[PATCH] virtio: Remove virtio device during shutdown

[Fam Zheng <famz@redhat.com>]

Currently shutdown is nop for virtio devices, but the core code could
remove things behind us such as MSI-X handler etc. For example in the
case of virtio-scsi-pci, the device may still try to send interupts,
which will be on IRQ lines seeing MSI-X disabled. Those interrupts will
be unhandled, and may cause flood.

Remove the device in "shutdown" callback to allow device drivers clean
up things.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 drivers/virtio/virtio.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 5ce2aa4..12f1f1e 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -269,6 +269,19 @@ static int virtio_dev_remove(struct device *_d)
 	return 0;
 }
 
+static void virtio_dev_shutdown(struct device *_d)
+{
+	struct virtio_device *dev = dev_to_virtio(_d);
+	struct virtio_driver *drv = drv_to_virtio(dev->dev.driver);
+
+	virtio_config_disable(dev);
+
+	drv->remove(dev);
+
+	/* Driver should have reset device. */
+	WARN_ON_ONCE(dev->config->get_status(dev));
+}
+
 static struct bus_type virtio_bus = {
 	.name  = "virtio",
 	.match = virtio_dev_match,
@@ -276,6 +289,7 @@ static struct bus_type virtio_bus = {
 	.uevent = virtio_uevent,
 	.probe = virtio_dev_probe,
 	.remove = virtio_dev_remove,
+	.shutdown = virtio_dev_shutdown,
 };
 
 bool virtio_device_is_legacy_only(struct virtio_device_id id)
-- 
1.9.3