[PATCH v2 bpf-next] xdp: report rx queue index in xdp_frame

[Lorenzo Bianconi <lorenzo@kernel.org>]

Report rx queue index in xdp_frame according to the xdp_buff xdp_rxq_info
pointer. xdp_frame queue_index is currently used in cpumap code to convert
the xdp_frame into a xdp_buff and allow the ebpf program attached to the
map entry to differentiate traffic according to the receiving hw queue.
xdp_frame size is not increased adding queue_index since an alignment
padding in the structure is used to insert queue_index field.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
Changes since v1:
- rebase on top of bpf-next
---
 include/net/xdp.h   | 2 ++
 kernel/bpf/cpumap.c | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/net/xdp.h b/include/net/xdp.h
index 04c852c7a77f..3567866b0af5 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h
@@ -172,6 +172,7 @@ struct xdp_frame {
 	struct xdp_mem_info mem;
 	struct net_device *dev_rx; /* used by cpumap */
 	u32 flags; /* supported values defined in xdp_buff_flags */
+	u32 queue_index;
 };
 
 static __always_inline bool xdp_frame_has_frags(struct xdp_frame *frame)
@@ -301,6 +302,7 @@ struct xdp_frame *xdp_convert_buff_to_frame(struct xdp_buff *xdp)
 
 	/* rxq only valid until napi_schedule ends, convert to xdp_mem_info */
 	xdp_frame->mem = xdp->rxq->mem;
+	xdp_frame->queue_index = xdp->rxq->queue_index;
 
 	return xdp_frame;
 }
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index b5ba34ddd4b6..48003450c98c 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -228,7 +228,7 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu,
 
 		rxq.dev = xdpf->dev_rx;
 		rxq.mem = xdpf->mem;
-		/* TODO: report queue_index to xdp_rxq_info */
+		rxq.queue_index = xdpf->queue_index;
 
 		xdp_convert_frame_to_buff(xdpf, &xdp);
 
-- 
2.37.2