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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 C6F66C43331 for ; Thu, 5 Sep 2019 15:45:55 +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 4E51D207E0 for ; Thu, 5 Sep 2019 15:45:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4E51D207E0 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]:47600 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i5txK-00057L-SP for qemu-devel@archiver.kernel.org; Thu, 05 Sep 2019 11:45:54 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48042) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i5twc-0004as-SO for qemu-devel@nongnu.org; Thu, 05 Sep 2019 11:45:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i5twb-0006rn-Ki for qemu-devel@nongnu.org; Thu, 05 Sep 2019 11:45:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34491) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i5twb-0006rJ-Bx for qemu-devel@nongnu.org; Thu, 05 Sep 2019 11:45:09 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C49561056FB1; Thu, 5 Sep 2019 15:45:07 +0000 (UTC) Received: from localhost (unknown [10.43.2.182]) by smtp.corp.redhat.com (Postfix) with ESMTP id 143DA60C63; Thu, 5 Sep 2019 15:45:04 +0000 (UTC) Date: Thu, 5 Sep 2019 17:45:03 +0200 From: Igor Mammedov To: Laszlo Ersek Message-ID: <20190905174503.2acaa46a@redhat.com> In-Reply-To: References: <8091f6e8-b1ec-f017-1430-00b0255729f4@redhat.com> <7f2d2f1e-2dd8-6914-c55e-61067e06b142@redhat.com> <3661c0c5-3da4-1453-a66a-3e4d4022e876@redhat.com> <74D8A39837DF1E4DA445A8C0B3885C503F76FDAF@shsmsx102.ccr.corp.intel.com> <74D8A39837DF1E4DA445A8C0B3885C503F7728AB@shsmsx102.ccr.corp.intel.com> <20190827203102.56d0d048@redhat.com> <033ced1a-1399-968e-cce6-6b15a20b0baf@redhat.com> <20190830164802.1b17ff26@redhat.com> <20190902104534.46e58c95@redhat.com> <2ef1910e-8879-028a-4db6-97a0ecc64083@redhat.com> <20190903165355.27e1eee0@redhat.com> <17985043-f16c-0ff4-6f60-b6762d72e848@redhat.com> <20190904115207.76bc6bfe@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.64]); Thu, 05 Sep 2019 15:45:07 +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 , "Yao, Jiewen" , "Nakajima, Jun" , "Kinney, Michael D" , Paolo Bonzini , Boris Ostrovsky , "rfc@edk2.groups.io" , Joao Marcal Lemos Martins Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, 5 Sep 2019 15:08:31 +0200 Laszlo Ersek wrote: > On 09/04/19 11:52, Igor Mammedov wrote: > > > it could be stolen RAM + black hole like TSEG, assuming fw can live without RAM(0x30000+128K) range > > (in this case fwcfg interface would only work for locking down the range) > > > > or > > > > we can actually have a dedicated SMRAM (like in my earlier RFC), > > in this case FW can use RAM(0x30000+128K) when SMRAM isn't mapped into RAM address space > > (in this case fwcfg would be used to temporarily map SMRAM into normal RAM and unmap/lock > > after SMI relocation handler was initialized). > > > > If possible I'd prefer a simpler TSEG like variant. > > I think TSEG-like behavior is between these two. That is, I believe we > should have explicit open/close/lock operations. And, when the range is > closed (meaning, closed+unlocked, or closed+locked), then the black hole > should take effect for code that's not running in SMM. > > Put differently, its like the second choice, except the range never > appears as normal RAM. "When SMRAM isn't mapped into RAM address space", > then the address range shows "nothing" (black hole). I guess we at point where patch is better then words, I'll send one as reply here shortly. I've just implemented subset of above (opened, closed+locked). > Regarding "fw can live without RAM(0x30000+128K) range" -- do you mean > whether the firmware could use another RAM area for fw_cfg DMA? > > If that's the question, then I wouldn't worry about it. I'd remove the > 0x30000+128K range from the memory map, so the fw_cfg stuff (or anything > else) would never allocate memory from the range. It's much more > concerning to me however how the SMM infrastructure would deal with a > hole in the memory map right there. I didn't mean fwcfg in this context, what I meant if firmware were able to avoid using RAM(0x30000+128K) range (since it becomes unusable after locking). Looks like you just answered it here