[Pkg-xen-devel] Bug#668641: Please add a symlink /usr/lib/xen -> /usr/lib/xen-default
thomas at goirand.fr
Sun Apr 15 19:15:42 UTC 2012
Thanks for your time replying.
On 04/16/2012 01:51 AM, Bastian Blank wrote:
> On Sun, Apr 15, 2012 at 04:43:06AM +0800, Thomas Goirand wrote:
>> When designing a software for Xen, we don't want to have to handle a
>> specific case for Debian, where /usr/lib/xen is called another way. We
>> don't want either to have to patch some upstream code that may be using
>> /usr/lib/xen if we want to package it in Debian.
> /usr/lib/xen does not describe a public interface.
>> Having /usr/lib/xen being the currently running hypervisor is what we
>> want here (eg: we might need it at runtime, I don't see any cases where
>> we would need it at build time, but I might be wrong).
> This is not possible. /usr have to be considered read-only.
The only thing we need to fix the situation is:
ln -s xen-default /usr/lib/xen
and that's it! No need to write things in /usr. This is a one-line fix
in your packaging!
>> For example, someone might want to access things under /usr/lib/xen/bin,
>> or the hvmloader.
> hvmloader and other stuff in the configs should be addressed with
> relative paths.
Could you explain this a bit more? Do you mean that, in a domU startup
file, we should just write:
kernel = "hvmloader"
without the full path? Does this work as well with pygrub? Can I write:
bootloader = "pygrub"
My understanding was that we are currently forced into writing:
bootloader = '/usr/lib/xen-default/bin/pygrub'
which is Debian specific... Am I wrong?
>> Or libxenlight.so
> libxenlight.so needs to be the exact match, it does not include an
>> (which is a public API that isn't in
>> /usr/lib, so it might need a RPATH, which here is specific to Debian).
> Stuff outside of the normal library search path is not public. So
> libxenlight is not a public interface in Debian.
My understanding is that, at least when Xen 4.2 will be out, libxl will
be considered a public interface. Ian Campbell wrote in xen-devel:
"we would like [Xen] 4.2 to define a stable API which downstream's can
start to rely on not changing."
So if currently you may be right, Xen is taking the direction to have
libxl as a public interface. Maybe Debian should ship libxenlight.so in
the search path and have it with ABI versions... Or do you think this
shouldn't happen before Xen 4.2? Thoughts?
More information about the Pkg-xen-devel