From 3e7c61822a75537932cb467f0e8adb05ec8c95a5 Mon Sep 17 00:00:00 2001
From: Alexander Graf <agraf@suse.de>
Date: Tue, 24 Aug 2010 15:48:51 +0200
Subject: [PATCH] --- yaml --- r: 215780 b: refs/heads/master c:
 cefa33e2f8f7852abb42f22ec25a6084a931c5ac h: refs/heads/master v: v3

---
 [refs]                                   |  2 +-
 trunk/arch/s390/include/asm/kvm_virtio.h |  1 +
 trunk/drivers/s390/kvm/kvm_virtio.c      | 47 ++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index c24f1250dfa3..3e79c3bb644e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: fc678d67fee1acccf21322318dd833b892a572e4
+refs/heads/master: cefa33e2f8f7852abb42f22ec25a6084a931c5ac
diff --git a/trunk/arch/s390/include/asm/kvm_virtio.h b/trunk/arch/s390/include/asm/kvm_virtio.h
index 3f5d100a42a2..72f614181eff 100644
--- a/trunk/arch/s390/include/asm/kvm_virtio.h
+++ b/trunk/arch/s390/include/asm/kvm_virtio.h
@@ -59,5 +59,6 @@ struct kvm_vqconfig {
 #define VIRTIO_PARAM_MASK		0xff
 #define VIRTIO_PARAM_VRING_INTERRUPT	0x0
 #define VIRTIO_PARAM_CONFIG_CHANGED	0x1
+#define VIRTIO_PARAM_DEV_ADD		0x2
 
 #endif
diff --git a/trunk/drivers/s390/kvm/kvm_virtio.c b/trunk/drivers/s390/kvm/kvm_virtio.c
index 68cef4da15e8..5a46b8c5d68a 100644
--- a/trunk/drivers/s390/kvm/kvm_virtio.c
+++ b/trunk/drivers/s390/kvm/kvm_virtio.c
@@ -32,6 +32,7 @@
  * The pointer to our (page) of device descriptions.
  */
 static void *kvm_devices;
+struct work_struct hotplug_work;
 
 struct kvm_device {
 	struct virtio_device vdev;
@@ -327,6 +328,47 @@ static void scan_devices(void)
 	}
 }
 
+/*
+ * match for a kvm device with a specific desc pointer
+ */
+static int match_desc(struct device *dev, void *data)
+{
+	if ((ulong)to_kvmdev(dev_to_virtio(dev))->desc == (ulong)data)
+		return 1;
+
+	return 0;
+}
+
+/*
+ * hotplug_device tries to find changes in the device page.
+ */
+static void hotplug_devices(struct work_struct *dummy)
+{
+	unsigned int i;
+	struct kvm_device_desc *d;
+	struct device *dev;
+
+	for (i = 0; i < PAGE_SIZE; i += desc_size(d)) {
+		d = kvm_devices + i;
+
+		/* end of list */
+		if (d->type == 0)
+			break;
+
+		/* device already exists */
+		dev = device_find_child(kvm_root, d, match_desc);
+		if (dev) {
+			/* XXX check for hotplug remove */
+			put_device(dev);
+			continue;
+		}
+
+		/* new device */
+		printk(KERN_INFO "Adding new virtio device %p\n", d);
+		add_kvm_device(d, i);
+	}
+}
+
 /*
  * we emulate the request_irq behaviour on top of s390 extints
  */
@@ -357,6 +399,9 @@ static void kvm_extint_handler(u16 code)
 
 		break;
 	}
+	case VIRTIO_PARAM_DEV_ADD:
+		schedule_work(&hotplug_work);
+		break;
 	case VIRTIO_PARAM_VRING_INTERRUPT:
 	default:
 		vring_interrupt(0, vq);
@@ -390,6 +435,8 @@ static int __init kvm_devices_init(void)
 
 	kvm_devices = (void *) real_memory_size;
 
+	INIT_WORK(&hotplug_work, hotplug_devices);
+
 	ctl_set_bit(0, 9);
 	register_external_interrupt(0x2603, kvm_extint_handler);