From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 8ACE821A13496 for ; Tue, 2 May 2017 23:57:30 -0700 (PDT) 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 B896D37EEF; Wed, 3 May 2017 06:57:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com B896D37EEF Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=kraxel@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com B896D37EEF Received: from nilsson.home.kraxel.org (ovpn-116-124.ams2.redhat.com [10.36.116.124]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6975E77D5F; Wed, 3 May 2017 06:57:29 +0000 (UTC) Received: by nilsson.home.kraxel.org (Postfix, from userid 500) id 001AB80DE7; Wed, 3 May 2017 08:57:27 +0200 (CEST) Message-ID: <1493794647.8581.144.camel@redhat.com> From: Gerd Hoffmann To: "Kinney, Michael D" Cc: Laszlo Ersek , "Fan, Jeff" , "Yao, Jiewen" , edk2-devel-01 , Paolo Bonzini Date: Wed, 03 May 2017 08:57:27 +0200 In-Reply-To: References: <1382eb04-9646-133b-9ce5-8293cb54745f@redhat.com> Mime-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Wed, 03 May 2017 06:57:29 +0000 (UTC) Subject: Re: SMRAM sizes on large hosts X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 03 May 2017 06:57:30 -0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Di, 2017-05-02 at 20:49 +0000, Kinney, Michael D wrote: > Laszlo, >=20 > Is it possible to add more TSEG sizes to the Q35 board? qemu implements what physical q35 support. The extended smram register has two bits for the tseg size, three out of the four values are used (for 1, 2, 8 MB sizes). "11" is reserved in the specs. We could use "11" to implement a bigger tseg. Current code sets the tseg size to zero for "11". Alternatively we could add some qemu-specific register. When implementing this in qemu we will have to do it runtime-switchable, for backward compatibility with older qemu versions. So ideally firmware would detect somehow whenever qemu supports a bigger tseg or not and adapt at runtime. If edk2 can't do this we would need two edk2 builds ... cheers, Gerd