KVM: ppc: improve trap emulation

set ESR[PTR] when emulating a guest trap. This allows Linux guests to
properly handle WARN_ON() (i.e. detect that it's a non-fatal trap).

Also remove debugging printk in trap emulation.
Signed-off-by: NHollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

arch/powerpc/kvm/emulate.c

@@ -75,7 +75,7 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 
 	switch (get_op(inst)) {
 	case 3:                                             /* trap */
-		printk("trap!\n");
+		vcpu->arch.esr |= ESR_PTR;
 		kvmppc_core_queue_program(vcpu);
 		advance = 0;
 		break;