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 X-Spam-Level: X-Spam-Status: No, score=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 829BFC47082 for ; Wed, 26 May 2021 16:50:16 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id E49866113D for ; Wed, 26 May 2021 16:50:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E49866113D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:39590 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1llwjU-00047L-WF for qemu-devel@archiver.kernel.org; Wed, 26 May 2021 12:50:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39648) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1llwdi-0001VM-D9 for qemu-devel@nongnu.org; Wed, 26 May 2021 12:44:15 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:60000) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1llwdY-0003BG-Eo for qemu-devel@nongnu.org; Wed, 26 May 2021 12:44:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622047422; 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=ssHEIadIqhw7GP3pafEiXxQbT8ZQnNwRKe8Vbn6QNAc=; b=Lum8/2/PJb4D+rw4StNKpnm/YMj96b6kVffwl45pbLbyvvtMKhGmmREIxcIfoYmBjbjvc3 vUxkZWLPxxJ+kMaETeWC9VwKbD3D+Sldxdq+y25nNuaHs21MmFIXQpv/aO2tQ1GLSAgUkW TQcu88CS+MEHz7sfvmg8KLI2/AsEMR0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-32-Xn1PT7n8NEe9oiknbYIbug-1; Wed, 26 May 2021 12:43:37 -0400 X-MC-Unique: Xn1PT7n8NEe9oiknbYIbug-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9ACB01020C52; Wed, 26 May 2021 16:43:36 +0000 (UTC) Received: from redhat.com (ovpn-115-19.ams2.redhat.com [10.36.115.19]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C448D19D9D; Wed, 26 May 2021 16:43:29 +0000 (UTC) Date: Wed, 26 May 2021 17:43:26 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: qemu-devel@nongnu.org Subject: Re: [PATCH 0/2] i386: use better matching family/model/stepping for generic CPUs Message-ID: References: <20210507133650.645526-1-berrange@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210507133650.645526-1-berrange@redhat.com> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.371, 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_H4=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Paolo Bonzini , Richard Henderson , Eduardo Habkost , "Michael S. Tsirkin" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" ping On Fri, May 07, 2021 at 02:36:48PM +0100, Daniel P. Berrangé wrote: > This is in response to this bug report: > > https://gitlab.com/qemu-project/qemu/-/issues/191 > > The generic 'qemu64' and 'max' CPUs currently defined to report a > family/model/stepping that approximately corresponds to an AMD K7 > vintage architecture. The K7 series predates the introduction of > 64-bit support by AMD in the K8 series. This has been reported to > lead to LLVM complaints about generating 64-bit code for a 32-bit > CPU target > > LLVM ERROR: 64-bit code requested on a subtarget that doesn't support it! > > The bug report is fairly limited, but it suggests LLVM looks at the > family/model/stepping and decides it to be 32-bit, despite qemu64 > reporting it is 64-bit capable. I've not reproduced this myself, > however, so I'm largely trusting the original reporter's diagnosis > > Of course interpreting the family/model/stepping only makes sense > with scoped to the reported vendor ID. Under TCG, the vendor is > honoured, but AFAICT, under KVM the vendor defined by the QEMU > model model is ignored and the real host vendor passed through. > This will make the chosen family/model/stepping non-sensical when > run under KVM on an Intel host. > > None the less these patches change to report a CPUID with the > family, model and stepping taken from a > > AMD Athlon(tm) 64 X2 Dual Core Processor 4000+ > > which is one of the first 64-bit AMD CPUs. This is at least more > accurate in terms of the static CPU model definition, even if it > is still nonsense in the case where KVM overrides the vendor to > be non-AMD. > > Daniel P. Berrangé (2): > i386: use better matching family/model/stepping for 'qemu64' CPU > i386: use better matching family/model/stepping for 'max' CPU > > hw/i386/pc.c | 6 +++++- > target/i386/cpu.c | 12 +++++++++--- > 2 files changed, 14 insertions(+), 4 deletions(-) > > -- > 2.31.1 > > 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 :|