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authorPaolo Bonzini <pbonzini@redhat.com>2019-04-10 11:41:40 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2019-04-16 15:39:02 +0200
commit674ea351cdeb01d2740edce31db7f2d79ce6095d (patch)
treeaaabcbffb1ebd5543da17d648b3818e5014b01f9 /arch/x86/kvm
parentKVM: x86: clear VM_EXIT_SAVE_IA32_PAT (diff)
downloadlinux-674ea351cdeb01d2740edce31db7f2d79ce6095d.tar.xz
linux-674ea351cdeb01d2740edce31db7f2d79ce6095d.zip
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/x86/kvm')
-rw-r--r--arch/x86/kvm/mtrr.c10
-rw-r--r--arch/x86/kvm/vmx/vmx.c2
-rw-r--r--arch/x86/kvm/x86.h10
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