KVM/VMX: Use TEST %REG,%REG instead of CMP $0,%REG in vmenter.S

commit 2eff89ce4bfd405227462646adfa9407c50627f7 upstream.

Saves one byte in __vmx_vcpu_run for the same functionality.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Message-Id: <20201029140457.126965-1-ubizjak@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S
index ca4252f81bf81edf8c921cc5784f8030210ff7b3..63cd7fbab0ac15d18100e04bc3dce5e8eac950a1 100644 (file)
--- a/arch/x86/kvm/vmx/vmenter.S
+++ b/arch/x86/kvm/vmx/vmenter.S
@@ -135,7 +135,7 @@ ENTRY(__vmx_vcpu_run)
        mov (%_ASM_SP), %_ASM_AX
 
        /* Check if vmlaunch or vmresume is needed */
-       cmpb $0, %bl
+       testb %bl, %bl
 
        /* Load guest registers.  Don't clobber flags. */
        mov VCPU_RBX(%_ASM_AX), %_ASM_BX