KVM: ppc: Handle guest idle by emulating MSR[WE] writes

This reduces host CPU usage when the guest is idle. However, the guest must
set MSR[WE] in its idle loop, which Linux did not do until 2.6.26.

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Signed-off-by: Jerone Young <jyoung5@us.ibm.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/powerpc/kvm/booke_guest.c b/arch/powerpc/kvm/booke_guest.c
index 6d9884a..b3db6f4 100644
--- a/arch/powerpc/kvm/booke_guest.c
+++ b/arch/powerpc/kvm/booke_guest.c
@@ -49,6 +49,7 @@
 	{ "inst_emu",   VCPU_STAT(emulated_inst_exits) },
 	{ "dec",        VCPU_STAT(dec_exits) },
 	{ "ext_intr",   VCPU_STAT(ext_intr_exits) },
+	{ "halt_wakeup", VCPU_STAT(halt_wakeup) },
 	{ NULL }
 };