net/af_xdp: enable zero copy by external mbuf

Implement zero copy of af_xdp pmd through mbuf's external memory
mechanism to achieve high performance.

This patch also provides a new parameter "pmd_zero_copy" for user, so they
can choose to enable zero copy of af_xdp pmd or not.

To be clear, "zero copy" here is different from the "zero copy mode" of
AF_XDP, it is about zero copy between af_xdp umem and mbuf used in dpdk
application.

Suggested-by: Vipin Varghese <vipin.varghese@intel.com>
Suggested-by: Tummala Sivaprasad <sivaprasad.tummala@intel.com>
Suggested-by: Olivier Matz <olivier.matz@6wind.com>
Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
This commit is contained in:
Xiaolong Ye 2019-05-30 17:07:05 +08:00 committed by Ferruh Yigit
parent 4586be3743
commit e9ff8bb719
3 changed files with 86 additions and 26 deletions

View File

@ -28,6 +28,7 @@ The following options can be provided to set up an af_xdp port in DPDK.
* ``iface`` - name of the Kernel interface to attach to (required);
* ``queue`` - netdev queue id (optional, default 0);
* ``pmd_zero_copy`` - enable zero copy or not (optional, default 0);
Prerequisites
-------------

View File

@ -73,6 +73,13 @@ New Features
Added the new Shared Memory Packet Interface (``memif``) PMD.
See the :doc:`../nics/memif` guide for more details on this new driver.
* **Updated the AF_XDP PMD.**
Updated the AF_XDP PMD. The new features include:
* Enabled zero copy through mbuf's external memory mechanism to achieve
high performance
Removed Items
-------------

