kernel/linux.git/drivers/net/veth.c, branch v5.15.7

veth: use skb_prepare_for_gro()

2021-07-29T11:18:12+00:00

Leveraging the previous patch we can now avoid orphaning the skb in the veth gro path, allowing correct backpressure. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

veth: create by default nr_possible_cpus queues

2021-07-20T13:11:18+00:00

This allows easier XDP usage. The number of default active queues is not changed: 1 RX and 1 TX so that this does not introduce overhead on the datapath for queue selection. v1 -> v2: - drop the module parameter, force default to nr_possible_cpus - Toke Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

veth: implement support for set_channel ethtool op

2021-07-20T13:11:18+00:00

This change implements the set_channel() ethtool operation, preserving the current defaults values and allowing up set the number of queues in the range set ad device creation time. The update operation tries hard to leave the device in a consistent status in case of errors. RFC v1 -> RFC v2: - don't flip device status on set_channel() - roll-back the changes if possible on error - Jackub Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

veth: factor out initialization helper

2021-07-20T13:11:18+00:00

Extract in simpler helpers the code to enable and disable a range of xdp/napi instance, with the common property that "disable" helpers can't fail. Will be used by the next patch. No functional change intended. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

veth: always report zero combined channels

2021-07-20T13:11:18+00:00

veth get_channel currently reports for channels being both RX/TX and combined. As Jakub noted: """ ethtool man page is relatively clear, unfortunately the kernel code is not and few read the man page. A channel is approximately an IRQ, not a queue, and IRQ can't be dedicated and combined simultaneously """ This patch changes the information exposed by veth_get_channels, setting max_combined to zero, being more consistent with the above statement. The ethtool_channels is always cleared by the caller, we just need to avoid setting the 'combined' fields. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

veth: check for NAPI instead of xdp_prog before xmit of XDP frame

2021-04-16T22:42:07+00:00

The recent patch that tied enabling of veth NAPI to the GRO flag also has the nice side effect that a veth device can be the target of an XDP_REDIRECT without an XDP program needing to be loaded on the peer device. However, the patch adding this extra NAPI mode didn't actually change the check in veth_xdp_xmit() to also look at the new NAPI pointer, so let's fix that. Fixes: 6788fa154546 ("veth: allow enabling NAPI even without XDP") Signed-off-by: Toke Høiland-Jørgensen Acked-by: Jesper Dangaard Brouer Acked-by: Paolo Abeni Signed-off-by: David S. Miller

veth: refine napi usage

2021-04-11T23:39:28+00:00

After the previous patch, when enabling GRO, locally generated TCP traffic experiences some measurable overhead, as it traverses the GRO engine without any chance of aggregation. This change refine the NAPI receive path admission test, to avoid unnecessary GRO overhead in most scenarios, when GRO is enabled on a veth peer. Only skbs that are eligible for aggregation enter the GRO layer, the others will go through the traditional receive path. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

veth: allow enabling NAPI even without XDP

2021-04-11T23:39:28+00:00

Currently the veth device has the GRO feature bit set, even if no GRO aggregation is possible with the default configuration, as the veth device does not hook into the GRO engine. Flipping the GRO feature bit from user-space is a no-op, unless XDP is enabled. In such scenario GRO could actually take place, but TSO is forced to off on the peer device. This change allow user-space to really control the GRO feature, with no need for an XDP program. The GRO feature bit is now cleared by default - so that there are no user-visible behavior changes with the default configuration. When the GRO bit is set, the per-queue NAPI instances are initialized and registered. On xmit, when napi instances are available, we try to use them. Some additional checks are in place to ensure we initialize/delete NAPIs only when needed in case of overlapping XDP and GRO configuration changes. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

veth: use skb_orphan_partial instead of skb_orphan

2021-04-11T23:39:28+00:00

As described by commit 9c4c325252c5 ("skbuff: preserve sock reference when scrubbing the skb."), orphaning a skb in the TX path will cause OoO. Let's use skb_orphan_partial() instead of skb_orphan(), so that we keep the sk around for queue's selection sake and we still avoid the problem fixed with commit 4bf9ffa0fb57 ("veth: Orphan skb before GRO") Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller

veth: Implement ethtool's get_channels() callback

2021-03-30T16:24:39+00:00

Libbpf's xsk part calls get_channels() API to retrieve the queue count of the underlying driver so that XSKMAP is sized accordingly. Implement that in veth so multi queue scenarios can work properly. Signed-off-by: Maciej Fijalkowski Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20210329224316.17793-14-maciej.fijalkowski@intel.com