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 62B7CC47BE6 for ; Tue, 6 Jan 2026 11:21:55 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vd57f-0001MG-9G; Tue, 06 Jan 2026 06:21:11 -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 1vd57d-0001Ih-JS for qemu-devel@nongnu.org; Tue, 06 Jan 2026 06:21:09 -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 1vd57b-0007Ld-G5 for qemu-devel@nongnu.org; Tue, 06 Jan 2026 06:21:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1767698465; 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:in-reply-to:in-reply-to: references:references; bh=6TSnBYpu77LgY4uEe3T1qDQ876+0AwDSHt8tLb+vo0g=; b=JN/3mkxpYZ4d7FugFaZCvmttsyArTQpM+BuDclZbEP++obGkev6RjxEbojs9YVCDjq/fvn Z7Qjb2taEmzVUHUT95rgXax9sBup36lcRQ/r0ziWeX+NQESAWk+rVR5OnGeW8QZDgxKctI MWO8I9N6Oeq1/cMjzG5owFhLOXeKRNw= Received: from mx-prod-mc-03.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-481-0FAolGA2PleQ0SscAu4T7g-1; Tue, 06 Jan 2026 06:21:03 -0500 X-MC-Unique: 0FAolGA2PleQ0SscAu4T7g-1 X-Mimecast-MFC-AGG-ID: 0FAolGA2PleQ0SscAu4T7g_1767698462 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-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E65FB195605A; Tue, 6 Jan 2026 11:21:01 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.217]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0F04C19560AB; Tue, 6 Jan 2026 11:20:59 +0000 (UTC) Date: Tue, 6 Jan 2026 11:20:56 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Zhao Liu Cc: Paolo Bonzini , qemu-devel@nongnu.org, Xudong Hao , Yu Chen Subject: Re: [PATCH 10/10] dosc/cpu-models-x86: Add documentation for DiamondRapids Message-ID: References: <20251120071030.961230-1-zhao1.liu@intel.com> <20251120071030.961230-11-zhao1.liu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20251120071030.961230-11-zhao1.liu@intel.com> User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 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: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-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 Thu, Nov 20, 2025 at 03:10:30PM +0800, Zhao Liu wrote: > Current DiamondRapids hasn't supported cache model. Instead, document > its special CPU & cache topology to allow user emulate with "-smp" & > "-machine smp-cache". > > Cc: Yu Chen > Signed-off-by: Zhao Liu > --- > docs/system/cpu-models-x86.rst.inc | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) > > diff --git a/docs/system/cpu-models-x86.rst.inc b/docs/system/cpu-models-x86.rst.inc > index 6a770ca8351c..c4c8fc67a562 100644 > --- a/docs/system/cpu-models-x86.rst.inc > +++ b/docs/system/cpu-models-x86.rst.inc > @@ -71,6 +71,26 @@ mixture of host CPU models between machines, if live migration > compatibility is required, use the newest CPU model that is compatible > across all desired hosts. > > +``DiamondRapids`` > + Intel Xeon Processor. > + > + Diamond Rapids product has a topology which differs from previous Xeon > + products. It does not support SMT, but instead features a dual core > + module (DCM) architecture. It also has core building blocks (CBB - die > + level in CPU topology). The cache hierarchy is organized as follows: > + L1 i/d cache is per thread, L2 cache is per DCM, and L3 cache is per > + CBB. This cache topology can be emulated for DiamondRapids CPU model > + using the smp-cache configuration as shown below: Can I request a slight rewording to simplify this: ``DiamondRapids`` Intel Xeon Processor (DiamondRapids, 2025). This does not include SMT but allows the module and die topology levels. The cache hierarchy is L1 i/d cache per thread, L2 cache per module, and L3 cache per die, which can be emulated using using the smp-cache option: Example: :: -machine smp-cache.0.cache=l1d,smp-cache.0.topology=thread,\ smp-cache.1.cache=l1i,smp-cache.1.topology=thread,\ smp-cache.2.cache=l2,smp-cache.2.topology=module,\ smp-cache.3.cache=l3,smp-cache.3.topology=die,\ ... 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 :|