KVM: Add get/set irqchip ioctls for in-kernel PIC live migration support

This patch adds two new ioctls to dump and write kernel irqchips for
save/restore and live migration. PIC s/r and l/m is implemented in this
patch.

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

3 files changed, 88 insertions, 0 deletions

diff --git a/drivers/kvm/i8259.c b/drivers/kvm/i8259.c
index ee6030dc5c0..a679157bc59 100644
--- a/drivers/kvm/i8259.c
+++ b/drivers/kvm/i8259.c
@@ -119,6 +119,11 @@ static void pic_update_irq(struct kvm_pic *s)
 		s->irq_request(s->irq_request_opaque, 0);
 }
 
+void kvm_pic_update_irq(struct kvm_pic *s)
+{
+	pic_update_irq(s);
+}
+
 void kvm_pic_set_irq(void *opaque, int irq, int level)
 {
 	struct kvm_pic *s = opaque;
diff --git a/drivers/kvm/irq.h b/drivers/kvm/irq.h
index 6ed856a41e2..4034f6576cd 100644
--- a/drivers/kvm/irq.h
+++ b/drivers/kvm/irq.h
@@ -59,6 +59,7 @@ void kvm_pic_set_irq(void *opaque, int irq, int level);
 int kvm_pic_read_irq(struct kvm_pic *s);
 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_VERSION_ID 0x11	/* IOAPIC version */
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 5063b3addbb..6e2c5f3f33f 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -897,6 +897,53 @@ out:
 	return r;
 }
 
+static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
+{
+	int r;
+
+	r = 0;
+	switch (chip->chip_id) {
+	case KVM_IRQCHIP_PIC_MASTER:
+		memcpy (&chip->chip.pic,
+			&pic_irqchip(kvm)->pics[0],
+			sizeof(struct kvm_pic_state));
+		break;
+	case KVM_IRQCHIP_PIC_SLAVE:
+		memcpy (&chip->chip.pic,
+			&pic_irqchip(kvm)->pics[1],
+			sizeof(struct kvm_pic_state));
+		break;
+	default:
+		r = -EINVAL;
+		break;
+	}
+	return r;
+}
+
+static int kvm_vm_ioctl_set_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
+{
+	int r;
+
+	r = 0;
+	switch (chip->chip_id) {
+	case KVM_IRQCHIP_PIC_MASTER:
+		memcpy (&pic_irqchip(kvm)->pics[0],
+			&chip->chip.pic,
+			sizeof(struct kvm_pic_state));
+		break;
+	case KVM_IRQCHIP_PIC_SLAVE:
+		memcpy (&pic_irqchip(kvm)->pics[1],
+			&chip->chip.pic,
+			sizeof(struct kvm_pic_state));
+		break;
+	default:
+		r = -EINVAL;
+		break;
+	}
+	kvm_pic_update_irq(pic_irqchip(kvm));
+	return r;
+}
+
 static gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn)
 {
 	int i;
@@ -2835,6 +2882,41 @@ static long kvm_vm_ioctl(struct file *filp,
 		}
 		break;
 	}
+	case KVM_GET_IRQCHIP: {
+		/* 0: PIC master, 1: PIC slave, 2: IOAPIC */
+		struct kvm_irqchip chip;
+
+		r = -EFAULT;
+		if (copy_from_user(&chip, argp, sizeof chip))
+			goto out;
+		r = -ENXIO;
+		if (!irqchip_in_kernel(kvm))
+			goto out;
+		r = kvm_vm_ioctl_get_irqchip(kvm, &chip);
+		if (r)
+			goto out;
+		r = -EFAULT;
+		if (copy_to_user(argp, &chip, sizeof chip))
+			goto out;
+		r = 0;
+		break;
+	}
+	case KVM_SET_IRQCHIP: {
+		/* 0: PIC master, 1: PIC slave, 2: IOAPIC */
+		struct kvm_irqchip chip;
+
+		r = -EFAULT;
+		if (copy_from_user(&chip, argp, sizeof chip))
+			goto out;
+		r = -ENXIO;
+		if (!irqchip_in_kernel(kvm))
+			goto out;
+		r = kvm_vm_ioctl_set_irqchip(kvm, &chip);
+		if (r)
+			goto out;
+		r = 0;
+		break;
+	}
 	default:
 		;
 	}