RE: [PATCH net-next 06/19] net/mlx5: Add support for mediated devices in switchdev mode

[Parav Pandit <parav@mellanox.com>]

> -----Original Message-----
> From: Jiri Pirko <jiri@resnulli.us>
> Sent: Friday, November 8, 2019 10:23 AM
> To: Parav Pandit <parav@mellanox.com>
> Cc: alex.williamson@redhat.com; davem@davemloft.net;
> kvm@vger.kernel.org; netdev@vger.kernel.org; Saeed Mahameed
> <saeedm@mellanox.com>; kwankhede@nvidia.com; leon@kernel.org;
> cohuck@redhat.com; Jiri Pirko <jiri@mellanox.com>; linux-
> rdma@vger.kernel.org; Vu Pham <vuhuong@mellanox.com>
> Subject: Re: [PATCH net-next 06/19] net/mlx5: Add support for mediated
> devices in switchdev mode
> 
> Fri, Nov 08, 2019 at 05:03:13PM CET, parav@mellanox.com wrote:
> >
> >
> >> -----Original Message-----
> >> From: Jiri Pirko <jiri@resnulli.us>
> >> Sent: Friday, November 8, 2019 4:33 AM
> >> To: Parav Pandit <parav@mellanox.com>
> >> Cc: alex.williamson@redhat.com; davem@davemloft.net;
> >> kvm@vger.kernel.org; netdev@vger.kernel.org; Saeed Mahameed
> >> <saeedm@mellanox.com>; kwankhede@nvidia.com; leon@kernel.org;
> >> cohuck@redhat.com; Jiri Pirko <jiri@mellanox.com>; linux-
> >> rdma@vger.kernel.org; Vu Pham <vuhuong@mellanox.com>
> >> Subject: Re: [PATCH net-next 06/19] net/mlx5: Add support for
> >> mediated devices in switchdev mode
> >>
> >> Thu, Nov 07, 2019 at 05:08:21PM CET, parav@mellanox.com wrote:
> >> >From: Vu Pham <vuhuong@mellanox.com>
> >>
> >> [...]
> >>
> >>
> >> >+static ssize_t
> >> >+max_mdevs_show(struct kobject *kobj, struct device *dev, char *buf) {
> >> >+	struct pci_dev *pdev = to_pci_dev(dev);
> >> >+	struct mlx5_core_dev *coredev;
> >> >+	struct mlx5_mdev_table *table;
> >> >+	u16 max_sfs;
> >> >+
> >> >+	coredev = pci_get_drvdata(pdev);
> >> >+	table = coredev->priv.eswitch->mdev_table;
> >> >+	max_sfs = mlx5_core_max_sfs(coredev, &table->sf_table);
> >> >+
> >> >+	return sprintf(buf, "%d\n", max_sfs); } static
> >> >+MDEV_TYPE_ATTR_RO(max_mdevs);
> >> >+
> >> >+static ssize_t
> >> >+available_instances_show(struct kobject *kobj, struct device *dev,
> >> >+char *buf) {
> >> >+	struct pci_dev *pdev = to_pci_dev(dev);
> >> >+	struct mlx5_core_dev *coredev;
> >> >+	struct mlx5_mdev_table *table;
> >> >+	u16 free_sfs;
> >> >+
> >> >+	coredev = pci_get_drvdata(pdev);
> >> >+	table = coredev->priv.eswitch->mdev_table;
> >> >+	free_sfs = mlx5_get_free_sfs(coredev, &table->sf_table);
> >> >+	return sprintf(buf, "%d\n", free_sfs); } static
> >> >+MDEV_TYPE_ATTR_RO(available_instances);
> >>
> >> These 2 arbitrary sysfs files are showing resource size/usage for the
> >> whole eswitch/asic. That is a job for "devlink resource". Please implement
> that.
> >>
> >Jiri,
> >This series is already too long. I will implement it as follow on. It is already
> in plan.
> >However, available_instances file is needed regardless of devlink resource,
> as its read by the userspace for all mdev drivers.
> 
> If that is the case, why isn't that implemented in mdev code rather than
> individual drivers? I don't understand.
>
It should be. It isn't yet.
It is similar to how phys_port_name preparation was done in legacy way in individual drivers and later on moved to devlink.c
So some other time, can move this to mdev core.

 
> 
> >
> >>
> >> >+
> >> >+static struct attribute *mdev_dev_attrs[] = {
> >> >+	&mdev_type_attr_max_mdevs.attr,
> >> >+	&mdev_type_attr_available_instances.attr,
> >> >+	NULL,
> >> >+};
> >> >+
> >> >+static struct attribute_group mdev_mgmt_group = {
> >> >+	.name  = "local",
> >> >+	.attrs = mdev_dev_attrs,
> >> >+};
> >> >+
> >> >+static struct attribute_group *mlx5_meddev_groups[] = {
> >> >+	&mdev_mgmt_group,
> >> >+	NULL,
> >> >+};
> >>
> >> [...]