[PATCH RFC v2 1/4] virtio: add API to detect legacy devices

From: Michael S. Tsirkin
Date: Thu Dec 04 2014 - 13:44:55 EST


transports need to be able to detect legacy-only
devices (ATM balloon only) to use legacy path
to drive them.

Add a core API to do just that.
The implementation just blacklists balloon:
not too pretty, but let's not over-engineer.

Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Acked-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>
---
include/linux/virtio.h | 2 ++
drivers/virtio/virtio.c | 6 ++++++
2 files changed, 8 insertions(+)

diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 2bbf626..d666bcb 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -108,6 +108,8 @@ struct virtio_device {
void *priv;
};

+bool virtio_device_is_legacy_only(struct virtio_device_id id);
+
static inline struct virtio_device *dev_to_virtio(struct device *_dev)
{
return container_of(_dev, struct virtio_device, dev);
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index fa6b75d..6b4c1113 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -267,6 +267,12 @@ static struct bus_type virtio_bus = {
.remove = virtio_dev_remove,
};

+bool virtio_device_is_legacy_only(struct virtio_device_id id)
+{
+ return id.device == VIRTIO_ID_BALLOON;
+}
+EXPORT_SYMBOL_GPL(register_virtio_driver);
+
int register_virtio_driver(struct virtio_driver *driver)
{
/* Catch this early. */
--
MST

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/