KVM: in-kernel IOAPIC save and restore support

This patch adds support for in-kernel ioapic save and restore (to
and from userspace). It uses the same get/set_irqchip ioctl as
in-kernel PIC.

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

drivers/kvm/irq.h

@@ -61,7 +61,7 @@ int kvm_cpu_get_interrupt(struct kvm_vcpu *v);
 int kvm_cpu_has_interrupt(struct kvm_vcpu *v);
 void kvm_pic_update_irq(struct kvm_pic *s);
 
-#define IOAPIC_NUM_PINS  24
+#define IOAPIC_NUM_PINS  KVM_IOAPIC_NUM_PINS
 #define IOAPIC_VERSION_ID 0x11	/* IOAPIC version */
 #define IOAPIC_EDGE_TRIG  0
 #define IOAPIC_LEVEL_TRIG 1

drivers/kvm/kvm_main.c

@@ -913,6 +913,11 @@ static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
 			&pic_irqchip(kvm)->pics[1],
 			sizeof(struct kvm_pic_state));
 		break;
+	case KVM_IRQCHIP_IOAPIC:
+		memcpy (&chip->chip.ioapic,
+			ioapic_irqchip(kvm),
+			sizeof(struct kvm_ioapic_state));
+		break;
 	default:
 		r = -EINVAL;
 		break;
@@ -936,6 +941,11 @@ static int kvm_vm_ioctl_set_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
 			&chip->chip.pic,
 			sizeof(struct kvm_pic_state));
 		break;
+	case KVM_IRQCHIP_IOAPIC:
+		memcpy (ioapic_irqchip(kvm),
+			&chip->chip.ioapic,
+			sizeof(struct kvm_ioapic_state));
+		break;
 	default:
 		r = -EINVAL;
 		break;

include/linux/kvm.h

@@ -45,7 +45,7 @@ struct kvm_irq_level {
 	__u32 level;
 };
 
-/* for KVM_GET_IRQCHIP / KVM_SET_IRQCHIP */
+/* for KVM_GET_IRQCHIP and KVM_SET_IRQCHIP */
 struct kvm_pic_state {
 	__u8 last_irr;	/* edge detection */
 	__u8 irr;		/* interrupt request register */
@@ -65,9 +65,35 @@ struct kvm_pic_state {
 	__u8 elcr_mask;
 };
 
+#define KVM_IOAPIC_NUM_PINS  24
+struct kvm_ioapic_state {
+	__u64 base_address;
+	__u32 ioregsel;
+	__u32 id;
+	__u32 irr;
+	__u32 pad;
+	union {
+		__u64 bits;
+		struct {
+			__u8 vector;
+			__u8 delivery_mode:3;
+			__u8 dest_mode:1;
+			__u8 delivery_status:1;
+			__u8 polarity:1;
+			__u8 remote_irr:1;
+			__u8 trig_mode:1;
+			__u8 mask:1;
+			__u8 reserve:7;
+			__u8 reserved[4];
+			__u8 dest_id;
+		} fields;
+	} redirtbl[KVM_IOAPIC_NUM_PINS];
+};
+
 enum kvm_irqchip_id {
 	KVM_IRQCHIP_PIC_MASTER	 = 0,
 	KVM_IRQCHIP_PIC_SLAVE	 = 1,
+	KVM_IRQCHIP_IOAPIC       = 2,
 };
 
 struct kvm_irqchip {
@@ -76,6 +102,7 @@ struct kvm_irqchip {
         union {
 		char dummy[512];  /* reserving space */
 		struct kvm_pic_state pic;
+		struct kvm_ioapic_state ioapic;
 	} chip;
 };