[dpdk-dev] [PATCH 2/3] net/af_xdp: use correct fill queue addresses

[Ciara Loftus]

The fill queue addresses should start at the beginning of the mempool
object instead of the beginning of the mbuf. This is because the umem frame
headroom includes the mp hdrobj size. Starting at this point ensures AF_XDP
doesn't write past the available room in the frame, in the case of larger
packets which are close to the size of the mbuf.

Fixes: d8a210774e1d ("net/af_xdp: support unaligned umem chunks")
Cc: stable at dpdk.org

Signed-off-by: Ciara Loftus <ciara.loftus at intel.com>
---
 drivers/net/af_xdp/rte_eth_af_xdp.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
index 8b189119c..ebc64d4dd 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -172,7 +172,8 @@ reserve_fill_queue_zc(struct xsk_umem_info *umem, uint16_t reserve_size,
 		uint64_t addr;
 
 		fq_addr = xsk_ring_prod__fill_addr(fq, idx++);
-		addr = (uint64_t)bufs[i] - (uint64_t)umem->buffer;
+		addr = (uint64_t)bufs[i] - (uint64_t)umem->buffer -
+				umem->mb_pool->header_size;
 		*fq_addr = addr;
 	}
 
@@ -271,8 +272,10 @@ af_xdp_rx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 		addr = xsk_umem__extract_addr(addr);
 
 		bufs[i] = (struct rte_mbuf *)
-				xsk_umem__get_data(umem->buffer, addr);
-		bufs[i]->data_off = offset - sizeof(struct rte_mbuf);
+				xsk_umem__get_data(umem->buffer, addr +
+					umem->mb_pool->header_size);
+		bufs[i]->data_off = offset - sizeof(struct rte_mbuf) -
+			umem->mb_pool->header_size;
 
 		rte_pktmbuf_pkt_len(bufs[i]) = len;
 		rte_pktmbuf_data_len(bufs[i]) = len;
@@ -385,7 +388,8 @@ pull_umem_cq(struct xsk_umem_info *umem, int size)
 #if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
 		addr = xsk_umem__extract_addr(addr);
 		rte_pktmbuf_free((struct rte_mbuf *)
-					xsk_umem__get_data(umem->buffer, addr));
+					xsk_umem__get_data(umem->buffer,
+					addr + umem->mb_pool->header_size));
 #else
 		rte_ring_enqueue(umem->buf_ring, (void *)addr);
 #endif
@@ -443,9 +447,11 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 			}
 			desc = xsk_ring_prod__tx_desc(&txq->tx, idx_tx);
 			desc->len = mbuf->pkt_len;
-			addr = (uint64_t)mbuf - (uint64_t)umem->buffer;
+			addr = (uint64_t)mbuf - (uint64_t)umem->buffer -
+					umem->mb_pool->header_size;
 			offset = rte_pktmbuf_mtod(mbuf, uint64_t) -
-					(uint64_t)mbuf;
+					(uint64_t)mbuf +
+					umem->mb_pool->header_size;
 			offset = offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT;
 			desc->addr = addr | offset;
 			count++;
@@ -466,9 +472,11 @@ af_xdp_tx_zc(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 			desc = xsk_ring_prod__tx_desc(&txq->tx, idx_tx);
 			desc->len = mbuf->pkt_len;
 
-			addr = (uint64_t)local_mbuf - (uint64_t)umem->buffer;
+			addr = (uint64_t)local_mbuf - (uint64_t)umem->buffer -
+					umem->mb_pool->header_size;
 			offset = rte_pktmbuf_mtod(local_mbuf, uint64_t) -
-					(uint64_t)local_mbuf;
+					(uint64_t)local_mbuf +
+					umem->mb_pool->header_size;
 			pkt = xsk_umem__get_data(umem->buffer, addr + offset);
 			offset = offset << XSK_UNALIGNED_BUF_OFFSET_SHIFT;
 			desc->addr = addr | offset;
-- 
2.17.1