[Pkg-xen-devel] libxen-dev, libxen-4.8: Potential upgrade path issues with regard to qemu

[Stephen Oberholtzer]

While attempting to troubleshoot a problem with PCI passthrough, I noticed
a number of facts that, when considered together, may indicate a serious
upgrade path issue with regard to Xen and QEMU:

1. libxen-dev is a single package with two versions: a 4.8 version and a
4.11 version
2. libxen-dev version 4.8 produces libraries with 4.8 in the soname.  A
qemu compiled against this version has Depends: libxen-4.8
3. libxen-dev version 4.11 produces libraries with no version number in the
soname (except those in libxenmisc).  A qemu compiled against this version
has Depends: libxendevicemodel1,  libxenevtchn1,  libxenforeignmemory1,
libxengnttab1, libxenmisc4.11

There doesn't seem to be a way by which qemu could be packaged to work with
*either* 4.8 or 4.11:
If you have a qemu that was compiled against libxen-dev=4.8, your qemu will
*only* use the libxen-4.8 files.
If you have a qemu that was compiled against libxen-dev=4.11, your qemu
will use the latest version of 4.11-style-packaged libraries, except for
libxenctrl and libxenguest, which will always use 4.11.

I understand that dealing with this is at least partially the
responsibility of the Debian QEMU Team, which is why I've CC'd them.
However, this seems to suggest that qemu packaging would need to be updated
in lockstep with Xen, even if someone is using qemu in kvm or standalone
mode!

-- 
-- Stevie-O
Real programmers use COPY CON PROGRAM.EXE
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://alioth-lists.debian.net/pipermail/pkg-xen-devel/attachments/20181013/06e57222/attachment.html>