similar to: [PATCH net-next 0/5] refine virtio-net XDP

Hi: This series brings two optimizations for virtio-net XDP: - avoid reset during XDP set - turn off offloads on demand Changes from V1: - Various tweaks on commit logs and comments - Use virtnet_napi_enable() when enabling NAPI on XDP set - Copy the small buffer packet only if xdp_headroom is smaller than required Please review. Thanks Jason Wang (5): virtio_ring: allow to store zero as

Hi: This series brings two optimizations for virtio-net XDP: - avoid reset during XDP set - turn off offloads on demand Changes from V1: - Various tweaks on commit logs and comments - Use virtnet_napi_enable() when enabling NAPI on XDP set - Copy the small buffer packet only if xdp_headroom is smaller than required Please review. Thanks Jason Wang (5): virtio_ring: allow to store zero as

On Mon, Jul 17, 2017 at 08:44:00PM +0800, Jason Wang wrote: > We used to reset during XDP set, the main reason is we need allocate > extra headroom for header adjustment but there's no way to know the > headroom of exist receive buffer. This works buy maybe complex and may > cause the network down for a while which is bad for user > experience. So this patch tries to avoid this

On Mon, Jul 17, 2017 at 08:44:00PM +0800, Jason Wang wrote: > We used to reset during XDP set, the main reason is we need allocate > extra headroom for header adjustment but there's no way to know the > headroom of exist receive buffer. This works buy maybe complex and may > cause the network down for a while which is bad for user > experience. So this patch tries to avoid this

Hi: This series tries to re-enable XDP_REDIRECT for mergeable buffer which was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). Main concerns are: - not enough tailroom was reserved which breaks cpumap - complex logic like EWMA and linearizing during XDP processing Fix those by: - reserve enough tailroom during refill - disable EWMA

Hi: This series tries to re-enable XDP_REDIRECT for mergeable buffer which was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). Main concerns are: - not enough tailroom was reserved which breaks cpumap - complex logic like EWMA and linearizing during XDP processing Fix those by: - reserve enough tailroom during refill - disable EWMA

Due to historical reasons, the implementation of XDP in virtio-net is relatively chaotic. For example, the processing of XDP actions has two copies of similar code. Such as page, xdp_page processing, etc. The purpose of this patch set is to refactor these code. Reduce the difficulty of subsequent maintenance. Subsequent developers will not introduce new bugs because of some complex logical

Due to historical reasons, the implementation of XDP in virtio-net is relatively chaotic. For example, the processing of XDP actions has two copies of similar code. Such as page, xdp_page processing, etc. The purpose of this patch set is to refactor these code. Reduce the difficulty of subsequent maintenance. Subsequent developers will not introduce new bugs because of some complex logical

Due to historical reasons, the implementation of XDP in virtio-net is relatively chaotic. For example, the processing of XDP actions has two copies of similar code. Such as page, xdp_page processing, etc. The purpose of this patch set is to refactor these code. Reduce the difficulty of subsequent maintenance. Subsequent developers will not introduce new bugs because of some complex logical

XDP_REDIRECT support for mergeable buffer was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). This is because we don't reserve enough tailroom for struct skb_shared_info which breaks XDP assumption. So this patch fixes this by reserving enough tailroom and using fixed size of rx buffer. Signed-off-by: Jason Wang <jasowang at

XDP_REDIRECT support for mergeable buffer was removed since commit 7324f5399b06 ("virtio_net: disable XDP_REDIRECT in receive_mergeable() case"). This is because we don't reserve enough tailroom for struct skb_shared_info which breaks XDP assumption. So this patch fixes this by reserving enough tailroom and using fixed size of rx buffer. Signed-off-by: Jason Wang <jasowang at

what's needed is ability to store the headroom there. virtio-net: switch to use ctx API for small buffers Use ctx API to store headroom for small buffers. Following patches will retrieve this info and use it for XDP. On Mon, Jul 17, 2017 at 08:43:59PM +0800, Jason Wang wrote: > Switch to use ctx API for small buffer, this is need for avoiding > reset on XDP. > > Signed-off-by:

what's needed is ability to store the headroom there. virtio-net: switch to use ctx API for small buffers Use ctx API to store headroom for small buffers. Following patches will retrieve this info and use it for XDP. On Mon, Jul 17, 2017 at 08:43:59PM +0800, Jason Wang wrote: > Switch to use ctx API for small buffer, this is need for avoiding > reset on XDP. > > Signed-off-by:

We tried to reserve space for vnet header before xdp.data_hard_start. But this is useless since the packet could be modified by XDP which may invalidate the information stored in the header and there's no way for XDP to know the existence of the vnet header currently. So let's just not reserve space for vnet header in this case. Cc: Jesper Dangaard Brouer <brouer at redhat.com>

We tried to reserve space for vnet header before xdp.data_hard_start. But this is useless since the packet could be modified by XDP which may invalidate the information stored in the header and there's no way for XDP to know the existence of the vnet header currently. So let's just not reserve space for vnet header in this case. Cc: Jesper Dangaard Brouer <brouer at redhat.com>

On Mon, Jul 17, 2017 at 08:44:01PM +0800, Jason Wang wrote: > Current XDP implementation want guest offloads feature to be disabled s/want/wants/ > on qemu cli. on the device. > This is inconvenient and means guest can't benefit from > offloads if XDP is not used. This patch tries to address this > limitation by disable disabling > the offloads on demand through control

On Mon, Jul 17, 2017 at 08:44:01PM +0800, Jason Wang wrote: > Current XDP implementation want guest offloads feature to be disabled s/want/wants/ > on qemu cli. on the device. > This is inconvenient and means guest can't benefit from > offloads if XDP is not used. This patch tries to address this > limitation by disable disabling > the offloads on demand through control

Separating the logic of preparation for xdp from receive_mergeable. The purpose of this is to simplify the logic of execution of XDP. The main logic here is that when headroom is insufficient, we need to allocate a new page and calculate offset. It should be noted that if there is new page, the variable page will refer to the new page. Signed-off-by: Xuan Zhuo <xuanzhuo at

? 2023/3/28 20:04, Xuan Zhuo ??: > Separating the logic of preparation for xdp from receive_mergeable. > > The purpose of this is to simplify the logic of execution of XDP. > > The main logic here is that when headroom is insufficient, we need to > allocate a new page and calculate offset. It should be noted that if > there is new page, the variable page will refer to the new

We set queues before reset which will cause a crash[1]. This is because is_xdp_raw_buffer_queue() depends on the old xdp queue pairs number to do the correct detection. So fix this by: - set queues after reset, to keep the old vi->curr_queue_pairs. (in fact setting queues before reset does not works since after feature set, all queue pairs were enabled by default during reset). - change