FWN/Issue168

Fedora Weekly News Issue 168

Welcome to Fedora Weekly News Issue 168 for the week ending March 22nd, 2009.

http://fedoraproject.org/wiki/FWN/Issue168

With the Fedora 11 Beta release slipping by one week Announcements reminds the community about "FUDCon Berlin 2009". In PlanetFedora the recent Red Hat patent acquisitions are among several topics covered. Ambassadors reports on the OLPC XO work at Rochester Institute of Technology. QualityAssurance gets excited about "Test Days" for DeviceKit, Xfce and an upcoming one for nouveau. Developments reflects a lot of anxious upgrading and "How to Open ACLs and Find Non-responsive Maintainers". Translation notes the "Upgraded Transifex" and translation to Cornish. Infrastructure advises in "Change Requests" that the infra team is in freeze and lists all the approved recent changes and hotfixes. Controversy rages in "Artwork" over the choice of Greek temple imagery. Yet again SecurityAdvisories lists packages that you want, really, really want. Virtualization worries about "More Flexible x86 Emulator Choice". Needless to say there's lots more to read this week!

If you are interested in contributing to Fedora Weekly News, please see our 'join' page. We welcome reader feedback: fedora-news-list@redhat.com

FWN Editorial Team: Pascal Calarco, Oisin Feeley, Huzaifa Sidhpurwala

Announcements

In this section, we cover announcements from the Fedora Project.

http://www.redhat.com/archives/fedora-announce-list/

http://www.redhat.com/archives/fedora-devel-announce/

https://fedoraproject.org/wiki/Events

Contributing Writer: Max Spevack

Fedora 11

Jesse Keating announced that the Beta of Fedora 11 will slip one week, due to some issues with both PPC and anaconda. The new Beta release date is March 31.

FUDCon Berlin 2009

Max Spevack reminded the community about FUDCon Berlin 2009, including registration, lodging, and speaking opportunities.

Upcoming Events

March 23-29: LUGM OpenWeek in Manipal, India.

March 25: Document Freedom Day in Kolkata, India.

March 25: Document Freedom Day in Opera, Italy.

March 26: Infotech Niagara Beta Awards in Buffalo, New York, USA.

March 26: Ithaca College EdTech Day in Ithaca, New York, USA.

March 27-29: PyCon in Chicago, Illinois, USA.

March 31-April 2: Linux Solutions in Paris, France.

April 1-2: OpenExpo in Bern, Switzerland.

Planet Fedora

In this section, we cover the highlights of Planet Fedora - an aggregation of blogs from Fedora contributors worldwide.

http://planet.fedoraproject.org

Contributing Writer: Adam Batkin

General

Rangeen Basu Roy Chowdhury explained how to build a Live USB stick from a Live CD image. Another option, suggested in the comments, is to use the liveusb-creator.

Paul W. Frields described some of the preparations that the Fedora Marketing team has been making for Fedora 11, including in-depth articles on some of the new features.

Richard Hughes showed off an updated Gnome PackageKit update viewer.

Rob Tiller, Vice President and Assistant General Counsel, IP at Red Hat responded to concerns within the community about Red Hat's patenting efforts and the Red Hat Patent Policy. Paul W. Frields wrote about the response, and a lively discussion in the comments ensued.

David Woodhouse posted about some documentation he had written to support Greylisting and the exim-greylist package shipped with Fedora.

Jef Spaleta wrote his "most important Fedora blog post ever" which revolves around the "NSF sponsored workshop on Sustainable Cyberinfrastructure". The workshop is important "for people who believe in either the function of basic science research as a catalyst for technical and social progress or people who believe strongly in open development methodologies as a catalyst for deeper and more impactful collaborations. Even more so if you happen to be in the union of those groups and a US citizen and care about how the NSF as a Federal agency goes about funding research and education."

As an interesting aside, Dave Jones mentioned that it takes two days and twenty minutes to run badblocks on his new 1TB hard drives.

Richard W.M. Jones worked on building a minimal Fedora installation and managed to get an installed system down to 225MB. He later responded to a comment about why it makes sense to minimize Fedora as opposed to building a custom minimal distribution. And then he managed to get the minimal distribution down to 15.9MB.