View File

@ -70,6 +70,7 @@ struct xsk_umem_info {
struct xsk_umem *umem;
struct rte_ring *buf_ring;
const struct rte_memzone *mz;
int pmd_zc;
};
struct rx_stats {
@ -109,8 +110,8 @@ struct pmd_internals {
int if_index;
char if_name[IFNAMSIZ];
uint16_t queue_idx;
int pmd_zc;
struct rte_ether_addr eth_addr;
struct xsk_umem_info *umem;
struct rte_mempool *mb_pool_share;
struct pkt_rx_queue rx_queues[ETH_AF_XDP_MAX_QUEUE_PAIRS];
@ -119,10 +120,12 @@ struct pmd_internals {
#define ETH_AF_XDP_IFACE_ARG "iface"
#define ETH_AF_XDP_QUEUE_IDX_ARG "queue"
#define ETH_AF_XDP_PMD_ZC_ARG "pmd_zero_copy"
static const char * const valid_arguments[] = {
ETH_AF_XDP_IFACE_ARG,
ETH_AF_XDP_QUEUE_IDX_ARG,
ETH_AF_XDP_PMD_ZC_ARG,
NULL
};
@ -166,6 +169,15 @@ reserve_fill_queue(struct xsk_umem_info *umem, uint16_t reserve_size)
return 0;
}
static void
umem_buf_release_to_fq(void *addr, void *opaque)
{
struct xsk_umem_info *umem = (struct xsk_umem_info *)opaque;
uint64_t umem_addr = (uint64_t)addr - umem->mz->addr_64;
rte_ring_enqueue(umem->buf_ring, (void *)umem_addr);
}
static uint16_t
eth_af_xdp_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
{
@ -175,6 +187,7 @@ eth_af_xdp_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
struct xsk_ring_prod *fq = &umem->fq;
uint32_t idx_rx = 0;
uint32_t free_thresh = fq->size >> 1;
int pmd_zc = umem->pmd_zc;
struct rte_mbuf *mbufs[ETH_AF_XDP_RX_BATCH_SIZE];
unsigned long dropped = 0;
unsigned long rx_bytes = 0;
@ -197,19 +210,29 @@ eth_af_xdp_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
uint64_t addr;
uint32_t len;
void *pkt;
uint16_t buf_len = ETH_AF_XDP_FRAME_SIZE;
struct rte_mbuf_ext_shared_info *shinfo;
desc = xsk_ring_cons__rx_desc(rx, idx_rx++);
addr = desc->addr;
len = desc->len;
pkt = xsk_umem__get_data(rxq->umem->mz->addr, addr);
rte_memcpy(rte_pktmbuf_mtod(mbufs[i], void *), pkt, len);
if (pmd_zc) {
shinfo = rte_pktmbuf_ext_shinfo_init_helper(pkt,
&buf_len, umem_buf_release_to_fq, umem);
rte_pktmbuf_attach_extbuf(mbufs[i], pkt, 0, buf_len,
shinfo);
} else {
rte_memcpy(rte_pktmbuf_mtod(mbufs[i], void *),
pkt, len);
rte_ring_enqueue(umem->buf_ring, (void *)addr);
}
rte_pktmbuf_pkt_len(mbufs[i]) = len;
rte_pktmbuf_data_len(mbufs[i]) = len;
rx_bytes += len;
bufs[i] = mbufs[i];
rte_ring_enqueue(umem->buf_ring, (void *)addr);
}
xsk_ring_cons__release(rx, rcvd);
@ -262,12 +285,21 @@ kick_tx(struct pkt_tx_queue *txq)
pull_umem_cq(umem, ETH_AF_XDP_TX_BATCH_SIZE);
}
static inline bool
in_umem_range(struct xsk_umem_info *umem, uint64_t addr)
{
uint64_t mz_base_addr = umem->mz->addr_64;
return addr >= mz_base_addr && addr < mz_base_addr + umem->mz->len;
}
static uint16_t
eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
{
struct pkt_tx_queue *txq = queue;
struct xsk_umem_info *umem = txq->pair->umem;
struct rte_mbuf *mbuf;
int pmd_zc = umem->pmd_zc;
void *addrs[ETH_AF_XDP_TX_BATCH_SIZE];
unsigned long tx_bytes = 0;
int i;
@ -294,16 +326,26 @@ eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
desc = xsk_ring_prod__tx_desc(&txq->tx, idx_tx + i);
mbuf = bufs[i];
desc->addr = (uint64_t)addrs[i];
desc->len = mbuf->pkt_len;
pkt = xsk_umem__get_data(umem->mz->addr,
desc->addr);
rte_memcpy(pkt, rte_pktmbuf_mtod(mbuf, void *),
desc->len);
tx_bytes += mbuf->pkt_len;
rte_pktmbuf_free(mbuf);
/*
* We need to make sure the external mbuf address is within
* current port's umem memzone range
*/
if (pmd_zc && RTE_MBUF_HAS_EXTBUF(mbuf) &&
in_umem_range(umem, (uint64_t)mbuf->buf_addr)) {
desc->addr = (uint64_t)mbuf->buf_addr -
umem->mz->addr_64;
mbuf->buf_addr = xsk_umem__get_data(umem->mz->addr,
(uint64_t)addrs[i]);
} else {
desc->addr = (uint64_t)addrs[i];
