Google Summer of Code 2012: Difference between revisions

From QEMU
(Add Tegra2 emulation as new idea)
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A new API being proposed now can limit the range of memory from which we take the log information and thus makes it possible to control the latency by not trying to handle too many pages at once.
A new API being proposed now can limit the range of memory from which we take the log information and thus makes it possible to control the latency by not trying to handle too many pages at once.
Note: this is not a simple task that you can do by simply following my instructions. Actually I am not 100 percent sure whether this approach will work well because I have not used the new API yet. So applicants need to understand QEMU's live migration correctly by themselves and think whether this proposal can be achieved in 12 weeks before applying for this.
I am offline from March 23 to March 28.


'''Links:'''
'''Links:'''
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'''Details:'''
'''Details:'''
* Component: KVM, kvm-unit-tests, QEMU
* Component: KVM, kvm-unit-tests, QEMU
* Skill level: beginner/intermediate
* Skill level: intermediate/advanced
* Language: C, C++
* Language: C, C++
* Mentor: Takuya Yoshikawa <takuya.yoshikawa__AT__gmail.com>
* Mentor: Takuya Yoshikawa <takuya.yoshikawa__AT__gmail.com>

Revision as of 01:58, 4 March 2012

Introduction

As we did last year, QEMU is going to apply as a mentoring organization for Google Summer of Code 2012. This page contains our ideas list and some additional information for students and mentors.

Please note that QEMU, as a GSoC organization, also includes the following projects:

  • The Linux Kernel's KVM module
  • Libvirt, the virtualization library (pending OK from libvirt people)

Organization

Any Question, request or problem regarding QEMU in GSoC, please contact the following people.

Find Us

GSoC important pages

Information for students

We require students to provide (at least) the following information in their applications:

  • Contact information (email, irc nick, phone number)
  • A general personal description (skills, past experiences and possible open source contributions)
  • Why QEMU and why this project
  • A detailed description of the approach the student will take

Please get in touch before applying so we can arrange for an IRC interview and get to know each other. Students who do not contact the mentor cannot be accepted.

VERY IMPORTANT: Submitting a patch and having it merged by QEMU or KVM increases your chances of being accepted.

Projects Ideas

This is the listing of suggested project ideas. It might be useful to check last year's page. Also note that students are free to suggest their own projects.

== TITLE ==
 
 '''Summary:''' Short description of the project
 
 Detailed description of the project.
 
 '''Links:'''
 * Wiki links to relevant material
 * External links to mailing lists or web sites
 
 '''Details:'''
 * Component: QEMU or KVM or libvirt
 * Skill level: beginner or intermediate or advanced
 * Language: C
 * Mentor: Email address and IRC nick
 * Suggested by: Person who suggested the idea

git style front-end to QEMU

Summary: Provide a git like front-end for QEMU that allows for enumerating running instances and manipulating them from a command line.

Starting in the 1.0 release, we freed up the qemu executable name in order to allow a script to be introduced that would provide an easier to use scripting interface to QEMU. It would provide a series of sub commands like list, create, shutdown, etc. that would provide an alternative command line front-end to QEMU that the qemu-system executables.

Links:

Details:

  • Component: QEMU
  • Skill level: beginner
  • Language: Python
  • Mentor: Anthony Liguori <aliguori@us.ibm.com> (IRC: aliguori)
  • Suggested by: Anthony Liguori

Finish OS X Virtualization Support

Summary: Finish up the last remaining pieces to enable running Mac OS X guests on Linux on Mac hardware

There are a few remaining pieces of work to allow virtualizing OS X guests in KVM. A few devices still need to be up-streamed. Testing needs to be done, and likely some new code will have to be written to fix certain bugs. The last time anyone was successful in running OS X in KVM was OS X 10.4. Support for newer versions would be required. The most recently updated patches that I know of would be in the OpenSUSE src rpm for the kvm package.

Links:

Details:

  • Component: QEMU/KVM
  • Skill level: intermediate/advanced
  • Language: C
  • Mentor: iggy, Alexander Graf
  • Suggested by: iggy

In-process NBD server

Summary: Integrate qemu-nbd server functionality into qemu so disk images can be accessed remotely while the VM is running

The qemu-nbd utility is a stand-alone Network Block Device server which exports disk images (qcow2, qed, vmdk, etc). Linux has an NBD driver, this makes it possible to attach NBD devices like iSCSI or ATA-over-Ethernet volumes and operate on them like local block devices using mkfs, mount, and other common tools.

