On Tue, Dec 04, 2018 at 02:04:16PM +0200, Gal Pressman wrote: > Hello all, > The following patchset introduces the Elastic Fabric Adapter (EFA) driver, that > was pre-announced by Amazon [1]. > > EFA is a networking adapter designed to support user space network > communication, initially offered in the Amazon EC2 environment. First release > of EFA supports datagram send/receive operations and does not support > connection-oriented or read/write operations. > > EFA supports unreliable datagrams (UD) as well as a new unordered, scalable > reliable datagram protocol (SRD). SRD provides support for reliable datagrams > and more complete error handling than typical RD, but, unlike RD, it does not > support ordering nor segmentation. A new queue pair type, IB_QPT_SRD, is added > to expose this new queue pair type. > User verbs are supported via a dedicated userspace libfabric provider. > Kernel verbs and in-kernel services are initially not supported. There are some general expectations for new drivers in rdma you should be aware of.. 1) Accepting usnic to RDMA is widely regarded as a mistake. This means that future drivers that do not implement 'enough' common verbs are not likely to be accepted, as they are not RDMA devices. I'm worried this driver doesn't cross the threshold. 2) Any change to common verbs must be supported by full public documentation good enough to allow another implementation. So most likely the IB_QPT_SRD has to go away (this is a NAK). Driver specific QP types can be implemented via driver udata. 3) We need to see the userspace for new drivers. A RDMA driver that doesn't provide a useful rdma-core provider is deeply suspect as not crossing the #1 threshold. Jason
