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 08FA421A18AAB for ; Mon, 29 May 2017 02:06:27 -0700 (PDT) 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 33F4B3B707; Mon, 29 May 2017 09:07:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 33F4B3B707 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=lersek@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 33F4B3B707 Received: from lacos-laptop-7.usersys.redhat.com (ovpn-116-94.phx2.redhat.com [10.3.116.94]) by smtp.corp.redhat.com (Postfix) with ESMTP id A659C18179; Mon, 29 May 2017 09:07:22 +0000 (UTC) To: Brijesh Singh , edk2-devel@lists.01.org Cc: Thomas.Lendacky@amd.com, leo.duran@amd.com, Jordan Justen References: <1495809845-32472-1-git-send-email-brijesh.singh@amd.com> <1495809845-32472-8-git-send-email-brijesh.singh@amd.com> From: Laszlo Ersek Message-ID: Date: Mon, 29 May 2017 11:07:21 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <1495809845-32472-8-git-send-email-brijesh.singh@amd.com> 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 [10.5.110.30]); Mon, 29 May 2017 09:07:24 +0000 (UTC) Subject: Re: [PATCH v6 07/17] OvmfPkg: Introduce IoMmuAbsent Protocol GUID 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: Mon, 29 May 2017 09:06:27 -0000 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 05/26/17 16:43, Brijesh Singh wrote: > Platforms that optionally provide an IOMMU protocol should do so by > including a DXE driver (usually called IoMmuDxe) that produces either > the IOMMU protocol -- if the underlying capabilities are available --, > or gIoMmuAbsentProtocolGuid, to signal that the IOMMU capability > detection completed with negative result (i.e., no IOMMU will be > available in the system). > > In turn, DXE drivers (and library instances) that are supposed to use > the IOMMU protocol if it is available should add the following to > their DEPEX: > > gEdkiiIoMmuProtocolGuid OR gIoMmuAbsentProtocolGuid > > This ensures these client modules will only be dispatched after IOMMU > detection completes (with positive or negative result). > > > Cc: Jordan Justen > Cc: Laszlo Ersek > Cc: Leo Duran > Contributed-under: TianoCore Contribution Agreement 1.0 > Suggested-by: Jordan Justen > Suggested-by: Laszlo Ersek > Signed-off-by: Brijesh Singh > --- > OvmfPkg/OvmfPkg.dec | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec > index 5627be0bab0a..4241af10c3d0 100644 > --- a/OvmfPkg/OvmfPkg.dec > +++ b/OvmfPkg/OvmfPkg.dec > @@ -69,6 +69,7 @@ [Protocols] > gBlockMmioProtocolGuid = {0x6b558ce3, 0x69e5, 0x4c67, {0xa6, 0x34, 0xf7, 0xfe, 0x72, 0xad, 0xbe, 0x84}} > gXenBusProtocolGuid = {0x3d3ca290, 0xb9a5, 0x11e3, {0xb7, 0x5d, 0xb8, 0xac, 0x6f, 0x7d, 0x65, 0xe6}} > gXenIoProtocolGuid = {0x6efac84f, 0x0ab0, 0x4747, {0x81, 0xbe, 0x85, 0x55, 0x62, 0x59, 0x04, 0x49}} > + gIoMmuAbsentProtocolGuid = {0xf8775d50, 0x8abd, 0x4adf, {0x92, 0xac, 0x85, 0x3e, 0x51, 0xf6, 0xc8, 0xdc}} > > [PcdsFixedAtBuild] > gUefiOvmfPkgTokenSpaceGuid.PcdOvmfPeiMemFvBase|0x0|UINT32|0 > Reviewed-by: Laszlo Ersek