We are implementing a driver for a PCIe card that runs Linux. This card needs "virtual" network/disk/console devices, so we have reused the virtio devices on on the card and provided a host backend that interacts with the virtio devices through the card's driver.
this approach is very much like what was proposed on this thread http://permalink.gmane.org/gmane.linux.ports.sh.devel/10379 We will posting the driver soon, so perhaps I am jumping the gun with my question below about replacing our backend with vhost. It is possible for vhost (along with vhost-net in the case of virtio-net) to serve as the backend. The copy between virtio buffers and skbs happens in the tun/tap driver which means tun/tap may need to use a HW DMA engine (the card has one) for copy across the bus to get close to the full PCIe bandwidth. tun/tap was probably never designed for this use case, but reusing vhost does simplify our backend since it is now only involved in setup and potentially has a performance/memory footprint advantage due to avoiding context switches/intermediate buffer copy and this idea can be generalized to other cards as well. Comments/suggestions ? Thanks, Nikhil _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
