On Mon, Jul 09, 2018 at 11:57:29AM +0000, Shahaf Shuler wrote:
> Hi Adrien,
>
>
> Thursday, July 5, 2018 11:46 AM, Adrien Mazarguil:
> > Subject: [PATCH v4 07/10] net/mlx5: probe all port representors
> >
> > Probe existing port representors in addition to their master device and
> > associate them automatically.
> >
> > To avoid collision between Ethernet devices, they are named as follows:
> >
> > - "{DBDF}" for master/switch devices.
> > - "{DBDF}_representor_{rep}" with "rep" starting from 0 for port
> > representors.
> >
> > (Patch based on prior work from Yuanhan Liu)
> >
> > Signed-off-by: Adrien Mazarguil <adrien.mazarg...@6wind.com>
> > Signed-off-by: Nelio Laranjeiro <nelio.laranje...@6wind.com>
> > Reviewed-by: Xueming Li <xuemi...@mellanox.com>
> > Cc: Xueming Li <xuemi...@mellanox.com>
> > Cc: Shahaf Shuler <shah...@mellanox.com>
> > --
> > v4 changes:
> >
> > - Fixed domain ID release once the last port using it is closed. Closed
> > devices are not necessarily detached, their presence is not a good
> > indicator. Code was modified to check if they still use their domain IDs
> > before deciding to release it.
<snip>
> > @@ -883,6 +915,41 @@ mlx5_dev_spawn(struct rte_device *dpdk_dev,
> > priv->nl_socket_rdma = mlx5_nl_init(0, NETLINK_RDMA);
> > priv->nl_socket_route = mlx5_nl_init(RTMGRP_LINK,
> > NETLINK_ROUTE);
> > priv->nl_sn = 0;
> > + priv->representor = !!switch_info->representor;
> > + priv->domain_id = RTE_ETH_DEV_SWITCH_DOMAIN_ID_INVALID;
> > + priv->representor_id =
> > + switch_info->representor ? switch_info->port_name : -1;
> > + /*
> > + * Look for sibling devices in order to reuse their switch domain
> > + * if any, otherwise allocate one.
> > + */
> > + i = mlx5_dev_to_port_id(dpdk_dev, NULL, 0);
> > + if (i > 0) {
> > + uint16_t port_id[i];
> > +
> > + i = RTE_MIN(mlx5_dev_to_port_id(dpdk_dev, port_id, i), i);
> > + while (i--) {
> > + const struct priv *opriv =
> > + rte_eth_devices[port_id[i]].data-
> > >dev_private;
> > +
> > + if (!opriv ||
> > + opriv->domain_id ==
> > + RTE_ETH_DEV_SWITCH_DOMAIN_ID_INVALID)
> > + continue;
> > + priv->domain_id = opriv->domain_id;
>
> It looks like for the second port it will use the domain_id of the first
> port. Is that what you intent?
Yes, it's on purpose. Master and representors of a given device must share
the same domain ID to let applications know they can create flow rules to
forward traffic between them all.
> Note - I couldn't test it due to compilation errors:
>
> /.autodirect/swgwork/shahafs/workspace/dpdk.org/drivers/net/mlx5/mlx5_nl.c:
> In function 'mlx5_nl_switch_info_cb':
> /.autodirect/swgwork/shahafs/workspace/dpdk.org/drivers/net/mlx5/mlx5_nl.c:843:8:
> error: 'IFLA_PHYS_PORT_NAME' undecl
> ared (first use in this function)
> case IFLA_PHYS_PORT_NAME:
> ^
> /.autodirect/swgwork/shahafs/workspace/dpdk.org/drivers/net/mlx5/mlx5_nl.c:843:8:
> note: each undeclared identifier is
> reported only once for each function it appears in
> /.autodirect/swgwork/shahafs/workspace/dpdk.org/drivers/net/mlx5/mlx5_nl.c:851:8:
> error: 'IFLA_PHYS_SWITCH_ID' undecl
> ared (first use in this function)
> case IFLA_PHYS_SWITCH_ID:
> ^
>
> My system info:
> NAME="Red Hat Enterprise Linux Server"
> VERSION="7.3 (Maipo)"
> ID="rhel"
> ID_LIKE="fedora"
> VERSION_ID="7.3"
> PRETTY_NAME="Red Hat Enterprise Linux Server 7.3 (Maipo)"
> ANSI_COLOR="0;31"
> CPE_NAME="cpe:/o:redhat:enterprise_linux:7.3:GA:server"
> HOME_URL="https://www.redhat.com/";
> BUG_REPORT_URL="https://bugzilla.redhat.com/";
>
> REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 7"
> REDHAT_BUGZILLA_PRODUCT_VERSION=7.3
> REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
> REDHAT_SUPPORT_PRODUCT_VERSION="7.3"
> Red Hat Enterprise Linux Server release 7.3 (Maipo)
> Red Hat Enterprise Linux Server release 7.3 (Maipo)
OK, I'll redefine in v5 in case they are missing on the host system.
