Apologies for the late reply - this got lost in the vacation email backlog. On Mon, 26 Aug 2024 at 10:27, Dennis Dalessandro <dennis.dalessandro@xxxxxxxxxxxxxxxxxxxx> wrote: > > On 7/31/24 4:02 PM, Doug Miller wrote: > > I am working on SR-IOV support for a new adapter which has shared > > resources between the PF and VFs and requires an out-of-band (outside It would have been a good idea to let people know what "PF" and "VF" means to avoid confusion. > > the adapter) communication mechanism to manage those resources. I have > > been looking at RPMSG as a mechanism to communicate between the driver > > on a guest (VM) and the driver on the host OS (which "owns" the > > resources). It appears to me that virtio is intended for communication > > between guests and host, and RPMSG over virtio is what I want to use. > > Virtio is definitely the standard way to convey information between a host and a guest. You can specify as many virtqueues as needed (in-band and out-of-band) and it is widely supported. What information is conveyed by the virtqueues and how it gets conveyed is entirely up to the use case. Have a look at the specification of existing virtio drivers to get a better idea [1]. If the driver you are working with hasn't been standardised, I highly encourage you to submit a draft for it. If it has then add to the current specification. All that said, you could use RPMSG as the protocol that runs on top of the virtqueues - that should be fairly easy to do. Thanks, Mathieu [1]. https://docs.oasis-open.org/virtio/virtio/v1.2/csd01/virtio-v1.2-csd01.html > > Can anyone confirm that RPMSG is capable of doing what we need? If so, > > I'll need some help figuring out how to use that from kernel device > > drivers (I've not been able to find any examples of doing the > > service/device side). If not, is there some other facility that is > > better suited? > > Hi Bjorn and Mathieu, any advice here for Doug? Adding linux-rdma folks as that > is where this will eventually target. > > -Denny >
