On Tue, 2013-02-12 at 10:34 +0000, Ian Campbell wrote:
On Mon, 2013-02-11 at 17:28 +0000, David Woodhouse wrote:
I take it the first step is running 'yum install xen' on my Fedora workstation, and rebooting into Xen with the Fedora kernel as Dom0?
I was going to say no, you need to build from source if you want to experiment with different SeaBIOS versions, but actually that isn't quite true -- you can install from packages and then use the packaged source to rebuild hvmloader against the newer SeaBIOS. This is a path less trodden but I guess might be simpler for you? You'll need a version of Fedora which includes Xen 4.2, since that is where seabios became an option, I expect this means Fedora 18+ is required.
Yes, anything below Fedora 18 ships Xen 4.1.something.
I've CC'd Dario who is the Fedora user on our team, since I'm a Debian type myself and generally build Xen from source anyhow I'm not 100% confident in some of the bits below which may be tweaked by distros.
Here I am. :-)
For docs you can find a few bits about Xen on Fedora at http://wiki.xen.org/wiki/Category:Fedora especially http://wiki.xen.org/wiki/Fedora_Host_Installation but basic install is as you suggest "yum install xen" and reboot (but see the wiki for stuff on how to tame network manager etc, if you haven't already for other reasons).
Yes, please, have a look at those pages and feel free to let me know if you find anything unclear or wrong! Also, I refactored the Fedora_Host_Installation page quite a bit this morning, so check it out again, even if you've been there before.
At this point you'll want to create a guest, I don't think you actually need a fully functioning one to test SeaBIOS. I suppose the Fedora way to do this would be to use virt-install or virt-manager or something (perhaps Dario can advise), but I'd be tempted to just use the xen command line tools.
Well, that depends on what you install. After an `yum install xen' + reboot, you don't have any libvirt related package installed, and you can go ahead using xl, as Ian describes.
Xend is not started automatically on boot so, again, xl is what is most suitable in this situation.
That being said, if you go on and install the various libvirt-* packages, as suggested in that page, virt-manager and virt-install will become options, but (due to some bug we're chasing but haven't fixed yet in Fedora), that will cause xend to run, which, on its turn, will make using xl impossible.
So, what toolstack you want to use, is indeed up to you. I'm not familiar with SeaBIOS and with the kind of tests you want to run but, from what I understand reading the rest of this e-mail, I also recommend just stopping after `yum install xen' and using xl _instead_ of libvirt.
There are two toolstacks in Xen today but only the new "xl" toolstack supports using SeaBIOS, the deprecated xend toolstack doesn't have this option. I'm afraid I've no idea which Fedora 18 defaults to (I hope this is something Dario can clarify), if it is xend then you will need to chkconfig xend off and perhaps reboot. If xend is running then xl will complain.
Well, I guess we can say that, as far as only Xen is installed, since xend is not started, the default toolstack is actually xl on Fedora too.
First create a guest configuration file (seabios.cfg) with the following: builder = "hvm" name = "seabios" device_model_version_override = "qemu-xen" memory = 512 serial = 'pty'
This doesn't include any disks or nics, but should boot enough to test basic seabios up until the "no bootable device" message. A nic is easy to add: vif = [''] will create one with a random mac, add mac=xx:xx:xx:xx:xx inside the '' if you want something specific.
In which case I think (if you want the NIC to work) you need to configure a bridge. The Fedora_Host_Installation wiki page should have all the info you need wrt this.
If there is anything you think I can be of more help with, please, do not hesitate to ask. :-)
Regards, Dario