Amit Shah benchmarked various filesystems (including ext4) to find out how well they handled pre-allocation of disk space and the new Linux fallocate support.

Ambassadors

In this section, we cover Fedora Ambassadors Project.

http://fedoraproject.org/wiki/Ambassadors

Contributing Writer: Larry Cafiero

RIT Pitches in on OLPC Project

(This item corrects a report on this topic filed in FWN Number 166)

The Fedora OLPC project seems to have found a friend at Rochester Institute of Technology. Fedora Ambassador Karlie Robinson met RIT professor Stephen Jacobs at an OLPC Grassroots meeting on January 22 and learned of Jacobs' interest in doing a class around the XO.

Days later, David Nalley announced the Fedora Ambassador Developers Project and Karlie brought Professor Jacobs up to speed on what Fedora is doing around the XO, where Fedora is providing XOs to those who will do development work. The deal revolved around getting XOs for Jacobs classroom in exchange for the RIT students working on Greg DeKoenigsberg's 4th Grade Math project[1].

Got Ambassador News?

Any Ambassador news tips from around the Fedora community can be submitted to me by e-mailing lcafiero-AT-fedoraproject-DOT-org and I'd be glad to put it in this weekly report.

QualityAssurance

In this section, we cover the activities of the QA team.

Contributing Writer: Adam Williamson

Test Days

This week we had two test days, far more exciting than the boring regular one! The first was on DeviceKit, which will replace HAL for disk and power management in Fedora 11. Turnout was not the highest, but those who came along were able to find several issues which are being addressed with the help of some of the developers involved, including David Zeuthen and Matthias Clasen. The second test day was on Xfce, which is being updated to a major new release (4.6) in Fedora 11. A group of enthusiastic Xfce users showed up and were able to do some productive testing and refining of the Xfce environment together with the lead packager for Fedora, Kevin Fenzi.

Next week's test day will be on Nouveau, the new default video driver for NVIDIA cards for Fedora 11. This is a very important event, as NVIDIA graphics cards are the most popular type, and the new driver is a fairly big change, so we need testing on a wide range of hardware to make sure it's ready. A live CD will be available for the day so you'll be able to test without a Rawhide installation. It will be held on Thursday (2009-03-26) in the #fedora-qa channel on Freenode IRC. If you have an NVIDIA graphics card, please make sure to come along, or - if you can't make it on the day - do the tests and fill out your results on the page another day.

Weekly meetings

The QA group weekly meeting was held on 2009-03-18. The full log is available. James Laska reported good progress in his work on the Semantic test result reporting extension for mediawiki. Packaging is complete and he is next planning to put up a test instance of mediawiki with the plugin enabled.

Adam Williamson reported that the Intel graphics adapter test day had been a success, and a follow-up event was in the works. He also reported that a Radeon test day had not yet been planned and promised to follow that up with the appropriate developers.

Jesse Keating was asked to report on the status of the beta release. He said that current Rawhide and particularly Anaconda was still too unstable and said he expected the beta release would slip if he could not get a Rawhide tree with a good Anaconda soon. He requested further testing of Rawhide installation from the QA group, and some help from the main QA group and the Bugzappers group on organizing and checking existing bug reports against Anaconda.

Adam Williamson reported that the Xfce test day was fully planned, and Kevin Fenzi reported that he had successfully generated some live CD images for the test day. Adam asked if someone could make sure these images would be available for download.

The Bugzappers group weekly meeting was held on 2009-03-17. The full log is available. John Poelstra asked for feedback on the draft Standard Operating Procedure for new memberships which he had sent to the mailing list. The group generally approved of the draft. It was also agreed that the 'triagers' and 'fedorabugs' groups in FAS should be merged or linked, so that anyone who joined the triagers group automatically becomes a member of fedorabugs. Edward Kirk proposed not putting the SOP online and into operation until the appropriate changes have been made in FAS, and this was agreed. Christopher said he will send a draft of the new 'How to Triage' page to the mailing list for discussion in the coming week.

The group discussed Adam Williamson's draft front page for the Wiki area. Discussion centred on the links in the Tools and Procedures section. Adam explained that he expected further work on the Wiki to clean up and merge the pages linked to in that section, so the number of links would be smaller. Christopher Beland fixed the links in the draft which were broken. Christopher proposed putting up the new page immediately and then working to clean up the pages further down the hierarchy, and this was agreed by the group.

