On Thu, Feb 04, 2016 at 01:30:35PM +0000, Ferruh Yigit wrote: > On Tue, Jan 19, 2016 at 01:29:32PM +0200, Panu Matilainen wrote: > > On 01/19/2016 11:59 AM, Ferruh Yigit wrote: > >> On Mon, Jan 18, 2016 at 11:20:02AM -0500, Aaron Conole wrote: > >>> Ferruh Yigit <ferruh.yigit at intel.com> writes: > >>>> This work is to make DPDK ports more visible and to enable using common > >>>> Linux tools to configure DPDK ports. > >>> > >>> This is a good goal. Only question - why use an additional kernel module > >>> to do this? Is it _JUST_ for ethtool support? > >> > >> Kernel module used to create/destroy Linux net_devices, and module has a > >> simple > >> driver for that device which only handles control messages by passing them > >> into > >> userspace. > >> > >> To represent DPDK ports as Linux net_devices we need kernel support. > >> > >>> I think the other stuff > >>> can be accomplished using netlink sockets + messages, no? > >> > >> Netlink sockets just used to communicate kernel-space - user-space, this > >> is not > >> why we need a kernel module, for example this communication is implemented > >> in > >> original KNI as part of FIFO. > >> > >>> The only > >>> trepidation I would have with something like this is the support from > >>> major vendors - out of tree modules are not generally supportable. Might > >>> be good to get some of the ethtool commands as netlink messages as well, > >>> then it is supportable with no 3rd party kernel modules. > >> > >> Yes, there is a out of three module problem for some distros, but > >> unfortunately > >> we are not able to find a solution for this case without an external > >> kernel module. > >> > >> This patch is still an RFC and if we receive suggested solution without a > >> kernel > >> module, we can work on it together. > > > > If it has to be in the kernel then you need to find a design that is > > upstreamable. Out of tree kernel modules are not a solution, they're a > > problem that people are working on eliminating. > > > > Hi Stephen, and other Linux experts in the mail list,
forget to add Stephen Hemminger to cc, doing now. > > Can you please help finding a upstreamable solution for kernel control path? > > Mainly what we are looking for is userspace network driver support in kernel, > similar to what FUSE does but a much simple version. > > Above KCP module basically does this, by having a network driver which > passing requests to userspace network driver, but it is not generic enough. > > I wonder if it is possible make it more generic by extending rtnetlink > support: > 1- Add a new network driver to Linux (or update existing one like tun) to > forward requests, get responses. > 2- Extend rtnelink to support to attach any userspace driver to this device? > (ip link set <device> uspace <?> ?) > > Does this make sense? > > rtnetlink already supports creating interfaces, and it provides kernel/user > space communication, > with "attach" support interface learns about it's peer in usersppace and can > communicate. > > FUSE like communication method also can be alternative to transfer request > and responses, but since rtnelink support exists, no need to create something > new think. > > Thanks, > ferruh >