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)

1 files changed, 34 insertions, 2 deletions

diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
index 4babed899d59..e082cdac88b4 100644
--- a/drivers/lguest/lguest_device.c
+++ b/drivers/lguest/lguest_device.c
@@ -313,6 +313,38 @@ static void lg_del_vq(struct virtqueue *vq)
         kfree(lvq);
 }
 
+static void lg_del_vqs(struct virtio_device *vdev)
+{
+        struct virtqueue *vq, *n;
+
+        list_for_each_entry_safe(vq, n, &vdev->vqs, list)
+                lg_del_vq(vq);
+}
+
+static int lg_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+                       struct virtqueue *vqs[],
+                       vq_callback_t *callbacks[],
+                       const char *names[])
+{
+        struct lguest_device *ldev = to_lgdev(vdev);
+        int i;
+
+        /* We must have this many virtqueues. */
+        if (nvqs > ldev->desc->num_vq)
+                return -ENOENT;
+
+        for (i = 0; i < nvqs; ++i) {
+                vqs[i] = lg_find_vq(vdev, i, callbacks[i], names[i]);
+                if (IS_ERR(vqs[i]))
+                        goto error;
+        }
+        return 0;
+
+error:
+        lg_del_vqs(vdev);
+        return PTR_ERR(vqs[i]);
+}
+
 /* The ops structure which hooks everything together. */
 static struct virtio_config_ops lguest_config_ops = {
         .get_features = lg_get_features,
@@ -322,8 +354,8 @@ static struct virtio_config_ops lguest_config_ops = {
         .get_status = lg_get_status,
         .set_status = lg_set_status,
         .reset = lg_reset,
-        .find_vq = lg_find_vq,
-        .del_vq = lg_del_vq,
+        .find_vqs = lg_find_vqs,
+        .del_vqs = lg_del_vqs,
 };
 
 /* The root device for the lguest virtio devices.  This makes them appear as