[Qemu-devel] [PATCH 1/5] [S390] Add hotplug support

[Alexander Graf <agraf@suse.de>]

I just submitted a few patches that enable the s390 virtio bus to receive
a hotplug add event. This patch implements the qemu side of it, so that new
hotplug events can be submitted to the guest.

Signed-off-by: Alexander Graf <agraf@suse.de>
---
 hw/s390-virtio-bus.c |    9 +++++++++
 hw/s390-virtio-bus.h |    5 +++++
 2 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/hw/s390-virtio-bus.c b/hw/s390-virtio-bus.c
index fe6884d..3ded3f9 100644
--- a/hw/s390-virtio-bus.c
+++ b/hw/s390-virtio-bus.c
@@ -76,6 +76,9 @@ VirtIOS390Bus *s390_virtio_bus_init(ram_addr_t *ram_size)
     bus->dev_offs = bus->dev_page;
     bus->next_ring = bus->dev_page + TARGET_PAGE_SIZE;
 
+    /* Enable hotplugging */
+    _bus->allow_hotplug = 1;
+
     /* Allocate RAM for VirtIO device pages (descriptors, queues, rings) */
     *ram_size += S390_DEVICE_PAGES * TARGET_PAGE_SIZE;
 
@@ -103,6 +106,11 @@ static int s390_virtio_device_init(VirtIOS390Device *dev, VirtIODevice *vdev)
     dev->host_features = vdev->get_features(vdev, dev->host_features);
     s390_virtio_device_sync(dev);
 
+    if (dev->qdev.hotplugged) {
+        kvm_s390_virtio_irq(s390_cpu_addr2state(0), VIRTIO_PARAM_DEV_ADD,
+                            dev->dev_offs);
+    }
+
     return 0;
 }
 
@@ -365,6 +373,7 @@ static void s390_virtio_bus_register_withprop(VirtIOS390DeviceInfo *info)
 {
     info->qdev.init = s390_virtio_busdev_init;
     info->qdev.bus_info = &s390_virtio_bus_info;
+    info->qdev.unplug = qdev_simple_unplug_cb;
 
     assert(info->qdev.size >= sizeof(VirtIOS390Device));
     qdev_register(&info->qdev);
diff --git a/hw/s390-virtio-bus.h b/hw/s390-virtio-bus.h
index 333fea8..7a2f8dc 100644
--- a/hw/s390-virtio-bus.h
+++ b/hw/s390-virtio-bus.h
@@ -32,6 +32,11 @@
 #define VIRTIO_RING_LEN			(TARGET_PAGE_SIZE * 3)
 #define S390_DEVICE_PAGES		256
 
+#define VIRTIO_PARAM_MASK               0xff
+#define VIRTIO_PARAM_VRING_INTERRUPT    0x0
+#define VIRTIO_PARAM_CONFIG_CHANGED     0x1
+#define VIRTIO_PARAM_DEV_ADD            0x2
+
 typedef struct VirtIOS390Device {
     DeviceState qdev;
     ram_addr_t dev_offs;
-- 
1.6.0.2