On 02/13, Ciara Loftus wrote:
>The maximum MTU for af_xdp zero copy is equal to the page size less the
>frame overhead introduced by AF_XDP (XDP HR = 256) and DPDK (frame headroom
>= 320). The patch updates this value to reflect this.
>
>This change also makes it possible to remove unneeded constants for both
>zero-copy and copy mode.
>
>Fixes: d8a210774e1d ("net/af_xdp: support unaligned umem chunks")
>Cc: sta...@dpdk.org
>
>Signed-off-by: Ciara Loftus <ciara.lof...@intel.com>
>---
> drivers/net/af_xdp/rte_eth_af_xdp.c | 23 +++++++++++------------
> 1 file changed, 11 insertions(+), 12 deletions(-)
>
>diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c
>b/drivers/net/af_xdp/rte_eth_af_xdp.c
>index a0edfc3cd3..06124ba789 100644
>--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
>+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
>@@ -58,13 +58,6 @@ static int af_xdp_logtype;
>
> #define ETH_AF_XDP_FRAME_SIZE 2048
> #define ETH_AF_XDP_NUM_BUFFERS 4096
>-#ifdef XDP_UMEM_UNALIGNED_CHUNK_FLAG
>-#define ETH_AF_XDP_MBUF_OVERHEAD 128 /* sizeof(struct rte_mbuf) */
>-#define ETH_AF_XDP_DATA_HEADROOM \
>- (ETH_AF_XDP_MBUF_OVERHEAD + RTE_PKTMBUF_HEADROOM)
>-#else
>-#define ETH_AF_XDP_DATA_HEADROOM 0
>-#endif
> #define ETH_AF_XDP_DFLT_NUM_DESCS XSK_RING_CONS__DEFAULT_NUM_DESCS
> #define ETH_AF_XDP_DFLT_START_QUEUE_IDX 0
> #define ETH_AF_XDP_DFLT_QUEUE_COUNT 1
>@@ -601,7 +594,14 @@ eth_dev_info(struct rte_eth_dev *dev, struct
>rte_eth_dev_info *dev_info)
> dev_info->max_tx_queues = internals->queue_cnt;
>
> dev_info->min_mtu = RTE_ETHER_MIN_MTU;
>- dev_info->max_mtu = ETH_AF_XDP_FRAME_SIZE - ETH_AF_XDP_DATA_HEADROOM;
>+#if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
>+ dev_info->max_mtu = getpagesize() -
>+ sizeof(struct rte_mempool_objhdr) -
>+ sizeof(struct rte_mbuf) -
>+ RTE_PKTMBUF_HEADROOM - XDP_PACKET_HEADROOM;
>+#else
>+ dev_info->max_mtu = ETH_AF_XDP_FRAME_SIZE - XDP_PACKET_HEADROOM;
>+#endif
>
> dev_info->default_rxportconf.nb_queues = 1;
> dev_info->default_txportconf.nb_queues = 1;
>@@ -803,7 +803,7 @@ xsk_umem_info *xdp_umem_configure(struct pmd_internals
>*internals,
> .fill_size = ETH_AF_XDP_DFLT_NUM_DESCS,
> .comp_size = ETH_AF_XDP_DFLT_NUM_DESCS,
> .frame_size = ETH_AF_XDP_FRAME_SIZE,
>- .frame_headroom = ETH_AF_XDP_DATA_HEADROOM };
>+ .frame_headroom = 0 };
> char ring_name[RTE_RING_NAMESIZE];
> char mz_name[RTE_MEMZONE_NAMESIZE];
> int ret;
>@@ -828,8 +828,7 @@ xsk_umem_info *xdp_umem_configure(struct pmd_internals
>*internals,
>
> for (i = 0; i < ETH_AF_XDP_NUM_BUFFERS; i++)
> rte_ring_enqueue(umem->buf_ring,
>- (void *)(i * ETH_AF_XDP_FRAME_SIZE +
>- ETH_AF_XDP_DATA_HEADROOM));
>+ (void *)(i * ETH_AF_XDP_FRAME_SIZE));
>
> snprintf(mz_name, sizeof(mz_name), "af_xdp_umem_%s_%u",
> internals->if_name, rxq->xsk_queue_idx);
>@@ -938,7 +937,7 @@ eth_rx_queue_setup(struct rte_eth_dev *dev,
> /* Now get the space available for data in the mbuf */
> buf_size = rte_pktmbuf_data_room_size(mb_pool) -
> RTE_PKTMBUF_HEADROOM;
>- data_size = ETH_AF_XDP_FRAME_SIZE - ETH_AF_XDP_DATA_HEADROOM;
>+ data_size = ETH_AF_XDP_FRAME_SIZE;
>
> if (data_size > buf_size) {
> AF_XDP_LOG(ERR, "%s: %d bytes will not fit in mbuf (%d
> bytes)\n",
>--
>2.17.1
>
Reviewed-by: Xiaolong Ye <xiaolong...@intel.com>
