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 5F9B7CF0450 for ; Wed, 9 Oct 2024 11:02:36 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1syUS8-00058u-4K; Wed, 09 Oct 2024 07:02:00 -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 1syUS5-00058k-Ey for qemu-devel@nongnu.org; Wed, 09 Oct 2024 07:01:59 -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 1syUS1-0000jE-FY for qemu-devel@nongnu.org; Wed, 09 Oct 2024 07:01:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1728471710; 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; bh=t6RToIOIInueBfGlqDm8R2r+NzyBmcTn20BVxveT/gw=; b=hBzvrtXOYGQwJPLzgkktEb1Aq+Jf9Ji/SQ9yW1PZqVCU+hbEfoq7h7NrIKChNu1JEEVzsE oiK3PUPdGBbs1+aM/fdWbyxUYVr+XWkZCc1BRmRhmIFVPtTvlaD6sOoxzW2IAMU+uSwAIX 3vnjcMtKE1ptsZEiLe99TZXNPYxmgAE= Received: from mx-prod-mc-04.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-693-O0HNyGQdPma5R2PRVs9mzg-1; Wed, 09 Oct 2024 07:01:47 -0400 X-MC-Unique: O0HNyGQdPma5R2PRVs9mzg-1 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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 01AF71955F3F; Wed, 9 Oct 2024 11:01:45 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.47]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C070519560A3; Wed, 9 Oct 2024 11:01:43 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 91C0321E6A28; Wed, 9 Oct 2024 13:01:40 +0200 (CEST) From: Markus Armbruster To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Richard Henderson , Eduardo Habkost , =?utf-8?Q?Daniel_P=2E_Berrang=C3=A9?= Subject: x86 CPU properties "family", "model", "stepping", "tsc-freq" Date: Wed, 09 Oct 2024 13:01:40 +0200 Message-ID: <87wmihr14b.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) 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=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.151, 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_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org QOM properties serve several purposes: initial configuration (external interface), run time control and monitoring (external interface), and internal purposes like versioning. Which purpose(s) a property serves is often unclear. The x86 CPU properties "family", "model", and "stepping" are used internally; see target/i386/cpu.c and hw/i386/pc.c. I figure changing them at run time makes no sense. What about configuration? Can the user set arbitrary CPU properties? If yes, are these properties meant to be set by the user? Property "tsc-freq" seems not to be used internally. I figure changing it at run time makes no sense. Looks like it is be meant to be set by the user: x86_cpu_parse_featurestr() seems to parse it from the argument of -cpu. Correct? Note that -cpu help doesn't mention it.