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 7B46FD0EE04 for ; Tue, 25 Nov 2025 16:11:19 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vNvcI-0003it-DI; Tue, 25 Nov 2025 11:10:10 -0500 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 1vNvcB-0003gb-3Q for qemu-devel@nongnu.org; Tue, 25 Nov 2025 11:10:03 -0500 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 1vNvc3-0003zQ-PY for qemu-devel@nongnu.org; Tue, 25 Nov 2025 11:09:58 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1764086990; 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: in-reply-to:in-reply-to:references:references; bh=wTIv6dREnPMvXS5uJbknCLqCPpIYBaF9/FWh3NHuOks=; b=XLZAqGuBFnCqzjp/XSWnMWmwe8Sukt+4Sd2c/NuF6fJvam61Bopzq3TQTnWDhUlPR1YTmb CzkHtjhMopgjxM5MatESykcizVqO55Vhp6U5cg6r3JFrnRm03w6VBA02YaNBWB7qSSCdlD GPcu2kFSpEJAhIKywt7ZOqP32Uv4yAM= 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-401-EO9jCkBeOlq1IirmuN3SWw-1; Tue, 25 Nov 2025 11:09:46 -0500 X-MC-Unique: EO9jCkBeOlq1IirmuN3SWw-1 X-Mimecast-MFC-AGG-ID: EO9jCkBeOlq1IirmuN3SWw_1764086984 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 5C10419560B1; Tue, 25 Nov 2025 16:09:44 +0000 (UTC) Received: from localhost (dhcp-192-239.str.redhat.com [10.33.192.239]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5A71F1956056; Tue, 25 Nov 2025 16:09:43 +0000 (UTC) From: Cornelia Huck To: Peter Maydell Cc: qemu-arm@nongnu.org, qemu-devel@nongnu.org, Eric Auger Subject: Re: [PATCH for-11.0] arm: add DCZID_EL0 to idregs array In-Reply-To: Organization: "Red Hat GmbH, Sitz: Werner-von-Siemens-Ring 12, D-85630 Grasbrunn, Handelsregister: Amtsgericht =?utf-8?Q?M=C3=BCnchen=2C?= HRB 153243, =?utf-8?Q?Gesch=C3=A4ftsf=C3=BChrer=3A?= Ryan Barnhart, Charles Cachera, Avril Crosse O'Flaherty" References: <20251119134414.2892640-1-cohuck@redhat.com> User-Agent: Notmuch/0.38.3 (https://notmuchmail.org) Date: Tue, 25 Nov 2025 17:09:41 +0100 Message-ID: <87see2ozzu.fsf@redhat.com> MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Received-SPF: pass client-ip=170.10.129.124; envelope-from=cohuck@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -22 X-Spam_score: -2.3 X-Spam_bar: -- X-Spam_report: (-2.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.152, 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_H2=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=unavailable 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, Nov 24 2025, Peter Maydell wrote: > On Wed, 19 Nov 2025 at 13:44, Cornelia Huck wrote: >> >> This requires a bit of care, since we still have to handle the EL >> specific part (DCZID_EL0.DZP). Callers can set/access dcz_blocksize >> via a wrapper working on DCZID_EL.BS. >> >> KVM currently does not support DCZID_EL0 via ONE_REG, and actually >> does not need to work with it, so provide a dummy value for now. > > That seems like an odd (unintended?) omission -- is it worth > adding? (We would need to handle older kernels that don't > expose it anyway, of course.) I'm not sure whether there's actually a usecase for KVM exposing this to the VMM - AFAICS, KVM doesn't do anything special for DC ZVA and friends, and doesn't tweak HCR_EL2.TDZ which would change behaviour.