[PATCH vhost v13 01/12] virtio_ring: check use_dma_api before unmap desc for indirect
From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Date: 2023-08-10 12:31:08
Also in:
bpf, virtualization
Subsystem:
the rest, virtio core · Maintainers:
Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Inside detach_buf_split(), if use_dma_api is false, vring_unmap_one_split_indirect will be called many times, but actually nothing is done. So this patch check use_dma_api firstly. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Acked-by: Jason Wang <jasowang@redhat.com> --- drivers/virtio/virtio_ring.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index c5310eaf8b46..f8754f1d64d3 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c@@ -774,8 +774,10 @@ static void detach_buf_split(struct vring_virtqueue *vq, unsigned int head, VRING_DESC_F_INDIRECT)); BUG_ON(len == 0 || len % sizeof(struct vring_desc)); - for (j = 0; j < len / sizeof(struct vring_desc); j++) - vring_unmap_one_split_indirect(vq, &indir_desc[j]); + if (vq->use_dma_api) { + for (j = 0; j < len / sizeof(struct vring_desc); j++) + vring_unmap_one_split_indirect(vq, &indir_desc[j]); + } kfree(indir_desc); vq->split.desc_state[head].indir_desc = NULL;
--
2.32.0.3.g01195cf9f