Re: [RFC PATCH 17/35] Segment register changes for Xen

Zachary Amsden
2006-03-23T00:17:00Z

Chris Wright wrote:
> 1. We clear FS/GS before changing TLS entries and switching LDT, as
> otherwise the hypervisor will fail to restore thread-local values on
> return to the guest kernel and we take a slow exception path.
>

This should not be needed. You should clear FS/GS that match updated
descriptors in your descriptor validation code instead. And you will
get better performance for both native and the hypervisor cases.