* Zachary Amsden (zach@xxxxxxxxxx) wrote: > 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. Please describe how. I'm afraid I'm missing your point, as I don't see the improvement. > 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. Yeah, Andi had similar naming concern.
