RE: [Patch v6 01/18] net/mana: add basic driver, build environment and doc

[Long Li <longli@microsoft.com>]

> Subject: Re: [Patch v6 01/18] net/mana: add basic driver, build environment
> and doc
> 
> 
> 在 2022/9/1 2:05, Long Li 写道:
> >> Subject: Re: [Patch v6 01/18] net/mana: add basic driver, build
> >> environment and doc
> >>
> >>
> >> 在 2022/8/31 6:51, longli@linuxonhyperv.com 写道:
> >>> From: Long Li <longli@microsoft.com>
> >>>
> >>> MANA is a PCI device. It uses IB verbs to access hardware through
> >>> the kernel RDMA layer. This patch introduces build environment and
> >>> basic device probe functions.
> >>>
> >>> Signed-off-by: Long Li <longli@microsoft.com>
> >>> ---
> >>> Change log:
> >>> v2:
> >>> Fix typos.
> >>> Make the driver build only on x86-64 and Linux.
> >>> Remove unused header files.
> >>> Change port definition to uint16_t or uint8_t (for IB).
> >>> Use getline() in place of fgets() to read and truncate a line.
> >>> v3:
> >>> Add meson build check for required functions from RDMA direct verb
> >>> header file
> >>> v4:
> >>> Remove extra "\n" in logging code.
> >>> Use "r" in place of "rb" in fopen() to read text files.
> >>>
> >>> [snip]
> >>> +
> >>> +static int mana_pci_probe_mac(struct rte_pci_driver *pci_drv
> >> __rte_unused,
> >>> +			      struct rte_pci_device *pci_dev,
> >>> +			      struct rte_ether_addr *mac_addr) {
> >>> +	struct ibv_device **ibv_list;
> >>> +	int ibv_idx;
> >>> +	struct ibv_context *ctx;
> >>> +	struct ibv_device_attr_ex dev_attr;
> >>> +	int num_devices;
> >>> +	int ret = 0;
> >>> +	uint8_t port;
> >>> +	struct mana_priv *priv = NULL;
> >>> +	struct rte_eth_dev *eth_dev = NULL;
> >>> +	bool found_port;
> >>> +
> >>> +	ibv_list = ibv_get_device_list(&num_devices);
> >>> +	for (ibv_idx = 0; ibv_idx < num_devices; ibv_idx++) {
> >>> +		struct ibv_device *ibdev = ibv_list[ibv_idx];
> >>> +		struct rte_pci_addr pci_addr;
> >>> +
> >>> +		DRV_LOG(INFO, "Probe device name %s dev_name %s
> >> ibdev_path %s",
> >>> +			ibdev->name, ibdev->dev_name, ibdev-
> >>> ibdev_path);
> >>> +
> >>> +		if (mana_ibv_device_to_pci_addr(ibdev, &pci_addr))
> >>> +			continue;
> >>> +
> >>> +		/* Ignore if this IB device is not this PCI device */
> >>> +		if (pci_dev->addr.domain != pci_addr.domain ||
> >>> +		    pci_dev->addr.bus != pci_addr.bus ||
> >>> +		    pci_dev->addr.devid != pci_addr.devid ||
> >>> +		    pci_dev->addr.function != pci_addr.function)
> >>> +			continue;
> >>> +
> >>> +		ctx = ibv_open_device(ibdev);
> >>> +		if (!ctx) {
> >>> +			DRV_LOG(ERR, "Failed to open IB device %s",
> >>> +				ibdev->name);
> >>> +			continue;
> >>> +		}
> >>> +
> >>> +		ret = ibv_query_device_ex(ctx, NULL, &dev_attr);
> >>> +		DRV_LOG(INFO, "dev_attr.orig_attr.phys_port_cnt %u",
> >>> +			dev_attr.orig_attr.phys_port_cnt);
> >>> +		found_port = false;
> >>> +
> >>> +		for (port = 1; port <= dev_attr.orig_attr.phys_port_cnt;
> >>> +		     port++) {
> >>> +			struct ibv_parent_domain_init_attr attr = {};
> >>> +			struct rte_ether_addr addr;
> >>> +			char address[64];
