On Fri, 8 Nov 2019 15:40:22 +0000, Parav Pandit wrote: > > The new intel driver has been having a very similar discussion about how to > > model their 'multi function device' ie to bind RDMA and other drivers to a > > shared PCI function, and I think that discussion settled on adding a new bus? > > > > Really these things are all very similar, it would be nice to have a clear > > methodology on how to use the device core if a single PCI device is split by > > software into multiple different functional units and attached to different > > driver instances. > > > > Currently there is alot of hacking in this area.. And a consistent scheme > > might resolve the ugliness with the dma_ops wrappers. > > > > We already have the 'mfd' stuff to support splitting platform devices, maybe > > we need to create a 'pci-mfd' to support splitting PCI devices? > > > > I'm not really clear how mfd and mdev relate, I always thought mdev was > > strongly linked to vfio. > > > Mdev at beginning was strongly linked to vfio, but as I mentioned above it is addressing more use case. > > I observed that discussion, but was not sure of extending mdev further. > > One way to do for Intel drivers to do is after series [9]. > Where PCI driver says, MDEV_CLASS_ID_I40_FOO > RDMA driver mdev_register_driver(), matches on it and does the probe(). Yup, FWIW to me the benefit of reusing mdevs for the Intel case vs muddying the purpose of mdevs is not a clear trade off. IMHO MFD should be of more natural use for Intel, since it's about providing different functionality rather than virtual slices of the same device. > > At the very least if it is agreed mdev should be the vehicle here, then it > > should also be able to solve the netdev/rdma hookup problem too.
