From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C51D4C742B9 for ; Fri, 12 Jul 2019 12:37:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 950B42080A for ; Fri, 12 Jul 2019 12:37:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="XWiPp5T3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729511AbfGLMhQ (ORCPT ); Fri, 12 Jul 2019 08:37:16 -0400 Received: from merlin.infradead.org ([205.233.59.134]:34172 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727762AbfGLMhQ (ORCPT ); Fri, 12 Jul 2019 08:37:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=PRvJtsiHkVhvqvxWg5gOuLt8FA07mI2n7b2F9lWVt6s=; b=XWiPp5T3wZ07wSFz7SP2NGQsi SARqMlSa4wSWOALaD9zIg48cd8FkwtQzlyIqn2H/VG3zk8ew8txJuiyK0bOkKModvW1URTSAtHINQ BZfWo+f5pIdJEIj7pAAvGEgTpPGjztlFq+c1d86X1AriCw0HX9pAgtl/T5P5ViqzB3YbIpgpshlHU P1J4uQYE12VLgjTpHpbC3L2N8BZKengJ4RvrWQRLvD4ZCTcLEujoFj57iE9i92rblgnnWe2dtnErg JISh4LW8iD+LzsB0jFgfRy48PCLVuwRGtiiYaxws8B1vrL+LnY4BgsRnlKs2MI4YxasxwKR7M1GTy hU+YmR/Kw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hlunH-0005Rb-23; Fri, 12 Jul 2019 12:36:56 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 65784209772E6; Fri, 12 Jul 2019 14:36:53 +0200 (CEST) Date: Fri, 12 Jul 2019 14:36:53 +0200 From: Peter Zijlstra To: Alexandre Chartre Cc: pbonzini@redhat.com, rkrcmar@redhat.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, kvm@vger.kernel.org, x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, konrad.wilk@oracle.com, jan.setjeeilers@oracle.com, liran.alon@oracle.com, jwadams@google.com, graf@amazon.de, rppt@linux.vnet.ibm.com, Paul Turner Subject: Re: [RFC v2 00/27] Kernel Address Space Isolation Message-ID: <20190712123653.GO3419@hirez.programming.kicks-ass.net> References: <1562855138-19507-1-git-send-email-alexandre.chartre@oracle.com> <20190712114458.GU3402@hirez.programming.kicks-ass.net> <1f97f1d9-d209-f2ab-406d-fac765006f91@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1f97f1d9-d209-f2ab-406d-fac765006f91@oracle.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Jul 12, 2019 at 02:17:20PM +0200, Alexandre Chartre wrote: > On 7/12/19 1:44 PM, Peter Zijlstra wrote: > > AFAIK3 this wants/needs to be combined with core-scheduling to be > > useful, but not a single mention of that is anywhere. > > No. This is actually an alternative to core-scheduling. Eventually, ASI > will kick all sibling hyperthreads when exiting isolation and it needs to > run with the full kernel page-table (note that's currently not in these > patches). > > So ASI can be seen as an optimization to disabling hyperthreading: instead > of just disabling hyperthreading you run with ASI, and when ASI can't preserve > isolation you will basically run with a single thread. You can't do that without much of the scheduler changes present in the core-scheduling patches.