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/powerpc.c b/arch/powerpc/kvm/powerpc.c
index bad40bd..777e0f3 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -36,13 +36,12 @@
int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
{
- /* XXX implement me */
- return 0;
+ return !!(v->arch.pending_exceptions);
}
int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
{
- return 1;
+ return !(v->arch.msr & MSR_WE);
}
@@ -214,6 +213,11 @@
struct kvm_vcpu *vcpu = (struct kvm_vcpu *)data;
kvmppc_queue_exception(vcpu, BOOKE_INTERRUPT_DECREMENTER);
+
+ if (waitqueue_active(&vcpu->wq)) {
+ wake_up_interruptible(&vcpu->wq);
+ vcpu->stat.halt_wakeup++;
+ }
}
int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
@@ -339,6 +343,8 @@
int r;
sigset_t sigsaved;
+ vcpu_load(vcpu);
+
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
@@ -363,12 +369,20 @@
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &sigsaved, NULL);
+ vcpu_put(vcpu);
+
return r;
}
int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
{
kvmppc_queue_exception(vcpu, BOOKE_INTERRUPT_EXTERNAL);
+
+ if (waitqueue_active(&vcpu->wq)) {
+ wake_up_interruptible(&vcpu->wq);
+ vcpu->stat.halt_wakeup++;
+ }
+
return 0;
}