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)

2 files changed, 41 insertions, 23 deletions

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 0fa73b4d18b0..26b278264796 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -204,6 +204,9 @@ static int balloon(void *_vballoon)
 static int virtballoon_probe(struct virtio_device *vdev)
 {
         struct virtio_balloon *vb;
+        struct virtqueue *vqs[2];
+        vq_callback_t *callbacks[] = { balloon_ack, balloon_ack };
+        const char *names[] = { "inflate", "deflate" };
         int err;
 
         vdev->priv = vb = kmalloc(sizeof(*vb), GFP_KERNEL);
@@ -218,22 +221,17 @@ static int virtballoon_probe(struct virtio_device *vdev)
         vb->vdev = vdev;
 
         /* We expect two virtqueues. */
-        vb->inflate_vq = vdev->config->find_vq(vdev, 0, balloon_ack, "inflate");
-        if (IS_ERR(vb->inflate_vq)) {
-                err = PTR_ERR(vb->inflate_vq);
+        err = vdev->config->find_vqs(vdev, 2, vqs, callbacks, names);
+        if (err)
                 goto out_free_vb;
-        }
 
-        vb->deflate_vq = vdev->config->find_vq(vdev, 1, balloon_ack, "deflate");
-        if (IS_ERR(vb->deflate_vq)) {
-                err = PTR_ERR(vb->deflate_vq);
-                goto out_del_inflate_vq;
-        }
+        vb->inflate_vq = vqs[0];
+        vb->deflate_vq = vqs[1];
 
         vb->thread = kthread_run(balloon, vb, "vballoon");
         if (IS_ERR(vb->thread)) {
                 err = PTR_ERR(vb->thread);
-                goto out_del_deflate_vq;
+                goto out_del_vqs;
         }
 
         vb->tell_host_first
@@ -241,10 +239,8 @@ static int virtballoon_probe(struct virtio_device *vdev)
 
         return 0;
 
-out_del_deflate_vq:
-        vdev->config->del_vq(vb->deflate_vq);
-out_del_inflate_vq:
-        vdev->config->del_vq(vb->inflate_vq);
+out_del_vqs:
+        vdev->config->del_vqs(vdev);
 out_free_vb:
         kfree(vb);
 out:
@@ -264,8 +260,7 @@ static void virtballoon_remove(struct virtio_device *vdev)
         /* Now we reset the device so we can clean up the queues. */
         vdev->config->reset(vdev);
 
-        vdev->config->del_vq(vb->deflate_vq);
-        vdev->config->del_vq(vb->inflate_vq);
+        vdev->config->del_vqs(vdev);
         kfree(vb);
 }
 
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index be4047abd5ba..027f13fbe493 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -276,11 +276,7 @@ static void vp_del_vq(struct virtqueue *vq)
 {
         struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
         struct virtio_pci_vq_info *info = vq->priv;
-        unsigned long flags, size;
-
-        spin_lock_irqsave(&vp_dev->lock, flags);
-        list_del(&info->node);
-        spin_unlock_irqrestore(&vp_dev->lock, flags);
+        unsigned long size;
 
         vring_del_virtqueue(vq);
 
@@ -293,14 +289,41 @@ static void vp_del_vq(struct virtqueue *vq)
         kfree(info);
 }
 
+static void vp_del_vqs(struct virtio_device *vdev)
+{
+        struct virtqueue *vq, *n;
+
+        list_for_each_entry_safe(vq, n, &vdev->vqs, list)
+                vp_del_vq(vq);
+}
+
+static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+                       struct virtqueue *vqs[],
+                       vq_callback_t *callbacks[],
+                       const char *names[])
+{
+        int i;
+
+        for (i = 0; i < nvqs; ++i) {
+                vqs[i] = vp_find_vq(vdev, i, callbacks[i], names[i]);
+                if (IS_ERR(vqs[i]))
+                        goto error;
+        }
+        return 0;
+
+error:
+        vp_del_vqs(vdev);
+        return PTR_ERR(vqs[i]);
+}
+
 static struct virtio_config_ops virtio_pci_config_ops = {
         .get            = vp_get,
         .set            = vp_set,
         .get_status     = vp_get_status,
         .set_status     = vp_set_status,
         .reset          = vp_reset,
-        .find_vq        = vp_find_vq,
-        .del_vq         = vp_del_vq,
+        .find_vqs       = vp_find_vqs,
+        .del_vqs        = vp_del_vqs,
         .get_features   = vp_get_features,
         .finalize_features = vp_finalize_features,
 };