From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 02E2E6B0069 for ; Tue, 31 Oct 2017 21:08:36 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id p87so680561pfj.21 for ; Tue, 31 Oct 2017 18:08:35 -0700 (PDT) Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTPS id p66si2749399pga.805.2017.10.31.18.08.34 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 31 Oct 2017 18:08:34 -0700 (PDT) Subject: Re: [PATCH 01/23] x86, kaiser: prepare assembly for entry/exit CR3 switching References: <20171031223146.6B47C861@viggo.jf.intel.com> <20171031223148.5334003A@viggo.jf.intel.com> From: Dave Hansen Message-ID: Date: Tue, 31 Oct 2017 18:08:33 -0700 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Brian Gerst Cc: Linux Kernel Mailing List , Linux-MM , moritz.lipp@iaik.tugraz.at, daniel.gruss@iaik.tugraz.at, michael.schwarz@iaik.tugraz.at, Andy Lutomirski , Linus Torvalds , Kees Cook , hughd@google.com, the arch/x86 maintainers On 10/31/2017 05:43 PM, Brian Gerst wrote: >> >> + RESTORE_CR3 save_reg=%r14 >> + >> testl %ebx, %ebx /* swapgs needed? */ >> jnz nmi_restore >> nmi_swapgs: >> _ > This all needs to be conditional on a config option. Something with > this amount of performance impact needs to be 100% optional. The 07/23 patch does just this. I should have at least called that out in the description. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org