The virtio paravirtualized I/O interfaces have been widely used in Linux and QEMU. Rusty Russell maintained a specification that the community worked around, but has now kicked off standardization through the OASIS standards body.
Follow virtio specification activity and participate on the VIRTIO Technical Committee page.
Today virtio devices include block (disk), SCSI, net (NIC), rng (random number generator), serial, and 9P (host<->guest filesystem). These devices can operate over PCI (used by x86 KVM), MMIO (used for ARM), and other transports.
I'm participating in the VIRTIO TC and hope this new level of virtio activity leads to even wider adoption of open source virtualized I/O devices.