[Pkg-xen-devel] Xen 4.10 for Debian unstable

[John Keates]

> On 22 Feb 2018, at 01:42, Hans van Kranenburg <hans at knorrie.org> wrote:
> 
> Hi,
> 
> On 02/22/2018 01:03 AM, John Keates wrote:
>> 
>> First of all, thanks for the great work! I was wondering about a patch I tried to send in a while ago which enables OVMF. It’s a single line in the rules setup and doesn’t have any build-time or run-time dependencies until you actually change a domU configuration to use OVMF.
>> 
>> Currently I just rebuild all packages locally and add the line to debian/rules.real:
>> 
>> --enable-ovmf --with-system-ovmf=/usr/share/ovmf/OVMF.fd 
>> 
>> Is this something that could be added to 4.10?
> 
> I guess so.
> 
> Which packages are your rebuilding? The 4.8 ones or are you creating
> something based on the new 4.10 packages?
> 
> I can rtfm https://wiki.xenproject.org/wiki/OVMF but can you also
> provide some kind of recipe how to set up a tl;dr domU using this as a
> test case? If so, I can already test it myself already also.
> 
> For me, the most beautiful thing would be if you send a patch that
> applies on top of https://salsa.debian.org/xen-team/debian-xen master
> branch with a test report telling "it works \o/" (explaining what
> actually works) when running a build made from that (see README.source
> how to create a package).
> 
> It's just that there are so many things you can do with Xen, and I don't
> remotely want to give the impression I understand all of them. (I've
> been running Xen at work since 2006 but still discovering many new things).
> 
> Also, another logical question would be if you're willing to help
> handling future debian bug reports that are related to OVMF after we
> enable it. ;-)
> 
> Hans

I basically just do a apt-get source xen, then in the resulting xen-4.x.x-something-something directory I edit debian/rules.real and add the line to the existing list of configure options. (I think the list is in there twice)
Next I run debuild -us -uc and then dpkg -i ./*.deb to install (well, I skip the dbg/sym packages). I think I made a patch for it months ago, but I doubt it works on the current in-repo version or on 4.10 because it refers to line number 74 in rules.real which now contains something else at that line ;-)

To use, I install the existing ovmf package to provide the ovmf.fd file (this is also used by qemu / kvm etc.), and then configure a domu cfg with:

bios = “ovmf"
builder = ‘hvm'

When starting, instead of seeing SeaBIOS or ROMBIOS or some other emulated firmware, you get Tianocore/EFI. This allows you to run operating systems that require EFI. It probably has a ton of other features, for some reason I have to use it with some firewall operating systems to add more than 3 NICs, and some Windows server variants require it as well.

It doesn’t do much else by itself, OVMF is just ‘another’ bios option, there is no special configuration on the dom0 side (well, you need ovmf installed but that’s it). If you don’t specify bios=ovmf in any domU, it doesn’t actually come in to play at any point, which makes this a zero-side-effect addition. I can try getting on to Debian’s GitLab in a while, but for a single-line change (or double line change? Saw the configuration lines appear twice in rules.real now, one for debug one for normal?) this might be something simple enough to just enable.

John