[v3,2/3] net/af_xdp: use correct fill queue addresses

  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@dpdk.org

Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
---
 drivers/net/af_xdp/rte_eth_af_xdp.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)
  

On 02/10, Ciara Loftus wrote:
>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@dpdk.org
>
>Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
>---
> 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
>

Reviewed-by: Xiaolong Ye <xiaolong.ye@intel.com>