Virtio

• intro

  • virtio devices are implemented over MMIO, Channel I/O and PCI bus transports

  • virtqueue, vring

Document

• initial paper from Rusty Russel: (Rusty, 2008) virtio: Towards a De-Facto Standard For Virtual I/O Devices

• about virtio spec:

  • Virtio spec from OASIS

  • (2014), Standardizing virtio [LWN.net]

• (2010), IBM developer works, Virtio: An I/O virtualization framework for Linux

• CMU 15-412 materials, Virtio: An I/O virtualization framework for Linux

• (2014, devconf.cz), Stefan Hajnoczi. VIRTIO 1.0 - Paravirtualized I/O for KVM and beyond

• Performance comparsion: virtio-blk latency

notes

• paper note: virtio-paper

• virtqueue initialization (e.g. config)

• virtqueue 5 ops 簡介

virtio-blk

• documents

  • virtio blk 流程 (p.18 to 21)

  • (2012) virtio blk performance improvement

  • Virtio-Blk性能加速方案

• bio based virtio-blk guest driver: remove IO scheduling.

• vhost blk host driver: remove host fs layer, no qemu userspace.

Misc

• virtqueue kick: a pio write to a virtio PCI hardware register

  • Programming IO: https://en.wikipedia.org/wiki/Programmed_input/output

  • http://www.linux-kvm.org/page/Virtio/Block/Latency

  • 好吧, 看來 virtqueue kick 就是 trap, vring interrupt 也是一般的 interrupt.

• virtio-ioeventfd (userspace emulation)

  • mailing list discussion

  • patch

  • virtio-pci: Use ioeventfd for virtqueue notify