It is not safe to run qemu-nbd while the VM is running because the disk image could be corrupted by simultaneous updates or read access could give inconsistent results. The goal of this project is to make the qemu-nbd functionality available for a running VM by integrating it into qemu proper.

New QEMU monitor commands must be added to allow disk images to be exported from inside qemu while the VM is running. For safety the in-process NBD server would only allow read access. It should be possible to export not just top-level image files but also backing files.

This new feature will enable online backup, data migration, and other interesting scenarios.

Links:

Details:

  • Component: QEMU
  • Skill level: intermediate
  • Language: C
  • Mentor: Stefan Hajnoczi <stefanha@gmail.com>, 'stefanha' on IRC
  • Suggested by: Stefan Hajnoczi

Partial device emulation in KVM

Summary: Add support for and benchmark partial device emulation in KVM

When using KVM, almost all device emulation is done in user space (QEMU). While this is really nice from an architecture point of view, it's not the greatest thing when it comes to latencies. Some devices like IDE, VGA, HPET have very hot path registers that can be easily emulated in the kernel (KVM), with all heavier operations going to user space.

This project is about prototyping such partial device emulation to see if it actually does give us speedups. If you manage to show great performance improvements with it, we would then work on finding clean solutions to integrate this upstream and also push it upstream.

With a bit of luck, we might end up getting significant speedups to KVM!


Mid-term goal: Implement prototype for one of the 3 mentioned devices, do benchmarks

Final goal: If the prototype was successful, work on upstreaming it, if not, pick another device and implement a prototype for that


Links:

Details:

IA64 emulation

Summary: Add support for IA64 system emulation in QEMU

The KVM project had a working IA64 port that was able to run a virtualized system with KVM and QEMU as it was back in those times. If we take the hardware emulation from that and add CPU emulation to the mix, we should get a workable solution for IA64 emulation.

Because most applicants won't own their own IA64 box, I will provide access to one so that we can rule out the CPU emulation bits of the equation and focus on getting the device model working well enough to at least run the firmware as a first target milestone. CPU emulation comes second.

Mid-term goal: Make (current) QEMU work on IA64 with KVM

Final goal: Implement CPU emulation to a point where TianoCore works


Links:


Details:

  • Component: QEMU
  • Skill level: intermediate/advanced
  • Language: C, IA64 asm
  • Mentor: Alexander Graf, Jakub Jermar
  • Suggested by: Jakub Jermar

Live migration with new GET_DIRTY_LOG

Summary: Improve QEMU's live migration with a new GET_DIRTY_LOG which makes dirty page logging more flexible.

Dirty page logging is a technique used for tracking modified guest memory during live migration or VGA emulation. KVM has an API, called GET_DIRTY_LOG, which can be used for this: the caller gets the logged information in a bitmap that indicates which pages have become dirty since the last call.

One problem we are facing about this is that this API needs to hold a lock, which is needed to do some mmu related work, too long if a lot of guest pages are dirty and this may cause noticeable latency in the guest.

A new API being proposed now can limit the range of memory from which we take the log information and thus makes it possible to control the latency by not trying to handle too many pages at once.

Note: this is not a simple task that you can do by simply following my instructions. Actually I am not 100 percent sure whether this approach will work well because I have not used the new API yet. So applicants need to understand QEMU's live migration correctly by themselves and think whether this proposal can be achieved in 12 weeks before applying for this.

I am offline from March 23 to March 28.

Links:

Details:

  • Component: KVM, kvm-unit-tests, QEMU
  • Skill level: intermediate/advanced
  • Language: C, C++
  • Mentor: Takuya Yoshikawa <takuya.yoshikawa__AT__gmail.com>
  • Suggested by: Takuya Yoshikawa

Tegra2 emulation

Summary: Emulate the Nvidia Tegra2 SoC sufficiently for Linux to boot.

QEMU can already emulate ARM Cortex-A9 cores. What's missing is Tegra-specific devices (like framebuffer), glueing them together to a QOM System-on-Chip object and some machine function that instantiates this SoC (e.g., Toshiba AC100). This may involve some reading of Linux/U-Boot/etc. source code and/or debugging in QEMU what memory addresses the binaries are trying to access and what devices that corresponds to.

Ubuntu and openSUSE have Linux images for the AC100 that could be used for testing.

Links:

Details:

  • Component: QEMU
  • Skill level: advanced
  • Language: C, possibly ARM assembler
  • Mentor: Andreas Färber <afaerber@suse.de> (IRC: afaerber)
  • Suggested by: Andreas Färber