1 files changed, 68 insertions, 11 deletions

diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c
index 4e298bc8949d..aec60d55b10d 100644
--- a/drivers/s390/kvm/kvm_virtio.c
+++ b/drivers/s390/kvm/kvm_virtio.c
@@ -10,6 +10,7 @@
  *    Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
  */
 
+#include <linux/kernel_stat.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
 #include <linux/err.h>
@@ -24,7 +25,7 @@
 #include <asm/kvm_para.h>
 #include <asm/kvm_virtio.h>
 #include <asm/setup.h>
-#include <asm/s390_ext.h>
+#include <asm/irq.h>
 
 #define VIRTIO_SUBCODE_64 0x0D00
 
@@ -32,6 +33,7 @@
  * The pointer to our (page) of device descriptions.
  */
 static void *kvm_devices;
+struct work_struct hotplug_work;
 
 struct kvm_device {
         struct virtio_device vdev;
@@ -328,33 +330,86 @@ 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
  */
-static void kvm_extint_handler(u16 code)
+static void kvm_extint_handler(unsigned int ext_int_code,
+                               unsigned int param32, unsigned long param64)
 {
         struct virtqueue *vq;
         u16 subcode;
-        int config_changed;
+        u32 param;
 
-        subcode = S390_lowcore.cpu_addr;
+        subcode = ext_int_code >> 16;
         if ((subcode & 0xff00) != VIRTIO_SUBCODE_64)
                 return;
+        kstat_cpu(smp_processor_id()).irqs[EXTINT_VRT]++;
 
         /* The LSB might be overloaded, we have to mask it */
-        vq = (struct virtqueue *)(S390_lowcore.ext_params2 & ~1UL);
+        vq = (struct virtqueue *)(param64 & ~1UL);
 
-        /* We use the LSB of extparam, to decide, if this interrupt is a config
-         * change or a "standard" interrupt */
-        config_changed = S390_lowcore.ext_params & 1;
+        /* We use ext_params to decide what this interrupt means */
+        param = param32 & VIRTIO_PARAM_MASK;
 
-        if (config_changed) {
+        switch (param) {
+        case VIRTIO_PARAM_CONFIG_CHANGED:
+        {
                 struct virtio_driver *drv;
                 drv = container_of(vq->vdev->dev.driver,
                                    struct virtio_driver, driver);
                 if (drv->config_changed)
                         drv->config_changed(vq->vdev);
-        } else
+
+                break;
+        }
+        case VIRTIO_PARAM_DEV_ADD:
+                schedule_work(&hotplug_work);
+                break;
+        case VIRTIO_PARAM_VRING_INTERRUPT:
+        default:
                 vring_interrupt(0, vq);
+                break;
+        }
 }
 
 /*
@@ -383,7 +438,9 @@ static int __init kvm_devices_init(void)
 
         kvm_devices = (void *) real_memory_size;
 
-        ctl_set_bit(0, 9);
+        INIT_WORK(&hotplug_work, hotplug_devices);
+
+        service_subclass_irq_register();
         register_external_interrupt(0x2603, kvm_extint_handler);
 
         scan_devices();