On Tue, Mar 13, 2018 at 01:50:36PM +0100, Nelio Laranjeiro wrote:
> This patch new file is not compiled yet, it starts a series necessary to
> fix some issues with VF devices.
>
> Signed-off-by: Nelio Laranjeiro <nelio.laranje...@6wind.com>
The fact this new file is not compiled in at this point won't be obvious
when running git bisect and makes validation more difficult. I suggest to
simply merge it into the next patch.
A few more comments on this code below.
> ---
> drivers/net/mlx5/mlx5_vf.c | 134
> +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 134 insertions(+)
> create mode 100644 drivers/net/mlx5/mlx5_vf.c
>
> diff --git a/drivers/net/mlx5/mlx5_vf.c b/drivers/net/mlx5/mlx5_vf.c
Regarding the name of this file, it looks to me like all the enclosed
functions could work equally well with non-VF devices. While this series is
targeted at VFs, internal functions are actually more versatile.
I suggest a more generic name, e.g. "mlx5_nl.c".
> new file mode 100644
> index 000000000..357407f56
> --- /dev/null
> +++ b/drivers/net/mlx5/mlx5_vf.c
> @@ -0,0 +1,134 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2018 6WIND S.A.
> + * Copyright 2018 Mellanox Technologies, Ltd.
> + */
> +
> +#include <linux/rtnetlink.h>
> +#include <linux/netlink.h>
> +
> +#include <rte_netlink.h>
> +
> +#include "mlx5.h"
> +#include "mlx5_utils.h"
> +
> +/* Data exchanged between Netlink library and PMD. */
> +struct mlx5_vf_iface {
> + struct rte_eth_dev *dev; /**< Pointer to Ethernet device. */
> + int iface_idx; /**< Network Interface index. */
> +};
Minor documentation nits here and elsewhere, you should remove the random
capitalization of "Interface", "Message", "Header" and so on in the middle
of sentences.
> +
> +/**
> + * Parse Netlink message to retrieve the interface index.
> + *
> + * @param nh
> + * Pointer to Netlink Message Header.
> + * @param arg
> + * PMD data register with this callback.
> + *
> + * @return
> + * 0 on success, -1 otherwise.
Looks like it only returns 0, never -1.
You should probably describe that ((struct mlx5_vf_iface)arg)->iface_idx is
left to -1 when its index can't be found.
> + */
> +static int
> +mlx5_vf_iface_idx_cb(struct nlmsghdr *nh, void *arg)
> +{
> + struct mlx5_vf_iface *data = arg;
> + struct rte_eth_dev *dev = data->dev;
> + const struct ether_addr *mac = &dev->data->mac_addrs[0];
> + struct ifinfomsg *iface;
> + struct rtattr *attribute;
> + int len;
> +
> + /**
> + * Leave right away if the index does not match its initialised value.
> + * Interface index has already been found.
> + */
> + if (data->iface_idx != -1)
> + return 0;
> + iface = NLMSG_DATA(nh);
> + len = nh->nlmsg_len - NLMSG_LENGTH(sizeof(*iface));
> + for (attribute = IFLA_RTA(iface);
> + RTA_OK(attribute, len);
> + attribute = RTA_NEXT(attribute, len)) {
> + if (attribute->rta_type == IFLA_ADDRESS &&
> + !memcmp(RTA_DATA(attribute), mac, ETHER_ADDR_LEN)) {
Hmm, I'm not sure a matching MAC address is safe enough to determine it's
the right netdevice. Could be a bridge (br0) interface or any other virtual
thing. Although not great, you should probably rely on /sys as in
mlx5_get_ifname().
> +#ifndef NDEBUG
> + struct ether_addr m;
> +
> + memcpy(&m, RTA_DATA(attribute), ETHER_ADDR_LEN);
> + DRV_LOG(DEBUG,
> + "port %u interace %d MAC address"
interace => interface
> + " %02X:%02X:%02X:%02X:%02X:%02X",
> + dev->data->port_id,
> + iface->ifi_index,
> + m.addr_bytes[0], m.addr_bytes[1],
> + m.addr_bytes[2], m.addr_bytes[3],
> + m.addr_bytes[4], m.addr_bytes[5]);
> +#endif
> + data->iface_idx = iface->ifi_index;
> + return 0;
> + }
> + }
> + data->iface_idx = -1;
> + return 0;
> +}
> +
> +/**
> + * Retrieve interface Netlink interface index.
> + *
> + * @param dev
> + * Pointer to Ethernet device.
> + *
> + * @return
> + * Interface index, a negative errno value otherwise and rte_errno is set.
> + */
> +static int
> +mlx5_vf_iface_idx(struct rte_eth_dev *dev)
> +{
> + struct nl_req {
> + struct nlmsghdr hdr;
> + struct rtgenmsg gen;
> + } req = {
> + .hdr = {
> + .nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
> + .nlmsg_type = RTM_GETLINK,
> + .nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP | NLM_F_ROOT,
> + },
> + .gen = {
> + .rtgen_family = AF_UNSPEC,
Extra space before AF_UNSPEC.
> + },
> + };
> + struct mlx5_vf_iface data = {
> + .dev = dev,
> + .iface_idx = -1,
> + };
> + int fd;
> + int ret;
> +
> + fd = rte_nl_init(RTMGRP_LINK);
> + if (fd < 0) {
> + rte_errno = errno;
> + goto error;
> + }
> + ret = rte_nl_send(fd, &req.hdr);
> + if (ret == -1) {
> + rte_errno = errno;
> + goto error;
> + }
> + ret = rte_nl_recv(fd, mlx5_vf_iface_idx_cb, &data);
> + if (ret == -1) {
> + rte_errno = errno;
> + goto error;
> + }
> + rte_nl_final(fd);
> + if (data.iface_idx == -1) {
> + rte_errno = EAGAIN;
> + goto error;
> + }
> + return data.iface_idx;
> +error:
> + if (fd >= 0)
> + rte_nl_final(fd);
> + DRV_LOG(DEBUG, "port %u cannot retrieve Netlink Interface index %s",
> + dev->data->port_id, strerror(rte_errno));
> + return -rte_errno;
> +}
> --
> 2.11.0
>
Due to possible MAC addresses collisions, I suggest a simpler approach:
replacing all this code with a combination of mlx5_get_ifname() and
if_nametoindex(). Thoughts?
--
Adrien Mazarguil
6WIND
