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry, + u32 reg) +{ + switch (reg) { + case CPUID_EAX: + return &entry->eax; + case CPUID_EBX: + return &entry->ebx; + case CPUID_ECX: + return &entry->ecx; + case CPUID_EDX: + return &entry->edx; + default: + BUILD_BUG(); + return NULL; + } +} + +static __always_inline u32 *cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry, + unsigned int x86_feature) +{ + const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature); + + return __cpuid_entry_get_reg(entry, cpuid.reg); +} + +static __always_inline u32 cpuid_entry_get(struct kvm_cpuid_entry2 *entry, + unsigned int x86_feature) +{ + u32 *reg = cpuid_entry_get_reg(entry, x86_feature); + + return *reg & __feature_bit(x86_feature); +} + +static __always_inline bool cpuid_entry_has(struct kvm_cpuid_entry2 *entry, + unsigned int x86_feature) +{ + return cpuid_entry_get(entry, x86_feature); +} + +static __always_inline void cpuid_entry_clear(struct kvm_cpuid_entry2 *entry, + unsigned int x86_feature) +{ + u32 *reg = cpuid_entry_get_reg(entry, x86_feature); + + *reg &= ~__feature_bit(x86_feature); +} + +static __always_inline void cpuid_entry_set(struct kvm_cpuid_entry2 *entry, + unsigned int x86_feature) +{ + u32 *reg = cpuid_entry_get_reg(entry, x86_feature); + + *reg |= __feature_bit(x86_feature); +} + +static __always_inline void cpuid_entry_change(struct kvm_cpuid_entry2 *entry, + unsigned int x86_feature, + bool set) +{ + u32 *reg = cpuid_entry_get_reg(entry, x86_feature); + + /* + * Open coded instead of using cpuid_entry_{clear,set}() to coerce the + * compiler into using CMOV instead of Jcc when possible. + */ + if (set) + *reg |= __feature_bit(x86_feature); + else + *reg &= ~__feature_bit(x86_feature); +} + +#endif /* ARCH_X86_KVM_REVERSE_CPUID_H */ |