diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2019-04-10 11:41:40 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-04-16 15:39:02 +0200 |
| commit | 674ea351cdeb01d2740edce31db7f2d79ce6095d (patch) | |
| tree | aaabcbffb1ebd5543da17d648b3818e5014b01f9 /arch | |
| parent | f16cb57be82b20c6a00a6bb1750cb77c08e56c1a (diff) | |
| download | linux-674ea351cdeb01d2740edce31db7f2d79ce6095d.tar.bz2 | |
KVM: x86: optimize check for valid PAT value
This check will soon be done on every nested vmentry and vmexit,
"parallelize" it using bitwise operations.
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/mtrr.c | 10 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.h | 10 |
3 files changed, 12 insertions, 10 deletions
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c index e9ea2d45ae66..9f72cc427158 100644 --- a/arch/x86/kvm/mtrr.c +++ b/arch/x86/kvm/mtrr.c @@ -48,11 +48,6 @@ static bool msr_mtrr_valid(unsigned msr) return false; } -static bool valid_pat_type(unsigned t) -{ - return t < 8 && (1 << t) & 0xf3; /* 0, 1, 4, 5, 6, 7 */ -} - static bool valid_mtrr_type(unsigned t) { return t < 8 && (1 << t) & 0x73; /* 0, 1, 4, 5, 6 */ @@ -67,10 +62,7 @@ bool kvm_mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data) return false; if (msr == MSR_IA32_CR_PAT) { - for (i = 0; i < 8; i++) - if (!valid_pat_type((data >> (i * 8)) & 0xff)) - return false; - return true; + return kvm_pat_valid(data); } else if (msr == MSR_MTRRdefType) { if (data & ~0xcff) return false; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index a8a1e533d7fb..c40fb667002c 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1891,7 +1891,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) break; case MSR_IA32_CR_PAT: if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) { - if (!kvm_mtrr_valid(vcpu, MSR_IA32_CR_PAT, data)) + if (!kvm_pat_valid(data)) return 1; vmcs_write64(GUEST_IA32_PAT, data); vcpu->arch.pat = data; diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index aedc5d0d4989..eda954441213 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -347,6 +347,16 @@ static inline void kvm_after_interrupt(struct kvm_vcpu *vcpu) __this_cpu_write(current_vcpu, NULL); } + +static inline bool kvm_pat_valid(u64 data) +{ + if (data & 0xF8F8F8F8F8F8F8F8ull) + return false; + /* 0, 1, 4, 5, 6, 7 are valid values. */ + return (data | ((data & 0x0202020202020202ull) << 1)) == data; +} + void kvm_load_guest_xcr0(struct kvm_vcpu *vcpu); void kvm_put_guest_xcr0(struct kvm_vcpu *vcpu); + #endif |