Received: by 2002:a05:6a10:a841:0:0:0:0 with SMTP id d1csp3701558pxy; Mon, 26 Apr 2021 07:52:00 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzE4rWB41gnxN2ah3+T6XAuvOQI3xlLEIi7pMfJuQeSo0LmyTbN8au9yZ5uqYoZDd+PctG/ X-Received: by 2002:a17:90a:bb93:: with SMTP id v19mr9460883pjr.127.1619448720008; Mon, 26 Apr 2021 07:52:00 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1619448719; cv=none; d=google.com; s=arc-20160816; b=Ai9/sep4lk+lRpZ9VJviNulEhxZJykAOiF1/Koh/PFW5gIM8c+6hlEtksVpMPL2FEw GZMXIpwJ6Qrj+B77bFOUIwm5ZCUJ5YnwZ6oorA+ICO9AGC3MQvP0bBiNtbMA7YTLexZ/ LJWz1tQA1vwzgHmdXfh8OoYeh3snGms4ghwQIhoCIY7Vn7w+QINfupF9cUJr2xl4oq1R yTb3MLCnd4c9E6yEq5lFt+rPhMydsjJhQICGIYbtbMW0DyreASPU454wYHQs63Dvi1r9 nTnZjxX1Gl3EoPQUXxX1GmZAG+zcGithiWWAxHjQltzmEjJNdD2JyE/vyEdCgZO0eP2R 2k2w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date:ironport-sdr :ironport-sdr; bh=OPHVKGc7kW/q4w/iUBMz0psG6xs91Xy+xicS8VxDjHA=; b=JiRiGSQnssL8xKba2Ht7rPT9RiqR1UC8d+cPBZmlt5REWAuvuwHShaJVKUajez/16/ vr3VJwe54Ixm/2pCedrD7Ip/zUvO33s8nJVqklmAVrkSH4kx+P2k52Jlye/8LMGroMIK cCRFryPZp4gwfq35NcLUNoufqvlAVBxKe+H3KQ5oEO2xtYe0beovCxQ5f2zjC5lfpKmV 9/m4xJxKQfLeJ19M9iwLIoHTzGDU2m//u1UXbQWy6wLof2XUeJknrtp9VXf8ZcUYizkQ rIlQSxUmUIY0jUK5WsHdj1OXeH6rXzDVCs9fy0p+jLL++XRFcdvWFWyh7DNgmvRbvL28 7W/A== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id q19si4250594plk.136.2021.04.26.07.51.47; Mon, 26 Apr 2021 07:51:59 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=intel.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233829AbhDZOvs (ORCPT + 99 others); Mon, 26 Apr 2021 10:51:48 -0400 Received: from mga11.intel.com ([192.55.52.93]:21832 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232575AbhDZOvr (ORCPT ); Mon, 26 Apr 2021 10:51:47 -0400 IronPort-SDR: IEX33GqCT5lFOVs2nGOjnXkmALLALnpeEKBcGZqB6meZp1/fusgS5v4ikwacYx1NlzHlJZhOjI +hxID+ImWsZw== X-IronPort-AV: E=McAfee;i="6200,9189,9966"; a="193159518" X-IronPort-AV: E=Sophos;i="5.82,252,1613462400"; d="scan'208";a="193159518" Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Apr 2021 07:51:05 -0700 IronPort-SDR: B5X7ktmXc2xBxLtvvCf8gK8EeCArF9unwmaSxwOKWRwzj/46PQ5PBSKzofelvtbM8mvFK/lFJB Mqpx6m2F8l2g== X-IronPort-AV: E=Sophos;i="5.82,252,1613462400"; d="scan'208";a="424923296" Received: from tassilo.jf.intel.com ([10.54.74.11]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Apr 2021 07:51:05 -0700 Date: Mon, 26 Apr 2021 07:51:04 -0700 From: Andi Kleen To: Paolo Bonzini Cc: Lai Jiangshan , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, LKML , Josh Poimboeuf , Uros Bizjak , Andy Lutomirski , Steven Rostedt Subject: Re: [PATCH v2 2/2] KVM: VMX: Invoke NMI handler via indirect call instead of INTn Message-ID: <20210426145104.GW1401198@tassilo.jf.intel.com> References: <20200915191505.10355-1-sean.j.christopherson@intel.com> <20200915191505.10355-3-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > The original code "int $2" can provide the needed CPU-hidden-NMI-masked > > when entering #NMI, but I doubt it about this change. > > How would "int $2" block NMIs? The hidden effect of this change (and I > should have reviewed better the effect on the NMI entry code) is that the > call will not use the IST anymore. My understanding is that int $2 does not block NMIs. So reentries might have been possible. -Andi