diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-03-02 15:56:31 -0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-03-16 17:58:15 +0100 |
| commit | b32666b13a72a1fd9f5078d8142bd7325022520f (patch) | |
| tree | 3526e5cf01b80759209e9a7659fd3662701ead99 /arch/x86/kvm/cpuid.h | |
| parent | 4c61534aaae2a170bf0abd72676624fd3fabc655 (diff) | |
KVM: x86: Introduce cpuid_entry_{change,set,clear}() mutators
Introduce mutators to modify feature bits in CPUID entries and use the
new mutators where applicable. Using the mutators eliminates the need
to manually specify the register to modify query at no extra cost and
will allow adding runtime consistency checks on the function/index in a
future patch.
No functional change intended.
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/cpuid.h')
| -rw-r--r-- | arch/x86/kvm/cpuid.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h index bf95428ddf4e..de3c6c365a5a 100644 --- a/arch/x86/kvm/cpuid.h +++ b/arch/x86/kvm/cpuid.h @@ -135,6 +135,38 @@ static __always_inline bool cpuid_entry_has(struct kvm_cpuid_entry2 *entry, 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 u32 *guest_cpuid_get_register(struct kvm_vcpu *vcpu, unsigned int x86_feature) { |