KVM: Emulate hlt in the kernel

By sleeping in the kernel when hlt is executed, we simplify the in-kernel
guest interrupt path considerably.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index d576451..a347b61 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -1398,9 +1398,12 @@
 static void post_kvm_run_save(struct vcpu_svm *svm,
 			      struct kvm_run *kvm_run)
 {
-	kvm_run->ready_for_interrupt_injection
-		= (svm->vcpu.interrupt_window_open &&
-		   svm->vcpu.irq_summary == 0);
+	if (irqchip_in_kernel(svm->vcpu.kvm))
+		kvm_run->ready_for_interrupt_injection = 1;
+	else
+		kvm_run->ready_for_interrupt_injection =
+					 (svm->vcpu.interrupt_window_open &&
+					  svm->vcpu.irq_summary == 0);
 	kvm_run->if_flag = (svm->vmcb->save.rflags & X86_EFLAGS_IF) != 0;
 	kvm_run->cr8 = get_cr8(&svm->vcpu);
 	kvm_run->apic_base = kvm_get_apic_base(&svm->vcpu);