> >>> +			char name[RTE_ETH_NAME_MAX_LEN];
> >>> +
> >>> +			ret = get_port_mac(ibdev, port, &addr);
> >>> +			if (ret)
> >>> +				continue;
> >>> +
> >>> +			if (mac_addr && !rte_is_same_ether_addr(&addr,
> >> mac_addr))
> >>> +				continue;
> >>> +
> >>> +			rte_ether_format_addr(address, sizeof(address),
> >> &addr);
> >>> +			DRV_LOG(INFO, "device located port %u address
> >> %s",
> >>> +				port, address);
> >>> +			found_port = true;
> >>> +
> >>> +			priv = rte_zmalloc_socket(NULL, sizeof(*priv),
> >>> +						  RTE_CACHE_LINE_SIZE,
> >>> +						  SOCKET_ID_ANY);
> >>> +			if (!priv) {
> >>> +				ret = -ENOMEM;
> >>> +				goto failed;
> >>> +			}
> >>> +
> >>> +			snprintf(name, sizeof(name), "%s_port%d",
> >>> +				 pci_dev->device.name, port);
> >>> +
> >>> +			if (rte_eal_process_type() ==
> >> RTE_PROC_SECONDARY) {
> >>> +				int fd;
> >>> +
> >>> +				eth_dev =
> >> rte_eth_dev_attach_secondary(name);
> >>> +				if (!eth_dev) {
> >>> +					DRV_LOG(ERR, "Can't attach to dev
> >> %s",
> >>> +						name);
> >>> +					ret = -ENOMEM;
> >>> +					goto failed;
> >>> +				}
> >>> +
> >>> +				eth_dev->device = &pci_dev->device;
> >>> +				eth_dev->dev_ops = &mana_dev_sec_ops;
> >>> +				ret = mana_proc_priv_init(eth_dev);
> >>> +				if (ret)
> >>> +					goto failed;
> >>> +				priv->process_priv = eth_dev-
> >>> process_private;
> >>> +
> >>> +				/* Get the IB FD from the primary process */
> >>> +				fd =
> >> mana_mp_req_verbs_cmd_fd(eth_dev);
> >>> +				if (fd < 0) {
> >>> +					DRV_LOG(ERR, "Failed to get FD %d",
> >> fd);
> >>> +					ret = -ENODEV;
> >>> +					goto failed;
> >>> +				}
> >>> +
> >>> +				ret =
> >> mana_map_doorbell_secondary(eth_dev, fd);
> >>> +				if (ret) {
> >>> +					DRV_LOG(ERR, "Failed secondary
> >> map %d",
> >>> +						fd);
> >>> +					goto failed;
> >>> +				}
> >>> +
> >>> +				/* fd is no not used after mapping doorbell */
> >>> +				close(fd);
> >>> +
> >>> +				rte_spinlock_lock(&mana_shared_data-
> >>> lock);
> >>> +				mana_shared_data->secondary_cnt++;
> >>> +				mana_local_data.secondary_cnt++;
> >>> +				rte_spinlock_unlock(&mana_shared_data-
> >>> lock);
> >>> +
> >>> +				rte_eth_copy_pci_info(eth_dev, pci_dev);
> >>> +				rte_eth_dev_probing_finish(eth_dev);
> >>> +
> >>> +				/* Impossible to have more than one port
> >>> +				 * matching a MAC address
> >>> +				 */
> >>> +				continue;
> >>> +			}
> >>> +
> >>> +			eth_dev = rte_eth_dev_allocate(name);
> >>> +			if (!eth_dev) {
> >>> +				ret = -ENOMEM;
> >>> +				goto failed;
> >>> +			}
> >>> +
> >>> +			eth_dev->data->mac_addrs =
> >>> +				rte_calloc("mana_mac", 1,
> >>> +					   sizeof(struct rte_ether_addr), 0);
> >>> +			if (!eth_dev->data->mac_addrs) {
> >>> +				ret = -ENOMEM;
> >>> +				goto failed;
> >>> +			}
> >>> +
> >>> +			rte_ether_addr_copy(&addr, eth_dev->data-
> >>> mac_addrs);
> >>> +
> >>> +			priv->ib_pd = ibv_alloc_pd(ctx);
> >>> +			if (!priv->ib_pd) {
> >>> +				DRV_LOG(ERR, "ibv_alloc_pd failed port %d",
> >> port);
> >>> +				ret = -ENOMEM;
> >>> +				goto failed;
> >>> +			}
> >>> +
