[Qemu-devel] [RFC PATCH 0/9] Add colo-proxy based on netfilter

[Zhang Chen]

Hi,all

This patch add an colo-proxy object, COLO-Proxy is a part of COLO,
based on qemu netfilter and it's a plugin for qemu netfilter. the function
keep Secondary VM connect normal to Primary VM and compare packets 
sent by PVM to sent by SVM.if the packet difference,notify COLO do
checkpoint and send all primary packet has queued.

You can also get the series from: 

https://github.com/zhangckid/qemu/tree/colo-proxy-V1

Usage:

primary:
-netdev tap,id=bn0 -device e1000,netdev=bn0
-object colo-proxy,id=f0,netdev=bn0,queue=all,mode=primary,addr=ip:port

secondary:
-netdev tap,id=bn0 -device e1000,netdev=bn0
-object colo-proxy,id=f0,netdev=bn0,queue=all,mode=secondary,addr=ip:port

NOTE:
queue must set "all". See enum NetFilterDirection for detail.
colo-proxy need queue all packets
colo-proxy V1 just a demo of colo proxy,not pass test with colo upstream


## Background

COLO FT/HA (COarse-grain LOck-stepping Virtual Machines for Non-stop Service)
project is a high availability solution. Both Primary VM (PVM) and Secondary VM
(SVM) run in parallel. They receive the same request from client, and generate
responses in parallel too. If the response packets from PVM and SVM are
identical, they are released immediately. Otherwise, a VM checkpoint (on 
demand)is conducted.

Paper:
http://www.socc2013.org/home/program/a3-dong.pdf?attredirects=0

COLO on Xen:
http://wiki.xen.org/wiki/COLO_-_Coarse_Grain_Lock_Stepping

COLO on Qemu/KVM:
http://wiki.qemu.org/Features/COLO

By the needs of capturing response packets from PVM and SVM and finding out
whether they are identical, we introduce a new module to qemu networking 
called colo-proxy.


v1:
 initial patch.



zhangchen (9):
  Init colo-proxy object based on netfilter
  jhash: add linux kernel jhashtable in qemu
  colo-proxy: add colo-proxy framework
  colo-proxy: add colo-proxy setup work
  net/colo-proxy: add colo packet handler
  net/colo-proxy: add packet forward function
  net/colo-proxy: add packet enqueue and handle function
  net/colo-proxy: enqueue primary and secondary packet
  net/colo-proxy: add packet compare and notify checkpoint

 include/qemu/jhash.h |  52 ++++
 net/Makefile.objs    |   1 +
 net/colo-proxy.c     | 745 +++++++++++++++++++++++++++++++++++++++++++++++++++
 net/colo-proxy.h     | 124 +++++++++
 qemu-options.hx      |   4 +
 vl.c                 |   3 +-
 6 files changed, 928 insertions(+), 1 deletion(-)
 create mode 100644 include/qemu/jhash.h
 create mode 100644 net/colo-proxy.c
 create mode 100644 net/colo-proxy.h

-- 
1.9.1