Re: [PATCH net-next v5 1/4] virtio_ring: enable premapped mode whatever use_dma_api

[Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>]

Hi, guys, I have a fix patch for this.
Could anybody test it?

Thanks.

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index af474cc191d0..426d68c2d01d 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2492,13 +2492,15 @@ static unsigned int get_mergeable_buf_len(struct receive_queue *rq,
 {
        struct virtnet_info *vi = rq->vq->vdev->priv;
        const size_t hdr_len = vi->hdr_len;
-       unsigned int len;
+       unsigned int len, max_len;
+
+       max_len = PAGE_SIZE - ALIGN(sizeof(struct virtnet_rq_dma), L1_CACHE_BYTES);

        if (room)
-               return PAGE_SIZE - room;
+               return max_len - room;

        len = hdr_len + clamp_t(unsigned int, ewma_pkt_len_read(avg_pkt_len),
-                               rq->min_buf_len, PAGE_SIZE - hdr_len);
+                               rq->min_buf_len, max_len - hdr_len);

        return ALIGN(len, L1_CACHE_BYTES);
 }