The group discussed the revised Components and Triagers wiki page and agreed the new layout was good. John Poelstra did not like the static statistics. Adam Williamson pointed out that it is planned to replace them with dynamically updated data from Brennan Ashton's metrics tool once it is complete.

John Poelstra brought up the potential meeting time and date change. Adam Williamson promised to send a mail to the mailing list summarising the results of the matrix survey to see if a definite conclusion could be made about whether to move the meeting.

The next QA weekly meeting will be held on 2009-03-25 at 1700 UTC (note changed time, in UTC reference frame) in #fedora-meeting, and the next Bugzappers weekly meeting on 2009-03-18 at 1500 UTC in #fedora-meeting.

Wiki changes

Adam Williamson announced that he had added a new column to the Components and Triagers wiki page to make it easy to find out who is the maintainer of a given component (and other information on it). Christopher Beland changed the stock response text for EOL bugs in an attempt to make it friendlier. Adam pointed out that changes to the stock responses should be mirrored in the GreaseMonkey script. Chris also announced a draft of a new How to Triage page for the group's feedback. Adam and Milos Jakubicek both approved of Chris' work and provided some suggestions to improve it.

Bugzilla status, priority and severity procedures

Christopher Beland began a discussion about the use of various statuses, resolutions and the priority and severity fields in Bugzilla. Adam Williamson pointed out that some of the more unconventional statuses and resolutions come from the RHEL side, where there is a specific and carefully defined workflow, and these statuses do not always mean exactly what they might appear to. Further to this, Tom Lane noted that the Bugzilla page defining each status contains accurate information on the RHEL workflow. He then suggested that a similar page should be created to define a standard workflow for Fedora bugs, and included in Bugzilla. Jesse Keating suggested that instead, the Fedora and RHEL workflows should be merged so that both would use the same statuses and resolutions in the same ways.

Developments

In this section the people, personalities and debates on the @fedora-devel mailing list are summarized.

Contributing Writer: Oisin Feeley

Auto Upgrading YUM Not Worth It

A discussion over the possible ways to upgrade from Fedora 10 to Fedora 11 was started by Gerry Reno when he asked why preupgrade from Fedora 10 only presented Rawhide as an option and not Fedora 11 Alpha.

A quick answer posted by Gianluca Sforna mentioned the technical difficulties of tracking the versions of packages included in the alpha release. Paul W. Frields was concerned that anyone trying such an upgrade made sure to update rpm before upgrading. This latter point spawned a longish thread in which the possibility of making YUM take care of checking to see whether a newer version of itself or rpm is available.

Will Woods suggested that running preupgrade instead of doing a `yum upgrade' avoided all that confusion.

How to Update from Fedora 10 to Rawhide

When "nodata" reported that an attempt to update rpm resulted in errors and preupgrade also failed he concluded that the instructions on the wiki were flawed.

Seth Vidal and Jesse Keating were sure that "nodata" was not using the correct procedure which they stated as a two stage process with the first step being a:

yum update rpm

with the Fedora 10 repository enabled and then to enable the Rawhide repository and do a general:

yum update

Unfortunately this seemed to not work for "nodata" and Michael A. Young's suggestion that a "[...] temporary issue with F10 having a more recent version of audit-libs than rawhide [...]" seemed like a promising lead. "Nodata" resolved problem by using the rescue CD to do a "rpm -e --nodeps" and then "rpm --rebuilddb".

Fedora 11 Beta Slips by One Week

Jesse Keating announced that Release Engineering, QA and maintainers had agreed that the beta release of Fedora 11 would slip by seven days due to several issues mostly related to the rewrite of anaconda storage.

Finding the Source

A request was posted for help in finding the Fedora kernel sources by Joe Ovanesian. A quick pointer was given by Tom Diehl:

# yum install yum-utils

# yumdownloader --source package_name

Eric Sandeen wondered if it might be better to use the upstream repositories and Joe explained that his objective was to build a new kernel from source and use KGDB to gain familiarity with the source. Todd Zullinger pointed to a goldmine of information on the topic on the wiki.

