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=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,RCVD_ILLEGAL_IP, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 AACB1C388F7 for ; Tue, 3 Nov 2020 05:36:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 43A7B2225E for ; Tue, 3 Nov 2020 05:36:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727424AbgKCFg1 (ORCPT ); Tue, 3 Nov 2020 00:36:27 -0500 Received: from mga02.intel.com ([134.134.136.20]:50015 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725980AbgKCFg1 (ORCPT ); Tue, 3 Nov 2020 00:36:27 -0500 IronPort-SDR: MYp7U9pZXSVy6xlP0yKBXYMKQ1RkknhfFm6lrrxcIY9NsQJt8zlJrvAxlQ5mDCGZX0kqH9NnKA MVK7wHHnsILw== X-IronPort-AV: E=McAfee;i="6000,8403,9793"; a="155989880" X-IronPort-AV: E=Sophos;i="5.77,447,1596524400"; d="scan'208";a="155989880" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Nov 2020 21:36:25 -0800 IronPort-SDR: X6u1oR2wAu1++657bT/db7CSkzbjkXMGxusSlH9mmpyr4mSLmulnYxsuDL8ICqK3rqNQH0YTEh VbI8/qCm3fWQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,447,1596524400"; d="scan'208";a="353085351" Received: from unknown (HELO [0.0.0.0]) ([10.109.19.69]) by fmsmga004.fm.intel.com with ESMTP; 02 Nov 2020 21:36:22 -0800 Subject: Re: [PATCH] KVM: VMX: Enable Notify VM exit To: Sean Christopherson 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 References: <20201102061445.191638-1-tao3.xu@intel.com> <20201102173236.GD21563@linux.intel.com> From: Tao Xu Message-ID: <31218420-f20c-aa7f-089d-54e9fecf35aa@intel.com> Date: Tue, 3 Nov 2020 13:36:22 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201102173236.GD21563@linux.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/3/20 1:32 AM, Sean Christopherson wrote: > 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 > OK, I will correct this.