similar to: [PATCH net-next V2 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 Please review. Thanks Jason Wang (5): virtio_ring: allow to store zero as the ctx virtio-net: pack headroom into ctx for mergeable buffer virtio-net: switch to use new ctx API for small buffer virtio-net: do not reset during XDP set virtio-net: switch off offloads

Hi: This series brings two optimizations for virtio-net XDP: - avoid reset during XDP set - turn off offloads on demand Please review. Thanks Jason Wang (5): virtio_ring: allow to store zero as the ctx virtio-net: pack headroom into ctx for mergeable buffer virtio-net: switch to use new ctx API for small buffer virtio-net: do not reset during XDP set virtio-net: switch off offloads

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

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

On Wed, Jul 19, 2017 at 04:54:49PM +0800, Jason Wang wrote: > Current XDP implementation wants guest offloads feature to be disabled > on 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 disabling the offloads on demand through control guest > offloads. Guest offloads will be disabled

On Wed, Jul 19, 2017 at 04:54:49PM +0800, Jason Wang wrote: > Current XDP implementation wants guest offloads feature to be disabled > on 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 disabling the offloads on demand through control guest > offloads. Guest offloads will be disabled

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

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

We try to disable NAPI to prevent a single XDP TX queue being used by multiple cpus. But we don't check if device is up (NAPI is enabled), this could result stall because of infinite wait in napi_disable(). Fixing this by checking device state through netif_running() before. Fixes: 4941d472bf95b ("virtio-net: do not reset during XDP set") Signed-off-by: Jason Wang <jasowang at

We try to disable NAPI to prevent a single XDP TX queue being used by multiple cpus. But we don't check if device is up (NAPI is enabled), this could result stall because of infinite wait in napi_disable(). Fixing this by checking device state through netif_running() before. Fixes: 4941d472bf95b ("virtio-net: do not reset during XDP set") Signed-off-by: Jason Wang <jasowang at

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

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 by: - packing headroom into receive buffer ctx - check the headroom during XDP, and

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

Current XDP implementation want guest offloads feature to be disabled on qemu cli. 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 the offloads on demand through control guest offloads. Guest offloads will be disabled and enabled on demand on XDP set. Signed-off-by: Jason Wang <jasowang at

Current XDP implementation wants guest offloads feature to be disabled on 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 disabling the offloads on demand through control guest offloads. Guest offloads will be disabled and enabled on demand on XDP set. Signed-off-by: Jason Wang <jasowang at