Fedorahosted Releases

Jon Stanley posted a quick note to say that he had made it easier to specify the upstream source URL in specfiles due to a change in fedorahosted.org

How to Open ACLs and Find Non-responsive Maintainers

A couple of related threads dealt with the need to deal with a package which lay dormant apparently due to maintainer inactivity.

Manuel Wolfshant had inquired earlier in the week about the allowing the provenpackagers to fix the gdal package. Jon Stanley promised to re-add a ticket dealing with the issue to an upcoming FESCo meeting.

In a separate thread the latest Rawhide Report led Kevin Kofler to ask for an opening of the ACLs on gdal so that it could be fixed for multiple dependent packages. When Jesse Keating asked Alex Lancaster if he started the non-responsive maintainer process the answer appeared to be that it was Jesse himself. In an aside MilosJakubicek provided links to the current process. Alex seemed to demonstrate clearly that the maintainer was inactive.

Translation

This section covers the news surrounding the Fedora Translation (L10n) Project.

http://fedoraproject.org/wiki/L10N

Contributing Writer: Runa Bhattacharjee

Upgraded Transifex

The backend for the statistics and submission page of FLP - translate.fedoraproject.org, has been migrated to the new version of Transifex. Submission of translations would continue via the new Transifex instance. Additionally, generation of translations statistics would also be done by this tool. All the modules from the damned-lies instance, used to generate statistics earlier, are now part of the transifex instance.

The new translate.fedoraproject.org page also allows translators to put temporary locks on files that they are currently translating. Bugs about the FLP transifex instance can be filed in the Red Hat bugzilla (Fedora-L10n/Transifex component) and bugs about Transifex are to be reported in the upstream Transifex trac.

New Coordinators/Members in FLP

Steven Whitehouse joined the FLP to start the Cornish language translation team. Kris Thomsen is the new Danish team coordinator.

Infrastructure

This section contains the discussion happening on the fedora-infrastructure-list

http://fedoraproject.org/wiki/Infrastructure

Contributing Writer: Huzaifa Sidhpurwala

svn-to-git Mirror

Jim Meyering said that he would like to set up an svn-to-git mirror for a project on fedorahosted. The mirror was set up and will be maintained by him at the Red Hat Emerging Technology Group webspace. It is not open for ssh access to people outside of Red Hat, so it's rather limited.

Change Requests

Due to the impending release of Fedora 11 beta, the infrastructure team is in a change freeze right now.

The following change requests were made during the week:

1. Change a piece of code in fas2 which would reduce a particular loop time from 5 mins to 8 seconds. This change was approved and the hotfix was put on the server.

2. Add redirect from /legal/trademarks/guidelines to http://fedoraproject.org/wiki/Legal:Trademark_guidelines. This change was approved.

3. Make transifex run under transifex user and not apache user. This change was also approved and committed.

4. Change request to update transifex on app1 to the 0.5 version. The change was approved.

5. Remove Fedora8 from the infofeed updates: Somehow fedora8 is still being looked for for the infofeed rss feed on planet.fedoraproject.org. This was approved and changes were made.

6. Use single quotes for the mysql backup cronjob,this has been causing us to get extra cron spam (and stalling mysql updates). Again this change was approved and committed.

7. Make sure inactive accounts can't auth to other webapps. Approved and committed.

8. Minor bodhi update. Changes include. Again approved and applied.

Artwork

In this section, we cover the Fedora Artwork Project.

http://fedoraproject.org/wiki/Artwork

Contributing Writer: Nicu Buculei

Post-inclusion Feedback for the Beta Artwork

After the new wallpaper design was included in Rawhide and presented to the users, the feedback process started.Jef Spaleta forwarded a concern raised on the OLPC list by Mikus Grinbergs, about the religious implications of using a temple "Seems to me whoever chose the background that was introduced last week did not consider that items with overtones of dissentious subjects such as politics or religion might elicit emotional reactions. I'm concerned that when my system prominently shows a picture with a temple, that might be interpreted as 'Mikus worships paganism'."