> >>> +			/* Create a parent domain with the port number */
> >>> +			attr.pd = priv->ib_pd;
> >>> +			attr.comp_mask =
> >> IBV_PARENT_DOMAIN_INIT_ATTR_PD_CONTEXT;
> >>> +			attr.pd_context = (void *)(uint64_t)port;
> >>> +			priv->ib_parent_pd = ibv_alloc_parent_domain(ctx,
> >> &attr);
> >>> +			if (!priv->ib_parent_pd) {
> >>> +				DRV_LOG(ERR,
> >>> +					"ibv_alloc_parent_domain failed port
> >> %d",
> >>> +					port);
> >>> +				ret = -ENOMEM;
> >>> +				goto failed;
> >>> +			}
> >>> +
> >>> +			priv->ib_ctx = ctx;
> >>> +			priv->port_id = eth_dev->data->port_id;
> >>> +			priv->dev_port = port;
> >>> +			eth_dev->data->dev_private = priv;
> >>> +			priv->dev_data = eth_dev->data;
> >>> +
> >>> +			priv->max_rx_queues = dev_attr.orig_attr.max_qp;
> >>> +			priv->max_tx_queues = dev_attr.orig_attr.max_qp;
> >>> +
> >>> +			priv->max_rx_desc =
> >>> +				RTE_MIN(dev_attr.orig_attr.max_qp_wr,
> >>> +					dev_attr.orig_attr.max_cqe);
> >>> +			priv->max_tx_desc =
> >>> +				RTE_MIN(dev_attr.orig_attr.max_qp_wr,
> >>> +					dev_attr.orig_attr.max_cqe);
> >>> +
> >>> +			priv->max_send_sge = dev_attr.orig_attr.max_sge;
> >>> +			priv->max_recv_sge = dev_attr.orig_attr.max_sge;
> >>> +
> >>> +			priv->max_mr = dev_attr.orig_attr.max_mr;
> >>> +			priv->max_mr_size =
> >> dev_attr.orig_attr.max_mr_size;
> >>> +
> >>> +			DRV_LOG(INFO, "dev %s max queues %d desc %d
> >> sge %d",
> >>> +				name, priv->max_rx_queues, priv-
> >>> max_rx_desc,
> >>> +				priv->max_send_sge);
> >>> +
> >>> +			rte_spinlock_lock(&mana_shared_data->lock);
> >>> +			mana_shared_data->primary_cnt++;
> >>> +			rte_spinlock_unlock(&mana_shared_data->lock);
> >>> +
> >>> +			eth_dev->data->dev_flags |=
> >> RTE_ETH_DEV_INTR_RMV;
> >>> +
> >>> +			eth_dev->device = &pci_dev->device;
> >>> +			eth_dev->data->dev_flags |=
> >>> +				RTE_ETH_DEV_AUTOFILL_QUEUE_XSTATS;
> >>> +
> >> Please do not use the temporary macro. Please review this patch:
> >>
> >> f30e69b41f94 ("ethdev: add device flag to bypass auto-filled queue
> >> xstats")
> >>
> >> This patch requires that per queue statistics are filled in
> >> .xstats_get() by PMD.
> > Thanks for pointing this out.
> >
> > It seems some PMDs are still depending on this flag for xstats.
> >
> > MANA doesn't implement xstats_get() currently, this flag is useful. Is it
> okay to keep using this flag before it's finally the time to remove it from all
> PMDs, or when MANA implements xstats?
> Yes, your xstats doesn't implement now. Per queue stats should be filled in
> xstats API, and the stats API cannot see per queue stats, so stats API in driver
> shouldn't fill it(suggest that delete it from patch 17/18).
> 
> I guess this flag can be removed if PMD does not support xstats.
> >
> >

I don't understand your suggestion. An application can call rte_eth_stats_get() to get port stats, and this will call into stats_get() in the driver, as implemented in patch 17/18.

When flag RTE_ETH_DEV_AUTOFILL_QUEUE_XSTATS  is set, an application can also use rte_eth_xstats_get() to get port stats even the driver doesn't implement xstats_get().