similar to: [RFC PATCH] virtio_net: XDP support for adjust_head

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

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 17-02-15 01:08 AM, Jason Wang wrote: > 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

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

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. Other complaints are, the complex linearize logic and EWMA estimation may increase the possibility of linearizing. Signed-off-by:

On Thu, Mar 01, 2018 at 11:19:04AM +0800, Jason Wang wrote: > 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. Other complaints are, the > complex linearize logic

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

There's no need to duplicate page get logic in each action. So this patch tries to get page and calculate the offset before processing XDP actions, and undo them when meet errors (we don't care the performance on errors). This will be used for factoring out XDP logic. Signed-off-by: Jason Wang <jasowang at redhat.com> --- drivers/net/tun.c | 37 ++++++++++++++++---------------------

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

On 2018?09?07? 01:14, Michael S. Tsirkin wrote: > On Thu, Sep 06, 2018 at 12:05:19PM +0800, Jason Wang wrote: >> There's no need to duplicate page get logic in each action. So this >> patch tries to get page and calculate the offset before processing XDP >> actions, and undo them when meet errors (we don't care the performance >> on errors). This will be used for

On Thu, Sep 06, 2018 at 12:05:19PM +0800, Jason Wang wrote: > There's no need to duplicate page get logic in each action. So this > patch tries to get page and calculate the offset before processing XDP > actions, and undo them when meet errors (we don't care the performance > on errors). This will be used for factoring out XDP logic. > > Signed-off-by: Jason Wang

On Thu, Sep 06, 2018 at 12:05:19PM +0800, Jason Wang wrote: > There's no need to duplicate page get logic in each action. So this > patch tries to get page and calculate the offset before processing XDP > actions, and undo them when meet errors (we don't care the performance > on errors). This will be used for factoring out XDP logic. > > Signed-off-by: Jason Wang

Commit f600b6905015 ("virtio_net: Add XDP support") leaves the case of small receive buffer untouched. This will confuse the user who want to set XDP but use small buffers. Other than forbid XDP in small buffer mode, let's make it work. XDP then can only work at skb->data since virtio-net create skbs during refill, this is sub optimal which could be optimized in the future. Cc:

On 2017?07?19? 04:07, Michael S. Tsirkin wrote: > 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

On Fri, Mar 02, 2018 at 05:29:14PM +0800, Jason Wang wrote: > 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

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