Martin Sourada did not support this reaction: "I don't see a valid reasoning there. There is vast difference between you worshiping ancient Greece gods (not that it would be something bad if you actually do) and having a huge Zeus' temple wallpaper hanging on your wall, let alone the wallpaper in your PC." Paul Frields explained "the conveyance as far as I know is simply to acknowledge the heritage of the 'Leonidas' name. Any other inference is probably a stretch" and Brian Hurren also supported this line of reasoning: "I think that the modern meaning of a Zeus temple is a lot broader now than it was before. Kind of like an old abbey in England would have a different meaning now." The conversation was spiced by a very sarcastic reaction from Máirí­n Duffy "I'm just too distraught to carry on. I feel like my entire world is full of these things symbolizing other things, and I'm finding myself strangely offended by everything."

Matthias Clasen raised another kind of criticism regarding the composition: "IMO it is really overloaded with all too well-known motifs, to the extent that it appears almost like a satire of a constructed background image. I mean, it has clouds and mountains and doves and a black forest and a green lawn _and_ a greek temple. Any 2 out of these 6 might combine to a nice background, but all six are just too much for my taste", a kind of positive feedback appreciated by Máirí­n as the purpose of releasing the graphic concepts early "Thank you for the feedback. Receiving this kind of feedback is exactly why we aimed to get a wallpaper into the beta."

A Possible New Direction for the Wallpaper

Considering the received feedback Máirí­n Duffy, raised the idea of a possible change of direction and going with a different theme, islands "I saw the movie Mama Mia this weekend for the first time, and it's a movie based on a pretty Greek island" or Mount Olympus "we could take the temple out of the current wallpaper and focus a bit more wholly on the mountains as the symbol of Greece rather than the temple", with Martin Sourada supporting a simplification of the 'temple' image "Hm... I'd say get rid of the trees or make them just complimentary part of the wallpaper, drop the focus away from mountains and instead have it on the temple" and Nicu Buculei whising more time to gather post-beta feedback "possibly this will make Paul nervous and it may put some deadlines in danger, but before committing to a radical change, I think it would be useful to see the post-beta feedback from a larger mass the users: the first wave of reviews, blogs and forum talks (the perception setters). We all here, supporters or critics, are pretty much subjectively involved and I think a breath of fresh air from the outside is valuable."

Completing all the Graphic Pieces

Máirí­n Duffy posted on @fedora-art a template proposal for various banners which would be used in Fedora 11 "What do you think about this as a base style to go with for the various banners/splashes for F11?" and asked the team for opinions about the Greek cultural motifs "Is it too over-the-top Greek? I was trying to go for a subtle and contemporary interpretation of a classic Greek motif." Charles Brej was enthusiastic and started working on a Plymouth theme based on it "I do like. Simple yet styled. I made a plymouth splash based on it" and Nicu Buculei proposed combining with the wallpaper image "I would like them more vivid, maybe combined with the photo we are going to use as a background?" a proposal took and improved Máirí­n, in what Paul Frields calls "art volleys".

Security Advisories

In this section, we cover Security Advisories from fedora-package-announce.

https://www.redhat.com/mailman/listinfo/fedora-package-announce

Contributing Writer: David Nalley

Fedora 10 Security Advisories

• mldonkey-3.0.0-1.fc10 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00617.html
• evolution-data-server-2.24.5-4.fc10 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00666.html
• opensc-0.11.7-1.fc10 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00673.html
• bugzilla-3.2.2-2.fc10 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00687.html
• ejabberd-2.0.4-1.fc10 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00735.html
• drupal-cck-6.x.2.2-1.fc10 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00757.html
• weechat-0.2.6.1-1.fc10 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00763.html
• thunderbird-2.0.0.21-1.fc10 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00769.html
• ghostscript-8.63-5.fc10 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00772.html

Fedora 9 Security Advisories

• mldonkey-3.0.0-1.fc9 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00542.html
• wireshark-1.0.6-1.fc9 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00652.html
• bugzilla-3.2.2-2.fc9 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00664.html
• evolution-data-server-2.22.3-3.fc9 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00672.html
• ejabberd-2.0.4-1.fc9 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00675.html
• opensc-0.11.7-1.fc9 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00686.html
• weechat-0.2.6.1-1.fc9 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00750.html
• drupal-cck-6.x.2.2-1.fc9 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00758.html
• ghostscript-8.63-2.fc9 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00770.html
• thunderbird-2.0.0.21-1.fc9 - https://www.redhat.com/archives/fedora-package-announce/2009-March/msg00771.html

Virtualization

In this section, we cover discussion on the @et-mgmnt-tools-list, @fedora-xen-list, @libvirt-list and @ovirt-devel-list of Fedora virtualization technologies.

