On Mon, Sep 22, 2025 at 2:40 AM Michael S. Tsirkin <[email protected]> wrote: > > On Fri, Sep 19, 2025 at 03:31:49PM +0800, Jason Wang wrote: > > Let's determine the last descriptor by counting the number of sg. This > > would be consistent with packed virtqueue implementation and ease the > > future in-order implementation. > > > > Acked-by: Eugenio Pérez <[email protected]> > > Reviewed-by: Xuan Zhuo <[email protected]> > > Signed-off-by: Jason Wang <[email protected]> > > --- > > drivers/virtio/virtio_ring.c | 21 ++++++++------------- > > 1 file changed, 8 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > > index 1045c553ee65..0949675a3d12 100644 > > --- a/drivers/virtio/virtio_ring.c > > +++ b/drivers/virtio/virtio_ring.c > > @@ -574,7 +574,7 @@ static inline int virtqueue_add_split(struct > > vring_virtqueue *vq, > > struct vring_desc_extra *extra; > > struct scatterlist *sg; > > struct vring_desc *desc; > > - unsigned int i, n, avail, descs_used, prev, err_idx; > > + unsigned int i, n, avail, descs_used, err_idx, c = 0; > > int head; > > bool indirect; > > > > @@ -631,6 +631,7 @@ static inline int virtqueue_add_split(struct > > vring_virtqueue *vq, > > } > > > > for (n = 0; n < out_sgs; n++) { > > + sg = sgs[n]; > > for (sg = sgs[n]; sg; sg = sg_next(sg)) { > > dma_addr_t addr; > > u32 len; > > @@ -638,12 +639,12 @@ static inline int virtqueue_add_split(struct > > vring_virtqueue *vq, > > if (vring_map_one_sg(vq, sg, DMA_TO_DEVICE, &addr, > > &len, premapped)) > > goto unmap_release; > > > > - prev = i; > > /* Note that we trust indirect descriptor > > * table since it use stream DMA mapping. > > */ > > i = virtqueue_add_desc_split(vq, desc, extra, i, > > addr, len, > > - VRING_DESC_F_NEXT, > > + ++c == total_sg ? > > + 0 : VRING_DESC_F_NEXT, > > I would indent this line a bit more to the right - it is a continuation, > after all. >
Fixed. Thanks
