On Wed, 2016-06-29 at 11:34 +0100, Daniel P. Berrange wrote:
On Wed, Jun 29, 2016 at 12:15:02PM +0200, Florian Weimer wrote:
> On 06/29/2016 12:03 PM, Daniel P. Berrange wrote:
> > Debian handles this by having several packages 
> > - qemu-user - the dynamic linked qemu user binaries
> > - qemu-binfmt - binfmt rules registering the dynamic linked binaries
> > - qemu-user-static - the static linked qemu user binaries *and* binfmt
> > rules to register them. The static binaries all
> > have -static suffix on their name
> Debian builds static libraries and puts them into their -dev packages.
> Fedora does not do this systematically. Are all the static libraries you
> need actually available in Fedora?
Yes, everything we need exists - as mentioned its only glibc-static,
glib2-static, zlib-static and pcre-static that we need for this.
> An alternative would be to bind-mount the real file system into the chroot
> and run the native dynamic linker with a --library-path command line
> argument that specifies the library directories in the bind mount. (It's
> reasonable to specify --inhibit-cache as well.) This would need some
> adjustments in the binfmt wrapper.
The binfmt registrations are global to the OS, so the same binfmt command
needs to work whether inside or outside the chroot. So a scheme which
requires us to pass special args to make the linker looks elsewhere when
inside the chroot is not so easy. We'd have to create a wrapper program
around the real qemu user binary that decides which args to pass to the
linker, and that wrapper would then have to be statically linked
Just an idea:
Would it make sense to build the qemu-user binary so that it looks in a
different /lib directory (using rpath) like /lib/qemu-user-systemlib,
and then symlink into that directory the libraries it needs from the
That way if you use chroot and bind mount in that directory in the right
place the qemu-user binary uses different libraries from the emulated
binaries yet you do not have to resort to static linking.
Simo Sorce * Red Hat, Inc * New York