KVM: x86: Processor mode may be determined incorrectly

If EFER.LMA is off, cs.l does not determine execution mode.
Currently, the emulation engine assumes differently.
Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/x86.c

@@ -4888,7 +4888,7 @@ static void init_emulate_ctxt(struct kvm_vcpu *vcpu)
 	ctxt->eip = kvm_rip_read(vcpu);
 	ctxt->mode = (!is_protmode(vcpu))		? X86EMUL_MODE_REAL :
 		     (ctxt->eflags & X86_EFLAGS_VM)	? X86EMUL_MODE_VM86 :
-		     cs_l				? X86EMUL_MODE_PROT64 :
+		     (cs_l && is_long_mode(vcpu))	? X86EMUL_MODE_PROT64 :
 		     cs_db				? X86EMUL_MODE_PROT32 :
 							  X86EMUL_MODE_PROT16;
 	ctxt->guest_mode = is_guest_mode(vcpu);