virtio_net: disable premapped mode by default

Now, the premapped mode encounters some problem.

    http://lore.kernel.org/all/8b20cc28-45a9-4643-8e87-ba164a540c0a@oracle.com

So we disable the premapped mode by default.
We can re-enable it in the future.

Fixes: f9dac92ba908 ("virtio_ring: enable premapped mode whatever use_dma_api")
Reported-by: "Si-Wei Liu" <si-wei.liu@oracle.com>
Closes: http://lore.kernel.org/all/8b20cc28-45a9-4643-8e87-ba164a540c0a@oracle.com
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Takero Funaki <flintglass@gmail.com>
Link: https://patch.msgid.link/20240906123137.108741-4-xuanzhuo@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 1cf80648f82a49377d2a7429523f77c139c6194f..5a1c1ec5a64b8ebfba3bf9764d2058ef897ed0ae 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -977,22 +977,6 @@ static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp)
        return buf;
 }
 
-static void virtnet_rq_set_premapped(struct virtnet_info *vi)
-{
-       int i;
-
-       /* disable for big mode */
-       if (!vi->mergeable_rx_bufs && vi->big_packets)
-               return;
-
-       for (i = 0; i < vi->max_queue_pairs; i++) {
-               if (virtqueue_set_dma_premapped(vi->rq[i].vq))
-                       continue;
-
-               vi->rq[i].do_dma = true;
-       }
-}
-
 static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf)
 {
        struct virtnet_info *vi = vq->vdev->priv;
@@ -6105,8 +6089,6 @@ static int init_vqs(struct virtnet_info *vi)
        if (ret)
                goto err_free;
 
-       virtnet_rq_set_premapped(vi);
-
        cpus_read_lock();
        virtnet_set_affinity(vi);
        cpus_read_unlock();