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Commit 3569db59 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by Rusty Russell
Browse files

virtio: add API to enable VQs early 



virtio spec 0.9.X requires DRIVER_OK to be set before
VQs are used, but some drivers use VQs before probe
function returns.
Since DRIVER_OK is set after probe, this violates the spec.

Even though under virtio 1.0 transitional devices support this
behaviour, we want to make it possible for those early callers to become
spec compliant and eventually support non-transitional devices.

Add API for drivers to call before using VQs.

Sets DRIVER_OK internally.

Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 507613bf

include/linux/virtio_config.h

+17 −0
Original line number Original line Diff line number Diff line
@@ -109,6 +109,23 @@ struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev, 
	return vq;

	return vq;

}

}





/**

 * virtio_device_ready - enable vq use in probe function

 * @vdev: the device

 *

 * Driver must call this to use vqs in the probe function.

 *

 * Note: vqs are enabled automatically after probe returns.

 */

static inline

void virtio_device_ready(struct virtio_device *dev)

{

	unsigned status = dev->config->get_status(dev);



	BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK);

	dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK);

}



static inline

static inline

const char *virtio_bus_name(struct virtio_device *vdev)

const char *virtio_bus_name(struct virtio_device *vdev)

{

{