Thursday, 18 April 2019

What's new in VIRTIO 1.1?

The VIRTIO 1.1 specification has been published! This article covers the major new features in this specification.

New Devices

The following new devices are defined:

  • virtio-input is a Linux evdev input device (mouse, keyboard, joystick)
  • virtio-gpu is a 2D graphics device (with 3D support planned)
  • virtio-vsock is a host<->guest socket communications device
  • virtio-crypto is a cryptographic accelerator device

New Device Features

virtio-net

virtio-blk

virtio-balloon

New Core Features

There is a new virtqueue memory layout called packed virtqueues. The old layout is called split virtqueues because the avail and used rings are separate from the descriptor table. The new packed virtqueue layout uses just a single descriptor table as the single ring. The layout is optimized for a friendlier CPU cache footprint and there are several features that devices can exploit for better peformance.

The VIRTIO_F_NOTIFICATION_DATA feature is an optimization mainly for hardware implementations of VIRTIO. The driver writes extra information as part of the Available Buffer Notification. Thanks to the information included in the notification, the device does not need to fetch this information from memory anymore. This is useful for PCI hardware implementations where minimizing DMA operations improves performance significantly.

Thursday, 28 February 2019

QEMU accepted into Google Summer of Code and Outreachy 2019

QEMU is participating in the Google Summer of Code and Outreachy open source internship programs again this year. These 12-week, full-time, paid, remote work internships allow people interested in contributing to QEMU get started. Each intern works with one or more mentors who can answer questions and are experienced developers. This is a great way to try out working on open source if you are considering it as a career.

For more information (including eligibility requirements), see our GSoC and our Outreachy pages.

Friday, 25 January 2019

VIRTIO 1.1 is available for public review until Feb 21st 2019

The VIRTIO 1.1 specification for paravirtualized I/O devices includes the new packed vring layout and the GPU, input, crypto, and socket device types. In addition to this there are other improvements and new features in the specification. The new vring layout will increase performance and offers new features that devices can take advantage of.

You can review the specification and post comments until February 21st 2019: VIRTIO 1.1 csprd01.

Sunday, 6 January 2019

mute-thread: a script to mute email threads with notmuch

Ever get included on an email thread that isn't relevant? It can be distracting to see new emails appear on a thread you already know is not interesting. You could mark them as read manually, but that is tedious.

This mute-thread script silences email threads that you don't want to read, even after new emails are received.

Download it here.

Setup

It relies on the awesome notmuch(1) email utility, so make sure you have that set up in order to use this script.

The following .muttrc macro integrates this with the mutt(1) email client. When you press M the entire email thread is muted:

macro index M "<enter-command>unset wait_key<enter><pipe-message>~/.mutt/mute-thread add<enter><enter-command>set wait_key<enter><read-thread>" "Mute thread"

After fetching new emails, run notmuch and then mute-thread apply.

Unmuting threads

If you change your mind, run mute-thread remove MESSAGE-ID to unmute a thread again. Future emails will not be silenced.

Wednesday, 28 November 2018

Software Freedom Conservancy donations are being matched again!

Donations to Software Freedom Conservancy, the charity that acts as the legal home for QEMU and many other popular open source projects that don't run their own foundations or charities, are being matched again this year. That means your donation is doubled thanks to a group of donors who have pledged to match donations.

Software Freedom Conservancy helps projects with the details of running an open source project (legal advice, handling expenses, organizing conferences, etc) as well as taking a leading position on open source licensing and enforcement. Their work is not-for-profit and in the interest of the entire open source community.

If you want more projects like QEMU, Git, Samba, Inkscape, and Selenium to succeed as healthy open source communities, then donating to Software Freedom Conservancy is a good way to help.

Find out about becoming a Supporter here.

Tuesday, 27 November 2018

QEMU Advent Calendar 2018 is coming!

QEMU Advent Calendar is running again this year. Each day from December 1st through 24th a surprise QEMU disk image will be released for your entertainment.

Check out the website on December 1st for the first disk image:

https://www.qemu-advent-calendar.org/2018/

Thomas Huth is organizing QEMU Advent Calendar 2018 with the help of others from the QEMU community. If you want to contribute a disk image, take a look at the call for images email.

Sunday, 4 November 2018

Video and slides available for "Security in QEMU"

I gave a talk about security in QEMU at KVM Forum 2018. It covers the architecture of QEMU and focusses on the attack surfaces that are exposed to guests. I hope it will be useful to anyone auditing or writing device emulation code. It also describes the key design principles for isolating the QEMU process and limiting the damage that can be done if a guest escapes.

The video of the talk is now available:

The slides are available here (PDF).