Messages in this thread |  | | Date | Mon, 27 Nov 2017 14:18:44 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [patch V2 1/5] x86/kaiser: Respect disabled CPU features |
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On Mon, 27 Nov 2017, Brian Gerst wrote: > On Mon, Nov 27, 2017 at 6:47 AM, Thomas Gleixner <tglx@linutronix.de> wrote: > > On Mon, 27 Nov 2017, Peter Zijlstra wrote: > >> On Mon, Nov 27, 2017 at 12:14:04AM +0100, Thomas Gleixner wrote: > >> > PAGE_NX and PAGE_GLOBAL might be not supported or disabled on the command > >> > line, but KAISER sets them unconditionally. > >> > >> So KAISER is x86_64 only, right? AFAIK there is no x86_64 without NX > >> support. So would it not make sense to mandate NX for KAISER?, that is > >> instead of making "noexec" + KAISER work, make "noexec" kill KAISER + > >> emit a warning. > > > > OTOH, disabling NX is a simple way to verify that DEBUG_WX works correctly > > also on the shadow maps. > > > > But surely we can drop the PAGE_GLOBAL thing, as all 64bit systems have it. > > I seem to recall that some virtualized environments (maybe Xen?) don't > support global pages.
Uuurg. Ok, we leave it as is for now. Better safe than sorry. It does no harm.
Thanks,
tglx
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