Added ONE_REG interface for debug instruction

This patch adds the one_reg interface to get the special instruction
to be used for setting software breakpoint from userspace.

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 6548445..2d32ae4 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -529,6 +529,12 @@
 			val = get_reg_val(reg->id, vcpu->arch.vscr.u[3]);
 			break;
 #endif /* CONFIG_ALTIVEC */
+		case KVM_REG_PPC_DEBUG_INST: {
+			u32 opcode = INS_TW;
+			r = copy_to_user((u32 __user *)(long)reg->addr,
+					 &opcode, sizeof(u32));
+			break;
+		}
 		default:
 			r = -EINVAL;
 			break;