> > On 2/4/2022 12:54 PM, Ciara Loftus wrote: > > Secondary process support had been disabled for the AF_XDP PMD > > because there was no logic in place to share the AF_XDP socket > > file descriptors between the processes. This commit introduces > > this logic using the IPC APIs. > > > > Since AF_XDP rings are single-producer single-consumer, rx/tx > > in the secondary process is disabled. However other operations > > including retrieval of stats are permitted. > > > > Signed-off-by: Ciara Loftus <ciara.lof...@intel.com> > > > > --- > > v1 -> v2: > > * Rebase to next-net > > > > RFC -> v1: > > * Added newline to af_xdp.rst > > * Fixed spelling errors > > * Fixed potential NULL dereference in init_internals > > * Fixed potential free of address-of expression in afxdp_mp_request_fds > > --- > > doc/guides/nics/af_xdp.rst | 9 ++ > > doc/guides/nics/features/af_xdp.ini | 1 + > > doc/guides/rel_notes/release_22_03.rst | 1 + > > drivers/net/af_xdp/rte_eth_af_xdp.c | 210 > +++++++++++++++++++++++-- > > 4 files changed, 207 insertions(+), 14 deletions(-) > > > > diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst > > index db02ea1984..eb4eab28a8 100644 > > --- a/doc/guides/nics/af_xdp.rst > > +++ b/doc/guides/nics/af_xdp.rst > > @@ -141,4 +141,13 @@ Limitations > > NAPI context from a watchdog timer instead of from softirqs. More > information > > on this feature can be found at [1]. > > > > +- **Secondary Processes** > > + > > + Rx and Tx are not supported for secondary processes due to the single- > producer > > + single-consumer nature of the AF_XDP rings. However other operations > including > > + statistics retrieval are permitted. > > Hi Ciara, > > Isn't this limitation same for all PMDs, like not both primary & secondary can > Rx/Tx > from same queue at the same time. > But primary can initiallize the PMD and secondary can do the datapath, > or isn't af_xdp supports multiple queue, if so some queues can be used by > primary and some by secondary for datapath. > > Is there anyhing special for af_xdp that prevents it?
Hi Ferruh, Thanks for the review. Each queue of the PMD corresponds to a new AF_XDP socket. Each socket has an RX and TX ring that is mmapped from the kernel to userspace and this mapping is only valid for the primary process. I did not figure out a way to share that mapping with the secondary process successfully. Can you think of anything that might work? > > > + The maximum number of queues permitted for PMDs operating in this > model is 8 > > + as this is the maximum number of fds that can be sent through the IPC > APIs as > > + defined by RTE_MP_MAX_FD_NUM. > > + > > [1] https://lwn.net/Articles/837010/ > > diff --git a/doc/guides/nics/features/af_xdp.ini > b/doc/guides/nics/features/af_xdp.ini > > index 54b738e616..8e7e075aaf 100644 > > --- a/doc/guides/nics/features/af_xdp.ini > > +++ b/doc/guides/nics/features/af_xdp.ini > > @@ -9,4 +9,5 @@ Power mgmt address monitor = Y > > MTU update = Y > > Promiscuous mode = Y > > Stats per queue = Y > > +Multiprocess aware = Y > > x86-64 = Y > > diff --git a/doc/guides/rel_notes/release_22_03.rst > b/doc/guides/rel_notes/release_22_03.rst > > index bf2e3f78a9..dfd2cbbccf 100644 > > --- a/doc/guides/rel_notes/release_22_03.rst > > +++ b/doc/guides/rel_notes/release_22_03.rst > > @@ -58,6 +58,7 @@ New Features > > * **Updated AF_XDP PMD** > > > > * Added support for libxdp >=v1.2.2. > > + * Re-enabled secondary process support. RX/TX is not supported. > > > > * **Updated Cisco enic driver.** > > > > diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c > b/drivers/net/af_xdp/rte_eth_af_xdp.c > > index 1b6192fa44..407f6d8dbe 100644 > > --- a/drivers/net/af_xdp/rte_eth_af_xdp.c > > +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c > > @@ -80,6 +80,18 @@ RTE_LOG_REGISTER_DEFAULT(af_xdp_logtype, > NOTICE); > > > > #define ETH_AF_XDP_ETH_OVERHEAD > (RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN) > > > > +#define ETH_AF_XDP_MP_KEY "afxdp_mp_send_fds" > > + > > +static int afxdp_dev_count; > > + > > +/* Message header to synchronize fds via IPC */ > > +struct ipc_hdr { > > + char port_name[RTE_DEV_NAME_MAX_LEN]; > > + /* The file descriptors are in the dedicated part > > + * of the Unix message to be translated by the kernel. > > + */ > > +}; > > + > > struct xsk_umem_info { > > struct xsk_umem *umem; > > struct rte_ring *buf_ring; > > @@ -147,6 +159,10 @@ struct pmd_internals { > > struct pkt_tx_queue *tx_queues; > > }; > > > > +struct pmd_process_private { > > + int rxq_xsk_fds[RTE_MAX_QUEUES_PER_PORT]; > > +}; > > + > > #define ETH_AF_XDP_IFACE_ARG "iface" > > #define ETH_AF_XDP_START_QUEUE_ARG "start_queue" > > #define ETH_AF_XDP_QUEUE_COUNT_ARG > "queue_count" > > @@ -795,11 +811,12 @@ static int > > eth_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats *stats) > > { > > struct pmd_internals *internals = dev->data->dev_private; > > + struct pmd_process_private *process_private = dev- > >process_private; > > struct xdp_statistics xdp_stats; > > struct pkt_rx_queue *rxq; > > struct pkt_tx_queue *txq; > > socklen_t optlen; > > - int i, ret; > > + int i, ret, fd; > > > > for (i = 0; i < dev->data->nb_rx_queues; i++) { > > optlen = sizeof(struct xdp_statistics); > > @@ -815,8 +832,9 @@ eth_stats_get(struct rte_eth_dev *dev, struct > rte_eth_stats *stats) > > stats->ibytes += stats->q_ibytes[i]; > > stats->imissed += rxq->stats.rx_dropped; > > stats->oerrors += txq->stats.tx_dropped; > > - ret = getsockopt(xsk_socket__fd(rxq->xsk), SOL_XDP, > > - XDP_STATISTICS, &xdp_stats, &optlen); > > + fd = process_private->rxq_xsk_fds[i]; > > + ret = fd >= 0 ? getsockopt(fd, SOL_XDP, XDP_STATISTICS, > > + &xdp_stats, &optlen) : -1; > > if (ret != 0) { > > AF_XDP_LOG(ERR, "getsockopt() failed for > XDP_STATISTICS.\n"); > > return -1; > > @@ -883,8 +901,10 @@ eth_dev_close(struct rte_eth_dev *dev) > > struct pkt_rx_queue *rxq; > > int i; > > > > - if (rte_eal_process_type() != RTE_PROC_PRIMARY) > > + if (rte_eal_process_type() != RTE_PROC_PRIMARY) { > > + rte_free(dev->process_private); > > return 0; > > + } > > > > AF_XDP_LOG(INFO, "Closing AF_XDP ethdev on numa socket %u\n", > > rte_socket_id()); > > @@ -1349,6 +1369,7 @@ eth_rx_queue_setup(struct rte_eth_dev *dev, > > struct rte_mempool *mb_pool) > > { > > struct pmd_internals *internals = dev->data->dev_private; > > + struct pmd_process_private *process_private = dev- > >process_private; > > struct pkt_rx_queue *rxq; > > int ret; > > > > @@ -1387,6 +1408,8 @@ eth_rx_queue_setup(struct rte_eth_dev *dev, > > rxq->fds[0].fd = xsk_socket__fd(rxq->xsk); > > rxq->fds[0].events = POLLIN; > > > > + process_private->rxq_xsk_fds[rx_queue_id] = rxq->fds[0].fd; > > + > > dev->data->rx_queues[rx_queue_id] = rxq; > > return 0; > > > > @@ -1688,6 +1711,7 @@ init_internals(struct rte_vdev_device *dev, const > char *if_name, > > { > > const char *name = rte_vdev_device_name(dev); > > const unsigned int numa_node = dev->device.numa_node; > > + struct pmd_process_private *process_private; > > struct pmd_internals *internals; > > struct rte_eth_dev *eth_dev; > > int ret; > > @@ -1753,9 +1777,17 @@ init_internals(struct rte_vdev_device *dev, > const char *if_name, > > if (ret) > > goto err_free_tx; > > > > + process_private = (struct pmd_process_private *) > > + rte_zmalloc_socket(name, sizeof(struct > pmd_process_private), > > + RTE_CACHE_LINE_SIZE, numa_node); > > + if (process_private == NULL) { > > + AF_XDP_LOG(ERR, "Failed to alloc memory for process > private\n"); > > + goto err_free_tx; > > + } > > Need to free 'process_private' in the PMD, in 'close()' and 'remove()' paths. +1 > > > + > > eth_dev = rte_eth_vdev_allocate(dev, 0); > > if (eth_dev == NULL) > > - goto err_free_tx; > > + goto err_free_pp; > > > > eth_dev->data->dev_private = internals; > > eth_dev->data->dev_link = pmd_link; > > @@ -1764,6 +1796,10 @@ init_internals(struct rte_vdev_device *dev, > const char *if_name, > > eth_dev->dev_ops = &ops; > > eth_dev->rx_pkt_burst = eth_af_xdp_rx; > > eth_dev->tx_pkt_burst = eth_af_xdp_tx; > > + eth_dev->process_private = process_private; > > + > > + for (i = 0; i < queue_cnt; i++) > > + process_private->rxq_xsk_fds[i] = -1; > > > > #if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG) > > AF_XDP_LOG(INFO, "Zero copy between umem and mbuf > enabled.\n"); > > @@ -1771,6 +1807,8 @@ init_internals(struct rte_vdev_device *dev, const > char *if_name, > > > > return eth_dev; > > > > +err_free_pp: > > + rte_free(process_private); > > err_free_tx: > > rte_free(internals->tx_queues); > > err_free_rx: > > @@ -1780,6 +1818,115 @@ init_internals(struct rte_vdev_device *dev, > const char *if_name, > > return NULL; > > } > > > > +/* Secondary process requests rxq fds from primary. */ > > +static int > > +afxdp_mp_request_fds(const char *name, struct rte_eth_dev *dev) > > +{ > > + struct pmd_process_private *process_private = dev- > >process_private; > > + struct timespec timeout = {.tv_sec = 1, .tv_nsec = 0}; > > + struct rte_mp_msg request, *reply; > > + struct rte_mp_reply replies; > > + struct ipc_hdr *request_param = (struct ipc_hdr *)request.param; > > + int i, ret; > > + > > + /* Prepare the request */ > > + memset(&request, 0, sizeof(request)); > > + strlcpy(request.name, ETH_AF_XDP_MP_KEY, > sizeof(request.name)); > > + strlcpy(request_param->port_name, name, > > + sizeof(request_param->port_name)); > > + request.len_param = sizeof(*request_param); > > + > > + /* Send the request and receive the reply */ > > + AF_XDP_LOG(DEBUG, "Sending IPC request for %s\n", name); > > + ret = rte_mp_request_sync(&request, &replies, &timeout); > > + if (ret < 0 || replies.nb_received != 1) { > > + AF_XDP_LOG(ERR, "Failed to request fds from primary: %d", > > + rte_errno); > > + return -1; > > + } > > + reply = replies.msgs; > > + AF_XDP_LOG(DEBUG, "Received IPC reply for %s\n", name); > > I think message can mention "multi-process IPC" for clarification. +1 > > > + if (dev->data->nb_rx_queues != reply->num_fds) { > > + AF_XDP_LOG(ERR, "Incorrect number of fds received: %d != > %d\n", > > + reply->num_fds, dev->data->nb_rx_queues); > > + return -EINVAL; > > + } > > + > > + for (i = 0; i < reply->num_fds; i++) > > + process_private->rxq_xsk_fds[i] = reply->fds[i]; > > + > > + free(reply); > > + return 0; > > +} > > + > > +/* Primary process sends rxq fds to secondary. */ > > +static int > > +afxdp_mp_send_fds(const struct rte_mp_msg *request, const void > *peer) > > +{ > > + struct rte_eth_dev *dev; > > + struct pmd_process_private *process_private; > > + struct rte_mp_msg reply; > > + const struct ipc_hdr *request_param = > > + (const struct ipc_hdr *)request->param; > > + struct ipc_hdr *reply_param = > > + (struct ipc_hdr *)reply.param; > > + const char *request_name = request_param->port_name; > > + uint16_t port_id; > > + int i, ret; > > + > > + AF_XDP_LOG(DEBUG, "Received IPC request for %s\n", > request_name); > > + > > + /* Find the requested port */ > > + ret = rte_eth_dev_get_port_by_name(request_name, &port_id); > > + if (ret) { > > + AF_XDP_LOG(ERR, "Failed to get port id for %s\n", > request_name); > > + return -1; > > + } > > + dev = &rte_eth_devices[port_id]; > > Better to not access the global array, there is a new API and a cleanup > already done [1] in other PMDs, can you please apply the same here. > > [1] > https://patches.dpdk.org/project/dpdk/patch/20220203082412.79028-1- > kumaraparames...@gmail.com/ Thanks for sharing, I wasn't aware of this API. I'll add it in the v3. > > > + process_private = dev->process_private; > > + > > + /* Populate the reply with the xsk fd for each queue */ > > + reply.num_fds = 0; > > + if (dev->data->nb_rx_queues > RTE_MP_MAX_FD_NUM) { > > + AF_XDP_LOG(ERR, "Number of rx queues (%d) exceeds max > number of fds (%d)\n", > > + dev->data->nb_rx_queues, > RTE_MP_MAX_FD_NUM); > > + return -EINVAL; > > + } > > + > > + for (i = 0; i < dev->data->nb_rx_queues; i++) > > + reply.fds[reply.num_fds++] = process_private- > >rxq_xsk_fds[i]; > > + > > + /* Send the reply */ > > + strlcpy(reply.name, request->name, sizeof(reply.name)); > > + strlcpy(reply_param->port_name, request_name, > > + sizeof(reply_param->port_name)); > > + reply.len_param = sizeof(*reply_param); > > + AF_XDP_LOG(DEBUG, "Sending IPC reply for %s\n", reply_param- > >port_name); > > + if (rte_mp_reply(&reply, peer) < 0) { > > + AF_XDP_LOG(ERR, "Failed to reply to IPC request\n"); > > + return -1; > > + } > > + return 0; > > +} > > + > > +/* Secondary process rx function. RX is disabled because rings are SPSC */ > > +static uint16_t > > +eth_af_xdp_rx_noop(void *queue __rte_unused, > > + struct rte_mbuf **bufs __rte_unused, > > + uint16_t nb_pkts __rte_unused) > > +{ > > + return 0; > > +} > > + > > +/* Secondary process tx