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=-0.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 2B3D9C433DF for ; Tue, 23 Jun 2020 16:14:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F230A2076E for ; Tue, 23 Jun 2020 16:14:13 +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="ATjsWIR5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732662AbgFWQOM (ORCPT ); Tue, 23 Jun 2020 12:14:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732253AbgFWQOM (ORCPT ); Tue, 23 Jun 2020 12:14:12 -0400 Received: from merlin.infradead.org (unknown [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0B63FC061573; Tue, 23 Jun 2020 09:14:12 -0700 (PDT) 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; bh=2ZeuviZXPtyZ/aF+IWZIvBCFWEao8ngk72TsRFpdUlQ=; b=ATjsWIR5mScsdXgmjIWTkFg1Wk j3PvAh/3jFwmTPn+cKufy4YfwEAVTB5Q+YDKJxIFA/YBf8QnuKGZB6iBvijGNLqsyu010C+STY8WW LAB3d9puouEtlsYWgQtJ+x3DVKMIoh/RG/cNY63fcTwbR+z6FfaHoyxaXbpm9V+Gsr6kNlqXZaL0H Ea0iQWyFLSV4klNOb2ksXlD1PlNyImPPRPhFq5Tv2I6Q3BeNur0uGK7mHwgDTiWh9oUuj3yijj6Sy VY7TJOMc0JboU8lVaX9JX8xVVicMeVSgx92/mx8HMv+xWWnNs0kZMIoGwIGEnFy0KFzU+Hif8FPzi gviDAAUA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jnlYR-0006db-JS; Tue, 23 Jun 2020 16:13:47 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id D6622306E5C; Tue, 23 Jun 2020 18:13:45 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id C4847234EBA51; Tue, 23 Jun 2020 18:13:45 +0200 (CEST) Date: Tue, 23 Jun 2020 18:13:45 +0200 From: Peter Zijlstra To: Dave Hansen Cc: Andrew Cooper , Joerg Roedel , Andy Lutomirski , Joerg Roedel , Tom Lendacky , Mike Stunes , Dan Williams , Dave Hansen , "H. Peter Anvin" , Juergen Gross , Jiri Slaby , Kees Cook , kvm list , LKML , Thomas Hellstrom , Linux Virtualization , X86 ML , Sean Christopherson Subject: Re: Should SEV-ES #VC use IST? (Re: [PATCH] Allow RDTSC and RDTSCP from userspace) Message-ID: <20200623161345.GQ4817@hirez.programming.kicks-ass.net> References: <20200623120433.GB14101@suse.de> <20200623125201.GG4817@hirez.programming.kicks-ass.net> <20200623134003.GD14101@suse.de> <20200623135916.GI4817@hirez.programming.kicks-ass.net> <20200623145344.GA117543@hirez.programming.kicks-ass.net> <20200623145914.GF14101@suse.de> <20200623152326.GL4817@hirez.programming.kicks-ass.net> <56af2f70-a1c6-aa64-006e-23f2f3880887@citrix.com> <20200623155204.GO4817@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 23, 2020 at 09:03:56AM -0700, Dave Hansen wrote: > On 6/23/20 8:52 AM, Peter Zijlstra wrote: > > Isn't current #MC unconditionally fatal from kernel? But yes, I was > > sorta aware people want that changed. > > Not unconditionally. copy_to_iter_mcsafe() is a good example of one > thing we _can_ handle. Urgh, I thought that stuff was still pending. Anyway, the important thing is that it is fatal if we hit early NMI. Which I think still holds. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: Should SEV-ES #VC use IST? (Re: [PATCH] Allow RDTSC and RDTSCP from userspace) Date: Tue, 23 Jun 2020 18:13:45 +0200 Message-ID: <20200623161345.GQ4817@hirez.programming.kicks-ass.net> References: <20200623120433.GB14101@suse.de> <20200623125201.GG4817@hirez.programming.kicks-ass.net> <20200623134003.GD14101@suse.de> <20200623135916.GI4817@hirez.programming.kicks-ass.net> <20200623145344.GA117543@hirez.programming.kicks-ass.net> <20200623145914.GF14101@suse.de> <20200623152326.GL4817@hirez.programming.kicks-ass.net> <56af2f70-a1c6-aa64-006e-23f2f3880887@citrix.com> <20200623155204.GO4817@hirez.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" To: Dave Hansen Cc: Juergen Gross , Tom Lendacky , Thomas Hellstrom , Joerg Roedel , Mike Stunes , Kees Cook , kvm list , Andrew Cooper , Joerg Roedel , Dave Hansen , LKML , Sean Christopherson , Linux Virtualization , Andy Lutomirski , "H. Peter Anvin" , Dan Williams , Jiri Slaby , X86 ML List-Id: virtualization@lists.linuxfoundation.org On Tue, Jun 23, 2020 at 09:03:56AM -0700, Dave Hansen wrote: > On 6/23/20 8:52 AM, Peter Zijlstra wrote: > > Isn't current #MC unconditionally fatal from kernel? But yes, I was > > sorta aware people want that changed. > > Not unconditionally. copy_to_iter_mcsafe() is a good example of one > thing we _can_ handle. Urgh, I thought that stuff was still pending. Anyway, the important thing is that it is fatal if we hit early NMI. Which I think still holds.