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 ABB91D3399B for ; Mon, 28 Oct 2024 17:05:22 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t5TAe-0002vU-QX; Mon, 28 Oct 2024 13:04:50 -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 1t5TAc-0002ui-8t for qemu-devel@nongnu.org; Mon, 28 Oct 2024 13:04:46 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t5TAa-0003gl-Ht for qemu-devel@nongnu.org; Mon, 28 Oct 2024 13:04:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1730135083; 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=NQu+8I7Sok3PPSrWFRnNNqhfVgvV3ebDTRz6eG60lgs=; b=coZPHvQXUMrufm+1kPj5OWKECUwEwMBSDoaLF2WoKQyjleqdTn7cWljdmDt/eSECCuw+eM AaRd3n2CsoOzVYLHfHf59YznKl02HVreIPafdj21eTXwgDiSxEYX80Dcf0ZWHVhnFC243O JDVWwbXo5HRkDX/rKP5hjwGNu/4wrnc= 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-328-jh4yBVELOw2Tk0UapQ0TwQ-1; Mon, 28 Oct 2024 13:04:40 -0400 X-MC-Unique: jh4yBVELOw2Tk0UapQ0TwQ-1 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (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 DF7481955EB5; Mon, 28 Oct 2024 17:04:37 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.86]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id E381B1956088; Mon, 28 Oct 2024 17:04:30 +0000 (UTC) Date: Mon, 28 Oct 2024 17:04:27 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Peter Maydell Cc: Eric Auger , eric.auger.pro@gmail.com, cohuck@redhat.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, kvmarm@lists.linux.dev, richard.henderson@linaro.org, alex.bennee@linaro.org, maz@kernel.org, oliver.upton@linux.dev, sebott@redhat.com, shameerali.kolothum.thodi@huawei.com, armbru@redhat.com, abologna@redhat.com, jdenemar@redhat.com, shahuang@redhat.com, mark.rutland@arm.com, philmd@linaro.org, pbonzini@redhat.com Subject: Re: [RFC 18/21] arm/cpu: Introduce a customizable kvm host cpu model Message-ID: References: <20241025101959.601048-1-eric.auger@redhat.com> <20241025101959.601048-19-eric.auger@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.12 (2023-09-09) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 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: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.373, 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: , 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 Mon, Oct 28, 2024 at 04:48:18PM +0000, Peter Maydell wrote: > On Mon, 28 Oct 2024 at 16:35, Daniel P. Berrangé wrote: > > > > On Mon, Oct 28, 2024 at 04:16:31PM +0000, Peter Maydell wrote: > > > On Fri, 25 Oct 2024 at 14:24, Daniel P. Berrangé wrote: > > > > On Fri, Oct 25, 2024 at 03:18:25PM +0200, Eric Auger wrote: > > > > > On 10/25/24 15:06, Daniel P. Berrangé wrote: > > > > > > Also, is this naming convention really the same one that users > > > > > > will see when they look at /proc/cpuinfo to view features ? It > > > > > No it is not. I do agree that the custom cpu model is very low level. It > > > > > is very well suited to test all series turning ID regs as writable but > > > > > this would require an extra layer that adapts /proc/cpuinfo feature > > > > > level to this regid/field abstraction. > > > > > > > > > > In /cpu/proc you will see somethink like: > > > > > Features : fp asimd evtstrm aes pmull sha1 sha2 crc32 atomics fphp > > > > > asimdhp cpuid asimdrdm lrcpc dcpop asimddp > > > > > > > > Right, IMHO, this is the terminology that QEMU must use in user > > > > facing APIs. > > > > > > /proc/cpuinfo's naming is rather weird for historical > > > reasons (for instance there is only one FEAT_FP16 feature > > > but cpuinfo lists "fphp" and "asimdhp" separately). > > > > There's plenty of wierd history in x86 too. In this > > case I might suggest just picking one of the two > > common names, and ignoring the other. > > > > If we really wanted to, we could alias the 2nd name > > to the first, but its likely not worth the bother. > > Or we could use the standard set of architectural > feature names, and not have the problem at all, and not > have to document what we mean by our nonstandard names. > (cpuinfo names do actually mostly line up with the > standard names, just not 100%. Similarly gcc/clang command > line options are mostly the architectural feature name.) Ah, right, yes. Sorry I mis-understood you originally to be suggesting the same low level names as this patch. 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 :|