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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 CA28EC3A5A1 for ; Thu, 22 Aug 2019 17:54:20 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9F9BA2089E for ; Thu, 22 Aug 2019 17:54:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9F9BA2089E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:46886 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i0rHv-0003yv-SE for qemu-devel@archiver.kernel.org; Thu, 22 Aug 2019 13:54:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46219) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i0rHD-0003Ty-83 for qemu-devel@nongnu.org; Thu, 22 Aug 2019 13:53:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i0rHB-0001tJ-Na for qemu-devel@nongnu.org; Thu, 22 Aug 2019 13:53:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52174) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i0rHB-0001sC-Fi for qemu-devel@nongnu.org; Thu, 22 Aug 2019 13:53:33 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6ADBA3086213; Thu, 22 Aug 2019 17:53:31 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (unknown [10.36.118.90]) by smtp.corp.redhat.com (Postfix) with ESMTP id 65A735DE5C; Thu, 22 Aug 2019 17:53:24 +0000 (UTC) To: "Kinney, Michael D" , "rfc@edk2.groups.io" , "Yao, Jiewen" , Paolo Bonzini References: <8091f6e8-b1ec-f017-1430-00b0255729f4@redhat.com> <74D8A39837DF1E4DA445A8C0B3885C503F75B680@shsmsx102.ccr.corp.intel.com> <047801f8-624a-2300-3cf7-1daa1395ce59@redhat.com> <99219f81-33a3-f447-95f8-f10341d70084@redhat.com> <6f8b9507-58d0-5fbd-b827-c7194b3b2948@redhat.com> <74D8A39837DF1E4DA445A8C0B3885C503F75FAD3@shsmsx102.ccr.corp.intel.com> <7cb458ea-956e-c1df-33f7-025e4f0f22df@redhat.com> <74D8A39837DF1E4DA445A8C0B3885C503F7600B9@shsmsx102.ccr.corp.intel.com> <20190816161933.7d30a881@x1.home> <74D8A39837DF1E4DA445A8C0B3885C503F761B96@shsmsx102.ccr.corp.intel.com> <35396800-32d2-c25f-b0d0-2d7cd8438687@redhat.com> From: Laszlo Ersek Message-ID: <98a2ba66-a42a-67e9-79b1-6d684b5e31c6@redhat.com> Date: Thu, 22 Aug 2019 19:53:18 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=iso-2022-jp Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Thu, 22 Aug 2019 17:53:31 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [edk2-rfc] [edk2-devel] CPU hotplug using SMM with QEMU+OVMF X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Chen, Yingwen" , "devel@edk2.groups.io" , Phillip Goerl , qemu devel list , Alex Williamson , "Nakajima, Jun" , Igor Mammedov , Boris Ostrovsky , Joao Marcal Lemos Martins Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 08/21/19 17:48, Kinney, Michael D wrote: > Perhaps there is a way to avoid the 3000:8000 startup > vector. > > If a CPU is added after a cold reset, it is already in a > different state because one of the active CPUs needs to > release it by interacting with the hot plug controller. > > Can the SMRR for CPUs in that state be pre-programmed to > match the SMRR in the rest of the active CPUs? > > For OVMF we expect all the active CPUs to use the same > SMRR value, so a check can be made to verify that all > the active CPUs have the same SMRR value. If they do, > then any CPU released through the hot plug controller > can have its SMRR pre-programmed and the initial SMI > will start within TSEG. Yes, that is what I proposed here: * http://mid.mail-archive.com/effa5e32-be1e-4703-4419-8866b7754e2d@redhat.com * https://edk2.groups.io/g/devel/message/45570 Namely: > When the SMM setup quiesces during normal firmware boot, OVMF could > use existent (finalized) SMBASE infomation to *pre-program* some > virtual QEMU hardware, with such state that would be expected, as > "final" state, of any new hotplugged CPU. Afterwards, if / when the > hotplug actually happens, QEMU could blanket-apply this state to the > new CPU, and broadcast a hardware SMI to all CPUs except the new one. (I know that Paolo didn't like it; I'm just confirming that I had the same, or at least a very similar, idea.) Thanks! Laszlo