Re: [PATCH V3 00/19] virtio_ring in order support

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

On Mon, Jun 16, 2025 at 04:24:58PM +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 3%-5% imporvment with packed virtqueue PPS with KVM guest
> testpmd on the host.

Thanks very much. I think this is going in the right direction,
though some things to improve remain.
Sent comments, thanks!


> 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
> 
> Please review.
> 
> Thanks
> 
> 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_add 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: use u16 for last_used_idx in virtqueue_poll_split()
>   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 | 896 ++++++++++++++++++++++++++---------
>  1 file changed, 684 insertions(+), 212 deletions(-)
> 
> -- 
> 2.34.1