On Wed, Oct 28, 2020 at 04:50:36PM +0100, Arnd Bergmann wrote: > I think we should try to do something on top of the PCIe endpoint subsystem > to make it work across arbitrary combinations of host and device > implementations, > and provide a superset of what the MIC driver, (out-of-tree) Bluefield > endpoint > driver, and the NTB subsystem as well as a couple of others used to do, > each of them tunneling block/network/serial/... over a PCIe link of some > sort, usually with virtio.
VOP is not PCIe-specific (as demonstrated by the vop-loopback patches I posted a while ago [1]), and it would be a shame for a replacement to be tied to the PCIe endpoint subsystem. There are many SOCs out there which have multiple Linux-capable processors without cache-coherency between them. VOP is (or should I say was since I guess it's being deleted) the closest we have in mainline to easily get generic virtio (and not just rpmsg) running between these kind of Linux instances. If a new replacement framework were to be PCIe-exclusive then we'd have to invent one more framework for non-PCIe links to do pretty much the same thing. [1] https://lore.kernel.org/lkml/20190403104746.16063-1-vincent.whitchu...@axis.com/
