KVM: VMX: Optimize vmx_get_cpl()

Instead of calling vmx_get_segment() (which reads a whole bunch of
vmcs fields), read only the cs selector which contains the cpl.

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 1 insertions, 4 deletions

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 32e6d2031ba2..0ba706e87c50 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1773,16 +1773,13 @@ static void vmx_get_segment(struct kvm_vcpu *vcpu,
 
 static int vmx_get_cpl(struct kvm_vcpu *vcpu)
 {
-        struct kvm_segment kvm_seg;
-
         if (!(vcpu->arch.cr0 & X86_CR0_PE)) /* if real mode */
                 return 0;
 
         if (vmx_get_rflags(vcpu) & X86_EFLAGS_VM) /* if virtual 8086 */
                 return 3;
 
-        vmx_get_segment(vcpu, &kvm_seg, VCPU_SREG_CS);
-        return kvm_seg.selector & 3;
+        return vmcs_read16(GUEST_CS_SELECTOR) & 3;
 }
 
 static u32 vmx_segment_access_rights(struct kvm_segment *var)