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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 0B7A7C35FFA for ; Wed, 19 Mar 2025 12:22:11 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tusQX-00068o-60; Wed, 19 Mar 2025 08:21:41 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tusQ1-00065x-B7 for qemu-devel@nongnu.org; Wed, 19 Mar 2025 08:21:13 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tusPz-0003Ef-1C for qemu-devel@nongnu.org; Wed, 19 Mar 2025 08:21:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1742386863; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zWkcSmJJjrpvlLQDeKOoXBqNCpSRqrAjjYDVA3kPWeQ=; b=fEY7mEVwerA9CRwCqGdaWpCYvXbh+R5t/YHRkz1PkYDN1JZV57ymZm8VVxFluf8laQZWB0 H3J9gW0ylvTrW8cexrBt2Oz1EyAwYjjs8FlsBvUd2fuT5zsOwvlzGCAwhR+hzSU2qrrjH8 tsEuIjZz3eCWxDuOgMZ6MT/leEVi018= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-511-yVzpJK-dMMalTqEkxvErFw-1; Wed, 19 Mar 2025 08:21:00 -0400 X-MC-Unique: yVzpJK-dMMalTqEkxvErFw-1 X-Mimecast-MFC-AGG-ID: yVzpJK-dMMalTqEkxvErFw_1742386859 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 3D7D01801A07; Wed, 19 Mar 2025 12:20:59 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.112]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id BC3F81955BC2; Wed, 19 Mar 2025 12:20:57 +0000 (UTC) Date: Wed, 19 Mar 2025 12:20:54 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Gerd Hoffmann Cc: qemu-devel@nongnu.org, Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Kashyap Chamarthy Subject: Re: [PATCH v2 4/4] docs/firmware: add feature flag for qemu variable store Message-ID: References: <20250319110152.1309969-1-kraxel@redhat.com> <20250319110152.1309969-5-kraxel@redhat.com> <46ersbz6ema7tj6eei7d6rmr5nyaz4zultzdhhlc6ncaqtucn2@tcmnl6gb3jfz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <46ersbz6ema7tj6eei7d6rmr5nyaz4zultzdhhlc6ncaqtucn2@tcmnl6gb3jfz> User-Agent: Mutt/2.2.13 (2024-03-09) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -23 X-Spam_score: -2.4 X-Spam_bar: -- X-Spam_report: (-2.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.337, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Mar 19, 2025 at 12:51:16PM +0100, Gerd Hoffmann wrote: > On Wed, Mar 19, 2025 at 11:37:40AM +0000, Daniel P. Berrangé wrote: > > > > > > +# @qemu-vars: The firmware expects qemu to provide an efi variable > > > > > +# store, via "uefi-vars-sysbus" or "uefi-vars-x64" device. > > > > I wonder if 'qemu-vars' is the right name here ? It feels like the specification > > for such device is effectively defined by UEFI, with any hypervisor providing a > > impl. Perhaps just call it 'uefi-vars-dev' or some name that's relevant for > > what EDK2 calls it ? > > 'host-uefi-vars' maybe? Or 'vmm-uefi-vars'? > > > > There is 'stateless' already for 'firmware image in r/o flash'. > > > > What's the behaviour of UEFI if build with JSON vars support, but without > > QEMU providing any JSON vars backend ? > > It will panic. In that case, we must not reuse 'stateless' with such builds, as that's quite different semantics & incompatible with current usage. We would need a new 'uefi-vars' mode, or just declare that we must always use 'memory' not 'flash' for such builds. > > > We would want to expand the 'stateless' docs to mention that this feature > > flag indicates optional support for persistence in that case. > > Optional is not possible do due to the way variable store support is > organized in edk2. Firmware can't switch between smm and non-smm > configuration at runtime for similar reasons. > > take care, > Gerd > With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|