KVM: PPC: Add AGAIN type for emulation return

Emulation of an instruction can have different outcomes. It can succeed,
fail, require MMIO, do funky BookE stuff - or it can just realize something's
odd and will be fixed the next time around.

Exactly that is what EMULATE_AGAIN means. Using that flag we can now tell
the caller that nothing happened, but we still want to go back to the
guest and see what happens next time we come around.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/powerpc/kvm/book3s.c

@@ -789,6 +789,9 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
 		case EMULATE_DONE:
 			r = RESUME_GUEST_NV;
 			break;
+		case EMULATE_AGAIN:
+			r = RESUME_GUEST;
+			break;
 		case EMULATE_FAIL:
 			printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n",
 			       __func__, vcpu->arch.pc, vcpu->arch.last_inst);