[dpdk-dev] [PATCH v2 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>
---
v2:
* Include mbuf priv size in rx mbuf data_off calculation

Ciara Loftus (3):
  net/af_xdp: fix umem frame size & headroom calculations
  net/af_xdp: use correct fill queue addresses
  net/af_xdp: fix maximum MTU value

 drivers/net/af_xdp/rte_eth_af_xdp.c | 60 +++++++++++++++++------------
 1 file changed, 35 insertions(+), 25 deletions(-)

-- 
2.17.1

 drivers/net/af_xdp/rte_eth_af_xdp.c | 25 +++++++++++++++++--------
 1 file changed, 17 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..1e98cd44f 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 +272,11 @@ 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) -
+			rte_pktmbuf_priv_size(umem->mb_pool) -
+			umem->mb_pool->header_size;
 
 		rte_pktmbuf_pkt_len(bufs[i]) = len;
 		rte_pktmbuf_data_len(bufs[i]) = len;
@@ -385,7 +389,8 @@ 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 +448,11 @@ 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 +473,11 @@ 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