There is a FOSS Factory bounty (p274) on this task.

There are now specialized variants of Debian's libc package, libc0.3-i686 and libc0.3-xen.

On Thu, Oct 07, 2010 at 11:22:46AM +0200, Samuel Thibault wrote:

Thomas Schwinge, le Thu 07 Oct 2010 10:11:07 +0200, a écrit :

Also, this text says ``will be selected instead when running under Xen'' -- is this meant to be automatically done?

It's supposed to be, we need to add support for it.

If so, then it didn't work.

Yes, you need to copy it by hand. Same for libc0.3-i686, we just need to steal the cpuid code from the kfreebsd port of glibc.

Having working CPUID code inside glibc is also a prerequisite for proper IFUNC support.