KVM: Add support for in-kernel PIC emulation

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

drivers/kvm/irq.c

@@ -0,0 +1,61 @@
+/*
+ * irq.c: API for in kernel interrupt controller
+ * Copyright (c) 2007, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ * Authors:
+ *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
+ *
+ */
+
+#include <linux/module.h>
+
+#include "kvm.h"
+#include "irq.h"
+
+/*
+ * check if there is pending interrupt without
+ * intack.
+ */
+int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
+{
+	struct kvm_pic *s = pic_irqchip(v->kvm);
+
+	if (s->output)	/* PIC */
+		return 1;
+	/*
+	 * TODO: APIC
+	 */
+	return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
+
+/*
+ * Read pending interrupt vector and intack.
+ */
+int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
+{
+	struct kvm_pic *s = pic_irqchip(v->kvm);
+	int vector;
+
+	s->output = 0;
+	vector = kvm_pic_read_irq(s);
+	if (vector != -1)
+		return vector;
+	/*
+	 * TODO: APIC
+	 */
+	return -1;
+}
+EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);