Parav Pandit writes: > + Dave. > > Hi Jiri, Dave, Alex, Kirti, Cornelia, > > Please provide your feedback on it, how shall we proceed? > > Hence, I would like to discuss below options. > > Option-1: mdev index > Introduce an optional mdev index/handle as u32 during mdev create time. > User passes mdev index/handle as input. > > phys_port_name=mIndex=m%u > mdev_index will be available in sysfs as mdev attribute for udev to name the mdev's netdev. > > example mdev create command: > UUID=$(uuidgen) > echo $UUID index=10 > /sys/class/net/ens2f0/mdev_supported_types/mlx5_core_mdev/create > example netdevs: > repnetdev=ens2f0_m10 /*ens2f0 is parent PF's netdevice */ > mdev_netdev=enm10 > > Pros: > 1. mdevctl and any other existing tools are unaffected. > 2. netdev stack, ovs and other switching platforms are unaffected. > 3. achieves unique phys_port_name for representor netdev > 4. achieves unique mdev eth netdev name for the mdev using udev/systemd extension. > 5. Aligns well with mdev and netdev subsystem and similar to existing sriov bdf's. > > Option-2: shorter mdev name > Extend mdev to have shorter mdev device name in addition to UUID. > such as 'foo', 'bar'. > Mdev will continue to have UUID. > phys_port_name=mdev_name > > Pros: > 1. All same as option-1, except mdevctl needs upgrade for newer usage. > It is common practice to upgrade iproute2 package along with the kernel. > Similar practice to be done with mdevctl. > 2. Newer users of mdevctl who wants to work with non_UUID names, will use newer mdevctl/tools. > Cons: > 1. Dual naming scheme of mdev might affect some of the existing tools. > It's unclear how/if it actually affects. > mdevctl [2] is very recently developed and can be enhanced for dual naming scheme. > > Option-3: mdev uuid alias > Instead of shorter mdev name or mdev index, have alpha-numeric name alias. > Alias is an optional mdev sysfs attribute such as 'foo', 'bar'. > example mdev create command: > UUID=$(uuidgen) > echo $UUID alias=foo > /sys/class/net/ens2f0/mdev_supported_types/mlx5_core_mdev/create > example netdevs: > examle netdevs: > repnetdev = ens2f0_mfoo > mdev_netdev=enmfoo > > Pros: > 1. All same as option-1. > 2. Doesn't affect existing mdev naming scheme. > Cons: > 1. Index scheme of option-1 is better which can number large number of mdevs with fewer characters, simplifying the management tool. I believe that Alex pointed out another "Cons" to all three options, which is that it forces user-space to resolve potential race conditions when creating an index or short name or alias. Also, what happens if `index=10` is not provided on the command-line? Does that make the device unusable for your purpose? -- Cheers, Christophe de Dinechin (IRC c3d)
