From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754498AbdKAOJQ (ORCPT ); Wed, 1 Nov 2017 10:09:16 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:49638 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751682AbdKAOJP (ORCPT ); Wed, 1 Nov 2017 10:09:15 -0400 Date: Wed, 1 Nov 2017 15:09:02 +0100 (CET) From: Thomas Gleixner To: Ingo Molnar cc: Dave Hansen , LKML , linux-mm@kvack.org, Andy Lutomirski , Linus Torvalds , Peter Zijlstra , "H. Peter Anvin" , borisBrian Gerst , Denys Vlasenko , Josh Poimboeuf , Thomas Garnier Subject: Re: [PATCH 00/23] KAISER: unmap most of the kernel from userspace page tables In-Reply-To: <20171101085424.cwvc4nrrdhvjc3su@gmail.com> Message-ID: References: <20171031223146.6B47C861@viggo.jf.intel.com> <20171101085424.cwvc4nrrdhvjc3su@gmail.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 1 Nov 2017, Ingo Molnar wrote: > Beyond the inevitable cavalcade of (solvable) problems that will pop up during > review, one major item I'd like to see addressed is runtime configurability: it > should be possible to switch between a CR3-flushing and a regular syscall and page > table model on the admin level, without restarting the kernel and apps. Distros > really, really don't want to double the number of kernel variants they have. And this removes the !PARAVIRT dependency as well because when the kernel detects xen_pv() then it simply disables kaiser and all works. Thanks, tglx