<snip>
> > diff --git a/drivers/net/mlx5/mlx5.h b/drivers/net/mlx5/mlx5.h index
> > 704046270..cc01310e0 100644
> > --- a/drivers/net/mlx5/mlx5.h
> > +++ b/drivers/net/mlx5/mlx5.h
> > @@ -159,6 +159,7 @@ struct priv {
> > struct ibv_context *ctx; /* Verbs context. */
> > struct ibv_device_attr_ex device_attr; /* Device properties. */
> > struct ibv_pd *pd; /* Protection Domain. */
> > + char ibdev_name[IBV_SYSFS_NAME_MAX]; /* IB device name. */
>
>
> Why we need a dedicated entry for the ibdev_name? it is already part of
> priv->ctx->device->name.
Heh, same reason as the next line below, don't forget those damn secondaries
which can't dereference local pointers from the primary process :)
> > char ibdev_path[IBV_SYSFS_PATH_MAX]; /* IB device path for
> > secondary */
<snip>
> > struct rte_eth_dev_info *info)
> > info->speed_capa = priv->link_speed_capa;
> > info->flow_type_rss_offloads = ~MLX5_RSS_HF_MASK;
> > mlx5_set_default_params(dev, info);
> > + info->switch_info.name = dev->data->name;
> > + info->switch_info.domain_id = priv->domain_id;
> > + info->switch_info.port_id = priv->representor_id;
> > + if (priv->representor) {
> > + unsigned int i = mlx5_dev_to_port_id(dev->device, NULL, 0);
> > + uint16_t port_id[i];
> > +
> > + i = RTE_MIN(mlx5_dev_to_port_id(dev->device, port_id, i),
> > i);
> > + while (i--) {
> > + struct priv *opriv =
> > + rte_eth_devices[port_id[i]].data-
> > >dev_private;
> > +
> > + if (!opriv ||
> > + opriv->representor ||
> > + opriv->domain_id != priv->domain_id)
> > + continue;
> > + /*
> > + * Override switch name with that of the master
> > + * device.
> > + */
> > + info->switch_info.name = opriv->dev_data->name;
> > + break;
>
> According to this logic it means once the master device is closed, all the
> representors are no longer belong to the same switch (switch name of each is
> different) which is not correct.
They still share the same domain ID, which is what actually matters. The
switch name is only provided to let applications identify the master
(control) device in case it's needed.
> According to your notes it is possible to close master w/o closing the
> representor.
This allows devices to be probed in any order on a needed basis, not all at
once. It's done on purpose to pave the way for hotplug support.
> Why not just storing the master switch name when probing the representor and
> to use it as is on the dev_info?
The switch name *must* be that of the master device. If the master is not
probed, there can't be a switch name. However there's no real provision for
this in the API, so I chose the most acceptable unique name, which is the
name of the local device. Would you prefer an empty name instead?
Thing is, on mlx5 flow rules can be created directly between representors
without involving the master device. An empty switch name may be misleading
in this respect.
What do you suggest?
--
Adrien Mazarguil
6WIND