function. TX is disabled because rings are SPSC */ > > +static uint16_t > > +eth_af_xdp_tx_noop(void *queue __rte_unused, > > + struct rte_mbuf **bufs __rte_unused, > > + uint16_t nb_pkts __rte_unused) > > +{ > > + return 0; > > +} > > + > > Now there are multiple PMDs using noop/dummy Rx/Tx burst functions, > what do you think to add static inline functions in the 'ethdev_driver.h' > (and clean existing drivers to use it) with a separate patch, later in this > patch use those functions? +1 > > > > static int > > rte_pmd_af_xdp_probe(struct rte_vdev_device *dev) > > { > > @@ -1789,19 +1936,39 @@ rte_pmd_af_xdp_probe(struct > rte_vdev_device *dev) > > int xsk_queue_cnt = ETH_AF_XDP_DFLT_QUEUE_COUNT; > > int shared_umem = 0; > > char prog_path[PATH_MAX] = {'\0'}; > > - int busy_budget = -1; > > + int busy_budget = -1, ret; > > struct rte_eth_dev *eth_dev = NULL; > > - const char *name; > > + const char *name = rte_vdev_device_name(dev); > > > > - AF_XDP_LOG(INFO, "Initializing pmd_af_xdp for %s\n", > > - rte_vdev_device_name(dev)); > > + AF_XDP_LOG(INFO, "Initializing pmd_af_xdp for %s\n", name); > > > > - name = rte_vdev_device_name(dev); > > if (rte_eal_process_type() == RTE_PROC_SECONDARY) { > > - AF_XDP_LOG(ERR, "Failed to probe %s. " > > - "AF_XDP PMD does not support secondary > processes.\n", > > - name); > > - return -ENOTSUP; > > + eth_dev = rte_eth_dev_attach_secondary(name); > > + if (eth_dev == NULL) { > > + AF_XDP_LOG(ERR, "Failed to probe %s\n", name); > > + return -EINVAL; > > + } > > + eth_dev->dev_ops = &ops; > > + eth_dev->device = &dev->device; > > + eth_dev->rx_pkt_burst = eth_af_xdp_rx_noop; > > + eth_dev->tx_pkt_burst = eth_af_xdp_tx_noop; > > + eth_dev->process_private = (struct pmd_process_private *) > > + rte_zmalloc_socket(name, > > + sizeof(struct > pmd_process_private), > > + RTE_CACHE_LINE_SIZE, > > + eth_dev->device->numa_node); > > + if (eth_dev->process_private == NULL) { > > + AF_XDP_LOG(ERR, > > + "Failed to alloc memory for process > private\n"); > > + return -ENOMEM; > > + } > > + > > + /* Obtain the xsk fds from the primary process. */ > > + if (afxdp_mp_request_fds(name, eth_dev)) > > + return -1; > > + > > + rte_eth_dev_probing_finish(eth_dev); > > + return 0; > > } > > > > kvlist = rte_kvargs_parse(rte_vdev_device_args(dev), > valid_arguments); > > @@ -1836,6 +2003,17 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device > *dev) > > return -1; > > } > > > > + /* Register IPC callback which shares xsk fds from primary to > secondary */ > > + if (!afxdp_dev_count) { > > + ret = rte_mp_action_register(ETH_AF_XDP_MP_KEY, > afxdp_mp_send_fds); > > + if (ret < 0) { > > + AF_XDP_LOG(ERR, "%s: Failed to register IPC > callback: %s", > > + name, strerror(rte_errno)); > > + return -1; > > + } > > + } > > + afxdp_dev_count++; > > + > > rte_eth_dev_probing_finish(eth_dev); > > > > return 0; > > @@ -1858,6 +2036,10 @@ rte_pmd_af_xdp_remove(struct > rte_vdev_device *dev) > > return 0; > > > > eth_dev_close(eth_dev); > > + rte_free(eth_dev->process_private); > > + if (afxdp_dev_count == 1) > > + rte_mp_action_unregister(ETH_AF_XDP_MP_KEY); > > + afxdp_dev_count--; > > rte_eth_dev_release_port(eth_dev); > > > >
