virtio: find_vqs/del_vqs virtio operations
This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations,
and updates all drivers. This is needed for MSI support, because MSI
needs to know the total number of vectors upfront.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ lguest/9p compile fixes)
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 9fae274..4cd290c 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -29,6 +29,7 @@
#define VIRTIO_F_NOTIFY_ON_EMPTY 24
#ifdef __KERNEL__
+#include <linux/err.h>
#include <linux/virtio.h>
/**
@@ -49,16 +50,26 @@
* @set_status: write the status byte
* vdev: the virtio_device
* status: the new status byte
+ * @request_vqs: request the specified number of virtqueues
+ * vdev: the virtio_device
+ * max_vqs: the max number of virtqueues we want
+ * If supplied, must call before any virtqueues are instantiated.
+ * To modify the max number of virtqueues after request_vqs has been
+ * called, call free_vqs and then request_vqs with a new value.
+ * @free_vqs: cleanup resources allocated by request_vqs
+ * vdev: the virtio_device
+ * If supplied, must call after all virtqueues have been deleted.
* @reset: reset the device
* vdev: the virtio device
* After this, status and feature negotiation must be done again
- * @find_vq: find a virtqueue and instantiate it.
+ * @find_vqs: find virtqueues and instantiate them.
* vdev: the virtio_device
- * index: the 0-based virtqueue number in case there's more than one.
- * callback: the virtqueue callback
- * name: the virtqueue name (mainly for debugging)
- * Returns the new virtqueue or ERR_PTR() (eg. -ENOENT).
- * @del_vq: free a virtqueue found by find_vq().
+ * nvqs: the number of virtqueues to find
+ * vqs: on success, includes new virtqueues
+ * callbacks: array of callbacks, for each virtqueue
+ * names: array of virtqueue names (mainly for debugging)
+ * Returns 0 on success or error status
+ * @del_vqs: free virtqueues found by find_vqs().
* @get_features: get the array of feature bits for this device.
* vdev: the virtio_device
* Returns the first 32 feature bits (all we currently need).
@@ -67,6 +78,7 @@
* This gives the final feature bits for the device: it can change
* the dev->feature bits if it wants.
*/
+typedef void vq_callback_t(struct virtqueue *);
struct virtio_config_ops
{
void (*get)(struct virtio_device *vdev, unsigned offset,
@@ -76,11 +88,11 @@
u8 (*get_status)(struct virtio_device *vdev);
void (*set_status)(struct virtio_device *vdev, u8 status);
void (*reset)(struct virtio_device *vdev);
- struct virtqueue *(*find_vq)(struct virtio_device *vdev,
- unsigned index,
- void (*callback)(struct virtqueue *),
- const char *name);
- void (*del_vq)(struct virtqueue *vq);
+ int (*find_vqs)(struct virtio_device *, unsigned nvqs,
+ struct virtqueue *vqs[],
+ vq_callback_t *callbacks[],
+ const char *names[]);
+ void (*del_vqs)(struct virtio_device *);
u32 (*get_features)(struct virtio_device *vdev);
void (*finalize_features)(struct virtio_device *vdev);
};
@@ -128,5 +140,18 @@
vdev->config->get(vdev, offset, buf, len);
return 0;
}
+
+static inline
+struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
+ vq_callback_t *c, const char *n)
+{
+ vq_callback_t *callbacks[] = { c };
+ const char *names[] = { n };
+ struct virtqueue *vq;
+ int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names);
+ if (err < 0)
+ return ERR_PTR(err);
+ return vq;
+}
#endif /* __KERNEL__ */
#endif /* _LINUX_VIRTIO_CONFIG_H */