[dpdk-stable] [PATCH v2 3/3] net/af_xdp: fix maximum MTU value
Ciara Loftus
ciara.loftus at intel.com
Fri Feb 7 18:03:28 CET 2020
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: stable at dpdk.org
Signed-off-by: Ciara Loftus <ciara.loftus at 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 1e98cd44f..75f037c3e 100644
--- a/drivers/net/af_xdp/rte_eth_af_xdp.c
+++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
@@ -59,13 +59,6 @@ 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
@@ -602,7 +595,14 @@ 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;
+#endif
dev_info->default_rxportconf.nb_queues = 1;
dev_info->default_txportconf.nb_queues = 1;
@@ -804,7 +804,7 @@ 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;
@@ -829,8 +829,7 @@ 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);
@@ -939,7 +938,7 @@ 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
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