Re: [PATCH V8 00/19] virtio_ring in order support

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Oct 20, 2025 at 03:09:44PM +0800, Jason Wang wrote:
> Hello all:
> 
> This sereis tries to implement the VIRTIO_F_IN_ORDER to
> virtio_ring. This is done by introducing virtqueue ops so we can
> implement separate helpers for different virtqueue layout/features
> then the in-order were implemented on top.
> 
> Tests shows 2%-19% imporvment with packed virtqueue PPS with KVM guest
> vhost-net/testpmd on the host.

This is much improved thank you!
There are some coding style comments worth addressing but
I think we are almost there.

> Changes since v7:
> 
> - Rebase on vhost.git linux-next branch
> - Tweak the comment to explain the usage of free_head
> 
> Changes since V6:
> 
> - Rebase on vhost.git linux-next branch
> - Fix poking packed virtqueue in more_used_split_in_order()
> - Fix calling detach_buf_packed_in_order() unconditonally in
>   virtqueue_detach_unused_buf_packed()
> - Typo and indentation fixes
> - Fix wrong changelog of patch 7
> 
> Changes since V5:
> 
> - rebase on vhost.git linux-next branch
> - reorder the total_len to reduce memory comsuming
> 
> Changes since V4:
> 
> - Fix build error when DEBUG is enabled
> - Fix function duplications
> - Remove unnecessary new lines
> 
> Changes since V3:
> 
> - Re-benchmark with the recent vhost-net in order support
> - Rename the batched used id and length
> - Other minor tweaks
> 
> Changes since V2:
> 
> - Fix build warning when DEBUG is enabled
> 
> Changes since V1:
> 
> - use const global array of function pointers to avoid indirect
>   branches to eliminate retpoline when mitigation is enabled
> - fix used length calculation when processing used ids in a batch
> - fix sparse warnings
> 
> Jason Wang (19):
>   virtio_ring: rename virtqueue_reinit_xxx to virtqueue_reset_xxx()
>   virtio_ring: switch to use vring_virtqueue in virtqueue_poll variants
>   virtio_ring: unify logic of virtqueue_poll() and more_used()
>   virtio_ring: switch to use vring_virtqueue for virtqueue resize
>     variants
>   virtio_ring: switch to use vring_virtqueue for virtqueue_kick_prepare
>     variants
>   virtio_ring: switch to use vring_virtqueue for virtqueue_add variants
>   virtio: switch to use vring_virtqueue for virtqueue_get variants
>   virtio_ring: switch to use vring_virtqueue for enable_cb_prepare
>     variants
>   virtio_ring: use vring_virtqueue for enable_cb_delayed variants
>   virtio_ring: switch to use vring_virtqueue for disable_cb variants
>   virtio_ring: switch to use vring_virtqueue for detach_unused_buf
>     variants
>   virtio_ring: switch to use unsigned int for virtqueue_poll_packed()
>   virtio_ring: introduce virtqueue ops
>   virtio_ring: determine descriptor flags at one time
>   virtio_ring: factor out core logic of buffer detaching
>   virtio_ring: factor out core logic for updating last_used_idx
>   virtio_ring: factor out split indirect detaching logic
>   virtio_ring: factor out split detaching logic
>   virtio_ring: add in order support
> 
>  drivers/virtio/virtio_ring.c | 905 ++++++++++++++++++++++++++---------
>  1 file changed, 692 insertions(+), 213 deletions(-)
> 
> -- 
> 2.31.1