From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E5663606A31A for ; Tue, 27 Oct 2026 06:30:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=gVxfmSMd Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1xLafr-0001qS-JP; Tue, 27 Oct 2026 02:28:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1xLafk-0001pm-Uv for qemu-devel@nongnu.org; Tue, 27 Oct 2026 02:28:37 -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 1xLafh-00088I-9s for qemu-devel@nongnu.org; Tue, 27 Oct 2026 02:28:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1793082510; h=from:from: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=tdyxn/88Lnb01SmqF7aVPO1XRx4I5EDa3qJzLSUt84M=; b=gVxfmSMdwLOrSexkxjoaY2DdWWNM/8/RbUGZG+/yjrhWSMAhwnqgKG4YWiPP0HKth+7kBx U32PDA/oJSootunv7rIw1y8bFh/5Js1XjSrDvfQ1Jh2oWSzCle8iLYQ/MfkY3VGOOmuwaG FNrHNhoBHaUObm27Ytbi+mP9QXsUjtg= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-333-6orgKz9NNWmg3O8-BPoe7g-1; Tue, 27 Oct 2026 02:28:27 -0400 X-MC-Unique: 6orgKz9NNWmg3O8-BPoe7g-1 X-Mimecast-MFC-AGG-ID: 6orgKz9NNWmg3O8-BPoe7g_1793082506 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A95141955F04; Tue, 27 Oct 2026 06:28:25 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.44.22.2]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 49BED195608B; Tue, 27 Oct 2026 06:28:25 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id DD4F821E6A04; Tue, 27 Oct 2026 07:28:22 +0100 (CET) From: Markus Armbruster To: Peter Maydell Cc: Daniel P. =?utf-8?Q?Berrang=C3=A9?= , qemu-devel@nongnu.org, David Hildenbrand , Igor Mammedov , Paolo Bonzini , Marcelo Tosatti , "Michael S. Tsirkin" , Richard Henderson Subject: Re: qemu-system-x86_64 appears to have sgx-epc, but not memory-backend-epc In-Reply-To: (Peter Maydell's message of "Fri, 23 Oct 2026 12:50:24 +0100") References: <87zew5j3iv.fsf@pond.sub.org> Date: Tue, 27 Oct 2026 07:28:22 +0100 Message-ID: <87o6cfbqt5.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 2 X-Spam_score: 0.2 X-Spam_bar: / X-Spam_report: (0.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.339, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org X-Spam-Status: No, score=-7.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Peter Maydell writes: > On Fri, 23 Oct 2026 at 12:08, Daniel P. Berrang=C3=A9 wrote: >> The memory backends are all implementing the UserCreatable >> interface, which provides a "complete" method where they >> could gracefully report lack of the feature via 'errp'. > > I didn't realize UserCreatable was a thing. It seems unfortunate > that we have accumulated three different kinds of object > creation/destruction life cycle: Yes. See also "Problem 5: QOM lacks a clear life cycle" in Subject: Dynamic & heterogeneous machines, initial configuration: probl= ems Date: Wed, 31 Jan 2024 21:14:21 +0100 Message-ID: <87o7d1i7ky.fsf@pond.sub.org> https://lore.kernel.org/qemu-devel/87o7d1i7ky.fsf@pond.sub.org/=20=20= =20=20 > - instance_init / instance_finalize All QOM types (but some add to this protocol). > - instance_init / realize / unrealize / instance_finalize Device types, i.e. subtypes of "device". > - instance_init / complete / prepare_delete / instance_finalize User-createble object types, i.e. types that provide interface "user-creatable". No device type does that. Related: machine init done notifiers.