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authorMichael S. Tsirkin <mst@redhat.com>2014-10-14 23:52:30 (GMT)
committerRusty Russell <rusty@rustcorp.com.au>2014-10-14 23:55:01 (GMT)
commit3569db593081fd88bbd6df21b9b0531873f2042c (patch)
treed16924296b98d3967f31f773c264ad48eef7faf3 /include
parent507613bf31f4bc0a344a1dfc1bc9074fed6eab8f (diff)
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: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'include')
-rw-r--r--include/linux/virtio_config.h17
1 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index e8f8f71..7f4ef66 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -109,6 +109,23 @@ struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
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
const char *virtio_bus_name(struct virtio_device *vdev)
{

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