pkt = xsk_umem__get_data(umem->mz->addr,
desc->addr);
rte_memcpy(pkt, rte_pktmbuf_mtod(mbuf, void *),
desc->len);
}
tx_bytes += mbuf->pkt_len;
}
xsk_ring_prod__submit(&txq->tx, nb_pkts);
@ -313,6 +355,9 @@ eth_af_xdp_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
txq->stats.tx_pkts += nb_pkts;
txq->stats.tx_bytes += tx_bytes;
for (i = 0; i < nb_pkts; i++)
rte_pktmbuf_free(bufs[i]);
return nb_pkts;
}
@ -454,18 +499,16 @@ eth_dev_close(struct rte_eth_dev *dev)
if (rxq->umem == NULL)
break;
xsk_socket__delete(rxq->xsk);
(void)xsk_umem__delete(rxq->umem->umem);
xdp_umem_destroy(rxq->umem);
}
(void)xsk_umem__delete(internals->umem->umem);
/*
* MAC is not allocated dynamically, setting it to NULL would prevent
* from releasing it in rte_eth_dev_release_port.
*/
dev->data->mac_addrs = NULL;
xdp_umem_destroy(internals->umem);
remove_xdp_program(internals);
}
@ -639,7 +682,7 @@ eth_rx_queue_setup(struct rte_eth_dev *dev,
goto err;
}
internals->umem = rxq->umem;
rxq->umem->pmd_zc = internals->pmd_zc;
dev->data->rx_queues[rx_queue_id] = rxq;
return 0;
@ -775,9 +818,8 @@ parse_name_arg(const char *key __rte_unused,
}
static int
parse_parameters(struct rte_kvargs *kvlist,
char *if_name,
int *queue_idx)
parse_parameters(struct rte_kvargs *kvlist, char *if_name, int *queue_idx,
int *pmd_zc)
{
int ret;
@ -791,6 +833,11 @@ parse_parameters(struct rte_kvargs *kvlist,
if (ret < 0)
goto free_kvlist;
ret = rte_kvargs_process(kvlist, ETH_AF_XDP_PMD_ZC_ARG,
&parse_integer_arg, pmd_zc);
if (ret < 0)
goto free_kvlist;
free_kvlist:
rte_kvargs_free(kvlist);
return ret;
@ -827,9 +874,8 @@ get_iface_info(const char *if_name,
}
static struct rte_eth_dev *
init_internals(struct rte_vdev_device *dev,
const char *if_name,
int queue_idx)
init_internals(struct rte_vdev_device *dev, const char *if_name, int queue_idx,
int pmd_zc)
{
const char *name = rte_vdev_device_name(dev);
const unsigned int numa_node = dev->device.numa_node;
@ -843,6 +889,7 @@ init_internals(struct rte_vdev_device *dev,
return NULL;
internals->queue_idx = queue_idx;
internals->pmd_zc = pmd_zc;
strlcpy(internals->if_name, if_name, IFNAMSIZ);
for (i = 0; i < ETH_AF_XDP_MAX_QUEUE_PAIRS; i++) {
@ -868,6 +915,9 @@ init_internals(struct rte_vdev_device *dev,
/* Let rte_eth_dev_close() release the port resources. */
eth_dev->data->dev_flags |= RTE_ETH_DEV_CLOSE_REMOVE;
if (internals->pmd_zc)
AF_XDP_LOG(INFO, "Zero copy between umem and mbuf enabled.\n");
return eth_dev;
err:
@ -883,6 +933,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
int xsk_queue_idx = ETH_AF_XDP_DFLT_QUEUE_IDX;
struct rte_eth_dev *eth_dev = NULL;
const char *name;
int pmd_zc = 0;
AF_XDP_LOG(INFO, "Initializing pmd_af_xdp for %s\n",
rte_vdev_device_name(dev));
@ -909,7 +960,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
if (dev->device.numa_node == SOCKET_ID_ANY)
dev->device.numa_node = rte_socket_id();
if (parse_parameters(kvlist, if_name, &xsk_queue_idx) < 0) {
if (parse_parameters(kvlist, if_name, &xsk_queue_idx, &pmd_zc) < 0) {
AF_XDP_LOG(ERR, "Invalid kvargs value\n");
return -EINVAL;
}
@ -919,7 +970,7 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
return -EINVAL;
}
eth_dev = init_internals(dev, if_name, xsk_queue_idx);
eth_dev = init_internals(dev, if_name, xsk_queue_idx, pmd_zc);
if (eth_dev == NULL) {
AF_XDP_LOG(ERR, "Failed to init internals\n");
return -1;
@ -961,7 +1012,8 @@ static struct rte_vdev_driver pmd_af_xdp_drv = {
RTE_PMD_REGISTER_VDEV(net_af_xdp, pmd_af_xdp_drv);
RTE_PMD_REGISTER_PARAM_STRING(net_af_xdp,
"iface=<string> "
"queue=<int> ");
"queue=<int> "
"pmd_zero_copy=<0|1>");
RTE_INIT(af_xdp_init_log)
{