On Sat, Feb 01, 2014 at 08:07:07PM +0000, Manuel Bouyer wrote: > Module Name: src > Committed By: bouyer > Date: Sat Feb 1 20:07:07 UTC 2014 > > Modified Files: > src/sys/arch/xen/xen: hypervisor.c > > Log Message: > Revert previous: calling fpuinit() leads to a panic, as a domU is not > allowed to manipulate cr0 directly. Xen doesn't need this, the fpu is > handled by the hypervisor.
I probably remember seeing that panic as well. XEN might need the bits of fpuinit() that don't play with cr0. In particular a fninit and setting TS. Although I'm not 100% sure the TS is needed on a single cpu system. It isn't there on amd64, but really it does no harm. Without it one process will have an indererminate fp state. I can't say I've actuallly looked a xen. Presumably we somewhere compile the hypervisor as part of a kernel? David -- David Laight: da...@l8s.co.uk