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. > @@ -647,6 +647,8 @@ struct task_struct fastcall * __switch_t > */ > savesegment(fs, prev->fs); > savesegment(gs, prev->gs); > + clearsegment(fs); > + clearsegment(gs); > Really not needed. Think about it. You can even speed up Xen. I'm glad the native operation here is a nop, but it should be hypervisor_clearsegment or xen_clearsegment if you really want to keep it. Zach