Contributing Writer: Dale Bewley

Enterprise Management Tools List

This section contains the discussion happening on the et-mgmt-tools list

Virt-p2v and RAID Controller Drivers

Based on Fedora 10, "virt-p2v is an experimental live CD for migrating physical machines to virtual machine guests."

Jonathan Pregler and Nick Haunold asked about a lack of HP and Dell RAID drivers in virt-p2v. No answer was found, but Jonathan Pregler is now working on creating a SUSE live CD with virt-p2v and the RAID drivers embedded.

NetWare Support added to virtinst

John Levon patched python-virtinst to support NetWare PV installs.

Fedora Xen List

This section contains the discussion happening on the fedora-xen list.

Which Xen Configuration Files

Urs Golla was confused "about the configuration files for XEN user domains in Fedora."

Daniel P. Berrange explained that parts of Xen uses different configuration formats.

• xend stores master config files in SXPR format in /var/lib/xend.
• xm stores python-like config files in /etc/xen

"XenD itself has no knowledge of these files," (in /etc/xen) "so it can't manage them. They should not be used in Xen >= 3.0.4 If you have existing files in /etc/xen, then you can load them into XenD by doing 'xm new configname', at which point both Xend and libvirt will be able to manage them. For Xen < 3.0.4 libvirt has some limited support for reading /etc/xen files directly"

Using libvirt and the virsh command, the above configuration files are essentially obviated. Instead an intermediate XML configuration can be modified and applied back to xend.

Libvirt List

This section contains the discussion happening on the libvir-list.

Xen PCI Device Passthrough

A patch from Daniel P. Berrange "provides initial support for PCI device passthrough in Xen, at time of boot. It does not (yet) implement device hotplug for PCI". "XenD only supports 'unmanaged' PCI devices - ie mgmt app is responsible for detaching/reattaching PCI devices from/to host device drivers. XenD itself won't automatically do this".

Secure Guest Migration Draft Patch

Chris Lalancette followed the RFC of last week with a "rough first draft of the secure migration code" and sought comments on the approach before putting the final polish on it.

Daniel Veillard wasn't enitrely satisfied with the "costs related to the 64KB chunking imposed by the XML-RPC" and was "Trying to reopen a bit the discussion we had before on opening a separate encrypted connection". Daniel Veillard "would like to make sure we have room in the initial phase to add such a negociation where an optimal solution" on a dedicated TCP/IP connection "may be attempted, possibly falling back to a normal XML-RPC solution".

Daniel P. Berrange pointed out "This isn't XML-RPC. This is our own binary protocol using XDR encoding, which has very little metadata overhead - just a single 24 byte header per 64kb of data.", and poposed a 'MIGRATION_INCOMING' message which could cause libvirted to "switch the TCP channel to 'data stream' mode."

Chris Lalancette tested the migration code and found the draft secure migration caused a "slowdown of between 1.5 and 3 times". "What I'm going to do early next week is do some additional work to try to get DanB's suggestion of the STREAM_DATA RPC working. Then I'll try benchmarking (both for duration, and CPU usage)".

More Flexible x86 Emulator Choice

Daniel P. Berrange explained the current libvirt restricts "what emulator binary we allow for QEMU guests on x86 arches". "This patch makes QEMU driver more flexible" ... "when setting up its capabilities information." "This should finally remove the confusion where a user in virt-manager selectrs 'i686' and then wonders why we've disallowed choice of 'kvm'. It also fixes 'virsh version' when only qemu-kvm is installed."

The path to each emulator binary is hardcoded in libvirt. Daniel Veillard found this approach "worrying". The merge of qemu and kvm will make the reliance on a pathname to determine a binary's capabilities even less tenable.

Daniel P. Berrange agreed "this approach we're currently using has pretty much reached the end of its practicality. In particular it is impossible to solve the problem of figuring out whether a plain 'qemu' binary supports kvm natively. To adress that, we'd actually need to run the binary and probe its output. This would require pretty much re-writing this entire capabilities setup logic from scratch. Similarly coping with varying path locations is another problem we can't easily solve with this current code."