Re: [Xen-devel] Different esps

[Jacob Gorm Hansen <jacob@xxxxxxxx>]

On Tue, 2004-01-20 at 19:24, Keir Fraser wrote:

> >     HYPERVISOR_set_trap_table(trap_table);
> >     HYPERVISOR_set_fast_trap(SYSCALL_VECTOR);
> 
> The alternative is to copy this info between the
> full_execution_context's of the old and new domains.

Except that with my setup I do not have access to these, unless there is
a way to map them from within each unprivileged domain.

> Looks weird. Why not instrument Xenolinux's trap handlers to see which
> exception you are occasionally taking. It's not hard -- most go thru
> do_trap() in arch/xeno/kernel/traps.c. GPFs and page faults go thru
> separate specialised functions.

It seems with a little more wiggling of things (especially installing
the trap vectors _before_ touching the ring1 stack of current) makes me
run quite a bit further, though not really far.

thanks,
Jacob