Google Summer of Code 2011: Difference between revisions

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The aim is to design a safe in-place converter to change from QCOW2 to QED (and vice versa) without copying image data.  This will require understanding the QCOW2 and QED image formats and how they organize image data.  You will need to carefully design the process so image data is never at risk in the event of a crash during conversion.  Finally, you will be responsible for adding tests that defend this feature to the ''qemu-iotests'' suite.
The aim is to design a safe in-place converter to change from QCOW2 to QED (and vice versa) without copying image data.  This will require understanding the QCOW2 and QED image formats and how they organize image data.  You will need to carefully design the process so image data is never at risk in the event of a crash during conversion.  Finally, you will be responsible for adding tests that defend this feature to the ''qemu-iotests'' suite.
'''Links:'''
* http://people.gnome.org/~markmc/qcow-image-format.html
* [[Features/QED]]


'''Please get in touch before applying''' so we can chat about your ideas and get to know each other.
'''Please get in touch before applying''' so we can chat about your ideas and get to know each other.

Revision as of 13:15, 29 January 2011

Introduction

As we did last year, QEMU is going to apply as a mentoring organization for Google Summer of Code 2011. 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 on GSoC 2011, please contact one of 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

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.

QCOW2 <-> QED image converter

Summary: Design and implement an in-place disk image converter that safely and efficiently changes between the QCOW2 and QED image formats.

QEMU supports several disk image formats that make it possible to manage and share virtual machine disk images as files. The well known formats include qcow2 (QEMU) and vmdk (VMware), and the QEMU Enhanced Disk (QED) format has pushed new levels of performance.

In order for users to go between formats, the qemu-img convert command reads a disk image in one format and outputs it in another format. This has two limitations:

  1. Twice the amount of space is required since both the old and the new image are kept around.
  2. Copying data is slow for large images.

The aim is to design a safe in-place converter to change from QCOW2 to QED (and vice versa) without copying image data. This will require understanding the QCOW2 and QED image formats and how they organize image data. You will need to carefully design the process so image data is never at risk in the event of a crash during conversion. Finally, you will be responsible for adding tests that defend this feature to the qemu-iotests suite.

Links:

Please get in touch before applying so we can chat about your ideas and get to know each other.

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

Tracepoint support for the gdbstub

Recent gdb versions allow to define ad-hoc tracepoints that are able to record memory content or register states whenever the target code hits them. This is supposed to happen non-intrusively, while the target is executing (almost) as normal. QEMU could serve as a nice backend for gdb when it comes to using such dynamic tracepoints for (guest) kernel debugging. In contrast to approaches like kgtp running inside the guest kernel, QEMU is able to perform this in hypervisor context, at most requiring to insert breakpoints into guest visible memory.

In this project, the QEMU gdbstub shall be extended with support for tracepoints. Architecture specific parts shall at least support x86 guests. Tracepoints shall be usable both in emulation and KVM mode. Extending the KVM kernel services to accelerate tracepoints is not required in this first step. See gdb documentation and specifically the gdb remote protocol for further details.

  • Component: QEMU
  • Skill level: medium..high
  • Language: C
  • Mentor: Jan Kiszka <jan.kiszka@web.de>
  • Suggested by: Jan Kiszka <jan.kiszka@web.de>
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