/* SPDX-License-Identifier: GPL-2.0 */
#ifndef ARCH_X86_KVM_CPUID_H
#define ARCH_X86_KVM_CPUID_H

#include "x86.h"
#include <asm/cpu.h>
#include <asm/processor.h>

extern u32 kvm_cpu_caps[NCAPINTS] __read_mostly;
void kvm_set_cpu_caps(void);

void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu);
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);
int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
                             struct kvm_cpuid *cpuid,
                             struct kvm_cpuid_entry __user *entries);
int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
                              struct kvm_cpuid2 *cpuid,
                              struct kvm_cpuid_entry2 __user *entries);
int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
                              struct kvm_cpuid2 *cpuid,
                              struct kvm_cpuid_entry2 __user *entries);
bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
               u32 *ecx, u32 *edx, bool exact_only);

int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu);

static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
{
        return vcpu->arch.maxphyaddr;
}

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},
};

/*
 * 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);
}

/*
 * 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)
{
        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 = x86_feature / 32;

        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,
                                                 enum cpuid_leafs leaf)
{
        u32 *reg = cpuid_entry_get_reg(entry, leaf * 32);

        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,
                                                     unsigned int x86_feature)
{
        const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
        struct kvm_cpuid_entry2 *entry;

        entry = kvm_find_cpuid_entry(vcpu, cpuid.function, cpuid.index);
        if (!entry)
                return NULL;

        return __cpuid_entry_get_reg(entry, cpuid.reg);
}

static __always_inline bool guest_cpuid_has(struct kvm_vcpu *vcpu,
                                            unsigned int x86_feature)
{
        u32 *reg;

        reg = guest_cpuid_get_register(vcpu, x86_feature);
        if (!reg)
                return false;

        return *reg & __feature_bit(x86_feature);
}

static __always_inline void guest_cpuid_clear(struct kvm_vcpu *vcpu,
                                              unsigned int x86_feature)
{
        u32 *reg;

        reg = guest_cpuid_get_register(vcpu, x86_feature);
        if (reg)
                *reg &= ~__feature_bit(x86_feature);
}

static inline bool guest_cpuid_is_amd_or_hygon(struct kvm_vcpu *vcpu)
{
        struct kvm_cpuid_entry2 *best;

        best = kvm_find_cpuid_entry(vcpu, 0, 0);
        return best &&
               (is_guest_vendor_amd(best->ebx, best->ecx, best->edx) ||
                is_guest_vendor_hygon(best->ebx, best->ecx, best->edx));
}

static inline int guest_cpuid_family(struct kvm_vcpu *vcpu)
{
        struct kvm_cpuid_entry2 *best;

        best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
        if (!best)
                return -1;

        return x86_family(best->eax);
}

static inline int guest_cpuid_model(struct kvm_vcpu *vcpu)
{
        struct kvm_cpuid_entry2 *best;

        best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
        if (!best)
                return -1;

        return x86_model(best->eax);
}

static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu)
{
        struct kvm_cpuid_entry2 *best;

        best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
        if (!best)
                return -1;

        return x86_stepping(best->eax);
}

static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu)
{
        return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT;
}

static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu)
{
        return vcpu->arch.msr_misc_features_enables &
                  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);
}

static __always_inline u32 kvm_cpu_cap_get(unsigned int x86_feature)
{
        unsigned int x86_leaf = x86_feature / 32;

        reverse_cpuid_check(x86_leaf);
        return kvm_cpu_caps[x86_leaf] & __feature_bit(x86_feature);
}

static __always_inline bool kvm_cpu_cap_has(unsigned int x86_feature)
{
        return !!kvm_cpu_cap_get(x86_feature);
}

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 page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa)
{
        return PAGE_ALIGNED(gpa) && !(gpa >> cpuid_maxphyaddr(vcpu));
}

#endif