Thread (5 messages) 5 messages, 2 authors, 15d ago

Re: [PATCH 1/2] bpf: preserve rx_queue_index across XDP redirects

From: bot+bpf-ci@kernel.org
Date: 2026-06-19 20:50:42
Also in: bpf, lkml

Store rx_queue_index in struct xdp_frame during xdp_buff to
xdp_frame conversion and restore it when rebuilding xdp_rxq_info
for cpumap and devmap execution paths.
This preserves ingress RX queue information for XDP programs
executed after redirect, allowing access to the original
rx_queue_index instead of losing queue context.
Also propagate rx_queue_index for zero-copy XDP frame conversion.
Signed-off-by: Siddharth_Cibi <redacted>
This looks like a fix for the cpumap path, where the synthetic
xdp_rxq_info was previously built without a queue_index, leaving the
placeholder:

kernel/bpf/cpumap.c:cpu_map_bpf_prog_run_xdp() {
	rxq.dev = xdpf->dev_rx;
	rxq.mem.type = xdpf->mem_type;
	/* TODO: report queue_index to xdp_rxq_info */
	...
}

That synthetic xdp_rxq_info, with the missing queue_index and the TODO,
came in when cpu_map_bpf_prog_run_xdp() was added.  Should this carry:

  Fixes: 9216477449f3 ("bpf: cpumap: Add the possibility to attach an eBPF program to cpumap")

The devmap path (dev_map_bpf_prog_run) shares the same missing
queue_index, which was added in fbee97feed9b ("bpf: Add support to attach
bpf program to a devmap entry").


---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md

CI run summary: https://github.com/kernel-patches/bpf/actions/runs/27846609854
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