>>> On 01.05.18 at 14:34, <boris.ostrov...@oracle.com> wrote: > On 05/01/2018 04:00 AM, Roger Pau Monné wrote: >> On Mon, Apr 30, 2018 at 12:23:39PM -0400, Boris Ostrovsky wrote: >>> And without it we can't use _BOOT_XX macros any longer so define new ones. >> >> Not being that familiar with Linux internals I'm not sure I see the >> benefit of this. Isn't there a risk that some other code is going to >> use the __BOOT_XX defines? > > The startup code we are jumping to loads their own GDT and I don't see > any explicit references to segments.
No explicit references to segments isn't enough: You also need to make sure no exceptions at all can occur while loaded selectors and GDT are out of sync - in particular NMI might be of concern here (this isn't PV after all, where not having a callback registered effectively masks NMI). Jan
