[PATCH 5.4 24/51] KVM/VMX: Use TEST %REG,%REG instead of CMP $0,%REG in vmenter.S

[Greg Kroah-Hartman]

From: Uros Bizjak <ubizjak@xxxxxxxxx>

commit 6c44221b05236cc65d76cb5dc2463f738edff39d upstream.

Saves one byte in __vmx_vcpu_run for the same functionality.

Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Message-Id: <20201029140457.126965-1-ubizjak@xxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/x86/kvm/vmx/vmenter.S |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 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