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=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 889B5C4742C for ; Mon, 2 Nov 2020 17:32:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 34C47208A9 for ; Mon, 2 Nov 2020 17:32:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727535AbgKBRcj (ORCPT ); Mon, 2 Nov 2020 12:32:39 -0500 Received: from mga09.intel.com ([134.134.136.24]:60774 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726587AbgKBRci (ORCPT ); Mon, 2 Nov 2020 12:32:38 -0500 IronPort-SDR: 5GYPaCuZgQaEpPHK3BSx7kzgVcq5QwNsINTf02SmvRsjRqBT+AOn6Jp+jZq0jzlSS/v30NMwlx A37yo2HwmaFg== X-IronPort-AV: E=McAfee;i="6000,8403,9793"; a="169054546" X-IronPort-AV: E=Sophos;i="5.77,445,1596524400"; d="scan'208";a="169054546" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Nov 2020 09:32:38 -0800 IronPort-SDR: b2zKfegSK6u2fKZJCw6Gaf/EocNmnRgzgPtTJHciwnCyb8+DMpI9FJ133BAjKXmGfOT9DNxNSc 53UxS1zaFlUw== X-IronPort-AV: E=Sophos;i="5.77,445,1596524400"; d="scan'208";a="324927291" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.160]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Nov 2020 09:32:38 -0800 Date: Mon, 2 Nov 2020 09:32:37 -0800 From: Sean Christopherson To: Tao Xu Cc: pbonzini@redhat.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Xiaoyao Li Subject: Re: [PATCH] KVM: VMX: Enable Notify VM exit Message-ID: <20201102173236.GD21563@linux.intel.com> References: <20201102061445.191638-1-tao3.xu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201102061445.191638-1-tao3.xu@intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Nov 02, 2020 at 02:14:45PM +0800, Tao Xu wrote: > There are some cases that malicious virtual machines can cause CPU stuck > (event windows don't open up), e.g., infinite loop in microcode when > nested #AC (CVE-2015-5307). No event window obviously means no events, > e.g. NMIs, SMIs, and IRQs will all be blocked, may cause the related > hardware CPU can't be used by host or other VM. > > To resolve those cases, it can enable a notify VM exit if no > event window occur in VMX non-root mode for a specified amount of > time (notify window). > > Expose a module param for setting notify window, default setting it to > the time as 1/10 of periodic tick, and user can set it to 0 to disable > this feature. > > TODO: > 1. The appropriate value of notify window. > 2. Another patch to disable interception of #DB and #AC when notify > VM-Exiting is enabled. > > Co-developed-by: Xiaoyao Li > Signed-off-by: Tao Xu > Signed-off-by: Xiaoyao Li Incorrect ordering, since you're sending the patch, you "handled" it last, therefore your SOB should come last, i.e.: Co-developed-by: Xiaoyao Li Signed-off-by: Xiaoyao Li Signed-off-by: Tao Xu