[Pkg-xen-devel] Bug#649349: Bug#649349: xen-hypervisor-4.1-amd64: pygrub fails due to invalid opcode trapped

[Alexandre Vaissière]

Le 23/11/2011 15:08, Ian Campbell a écrit :
>>> If you boot the same kernel natively what happens when you run pygrub?
>>> (this should work natively, although obviously you won't be able to
>>> actually start a VM).
>> Yes it does work: I see the grub interface.
> What happens if you pass "noxsave" to the native kernel?
>
> [...]
> If I am right then using "noxsave" on native should demonstrate the
> issue as well and show that there is a bug in libc.
>
you are right. With noxsave, I have same behaviour of pygrub under a
native kernel.
> However that doesn't rule out a bug in the hypervisor as well since it
> should support xsave... except I've just noticed that xsave is
> deliberately disabled in Xen 4.1!
>
> It has been re-enabled in xen-unstable with the comment "re-enable xsave
> by default now that it supports live migration" (so it will work in 4.2
> when it is released). This suggests that you could try with "xsave=1" on
> your hypervisor command line (but that migration won't work).
>
With xsave=1 pygrub works ! However xend segfaults later while starting
the domU :/
Will try to get a stack, but as you state below:

> Which seems to already be reported and fixed upstream:
> http://sourceware.org/bugzilla/show_bug.cgi?id=13007
> as well as against glibc in Debian http://bugs.debian.org/646549. The
> fix is fixed in glibc-package SVN so ought to be fixed with the next
> upload (2.13-22).
>
Maybe I should wait for this libc release before going further.

Alexandre.