In this post I'd like to discribe the current situtation with Virtio based IO in KVM and give some ways of improvements.
Firstly I'd like to explain what is Virtio and how it works.
Virtio is acronim from Virtualization Input Output.
Virtio is a set of device drivers which implements paravirtualized logic for device representation.
If virtio device attached to the virtual machine (VM), VM starts to now that it is running in virtual environment.
The design of each virtio device is shown at the figure below.
Virtio provides set of devices necessary for productive work:
Logical block scheme is shown at the figure below.
Lets discover the implementation of virtio stack.
There are 2 options. First it is implemented through user space workflow over QEMU.Second is VHOST implementation which directly redirects calls from guest kernel to host kernel and reduce significant overhead due context swithces and global mutexes still existing in QEMU core.
Block device scheme is shown at the figure below.
Its not hard to see how much overhead reduced.
The similar scheme is implemented for networking.
RedHat Enterprise Virtualization seminar
A few fotos from RH seminar.
A few photos 2 @ Edinburgh, UK
A few fotos of China, Shenzhen
Panaramic photo at beach
From the sky
A few photos @ Edinburgh, UK
A few notes about S.O.R.M. in Russia
Basically if translate the description it will look the following way:
S.O.R.M - is the system of technical solutions to provide the functions of crime detection
There are 3 reincornations of this law:
1. First was oldest one and oriented on phone traffic analysis including SMS/MMS and simple paging messages. It was officially published in 1996. As a result all phone operators had to setup environment for federal services to be able to check all voice and messaging traffic
2. Second reincornation was oriented on internet traffic interception and analysis and was officially published in 2000
3. The last reincornation of this law was officially published a few days ago and's effect date June 2014
Let me summarize: starting from June 2014 all telecom operators will must monitor all kind of activities of their clients.
What is the difference between S.O.R.M. in Russia and similar systems in other contries? I personally think that the difference is not very big, but this is not officially published and not conflicting with countries constitutions