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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 86423C3B187 for ; Tue, 11 Feb 2020 22:12:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5EE3620708 for ; Tue, 11 Feb 2020 22:12:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581459140; bh=yNqZod946paujAdEqMRJ1ejAWBjSCe4eeJhwXaauReA=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=BKuEj0mWXOju+j8x11/HxI/K+MQMXvcqSiqbRs5xP+ywioQQ7CwuoWSMzPl2Z+Zbq 11jsBmUXkifeoDXA1Q19RqlNTrCLPM3Uj4PtmDswsR/oAdjgHtX7//xCdpnzVXvKEu WlFpy/HiO9rfzNeZjpaNRCJ065jj5ryCvwndQXKg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727549AbgBKWMT (ORCPT ); Tue, 11 Feb 2020 17:12:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:48442 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727041AbgBKWMS (ORCPT ); Tue, 11 Feb 2020 17:12:18 -0500 Received: from mail-wr1-f41.google.com (mail-wr1-f41.google.com [209.85.221.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DFE7E20870 for ; Tue, 11 Feb 2020 22:12:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581459138; bh=yNqZod946paujAdEqMRJ1ejAWBjSCe4eeJhwXaauReA=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=CIBIe+lFFTrJtJr5PAHqlakYHlpJHZ8/IxM6nu6BnvrvP7QlnGB0UYifJ+cLbPD1u h1S/MFtkHV/kfSrWKBYyT33E1VvxImKO4GN0JxCZomOMAUqT1BPCihhCIlujCDaFTm +HfJXF6DSOj/kVMp23bh1nYVKiS1eqyxL1JzNMCc= Received: by mail-wr1-f41.google.com with SMTP id z3so14535033wru.3 for ; Tue, 11 Feb 2020 14:12:17 -0800 (PST) X-Gm-Message-State: APjAAAVqzWcHausQQ32fhuvb2s11PIhcsFZjgQLbZXmFOZ8XGwct8piG 7TwUko/dkEfzbgx9Kb4xMLB6aVa/M+A1/AZqOcav7w== X-Google-Smtp-Source: APXvYqx/FE/ZBM/IRE/iZmNcUdhlAsvuwyZQ8jxjO4FhrLlV/QjKqYE4nFeb7APUWZqWIeFWsWQE68sUQ55NIG/jAcY= X-Received: by 2002:a5d:494b:: with SMTP id r11mr10779334wrs.184.1581459136232; Tue, 11 Feb 2020 14:12:16 -0800 (PST) MIME-Version: 1.0 References: <20200211135256.24617-1-joro@8bytes.org> <20200211145008.GT14914@hirez.programming.kicks-ass.net> <20200211154321.GB22063@8bytes.org> In-Reply-To: <20200211154321.GB22063@8bytes.org> From: Andy Lutomirski Date: Tue, 11 Feb 2020 14:12:04 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC PATCH 00/62] Linux as SEV-ES Guest Support To: Joerg Roedel Cc: Peter Zijlstra , X86 ML , "H. Peter Anvin" , Andy Lutomirski , Dave Hansen , Thomas Hellstrom , Jiri Slaby , Dan Williams , Tom Lendacky , Juergen Gross , Kees Cook , LKML , kvm list , Linux Virtualization , Joerg Roedel Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 11, 2020 at 7:43 AM Joerg Roedel wrote: > > On Tue, Feb 11, 2020 at 03:50:08PM +0100, Peter Zijlstra wrote: > > > Oh gawd; so instead of improving the whole NMI situation, AMD went and > > made it worse still ?!? > > Well, depends on how you want to see it. Under SEV-ES an IRET will not > re-open the NMI window, but the guest has to tell the hypervisor > explicitly when it is ready to receive new NMIs via the NMI_COMPLETE > message. NMIs stay blocked even when an exception happens in the > handler, so this could also be seen as a (slight) improvement. > I don't get it. VT-x has a VMCS bit "Interruptibility state"."Blocking by NMI" that tracks the NMI masking state. Would it have killed AMD to solve the problem they same way to retain architectural behavior inside a SEV-ES VM? --Andy