From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3AB311741EF for ; Thu, 25 Jul 2024 09:07:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721898449; cv=none; b=I9qx0LXpfAqlgBWiYQqVLdye3cgZmx6ybfnNITNPuoTWo+l3+kyXVcR4j3DvCASbKgabWnxxhh3UyPOo+9Y+PAhOBScl5gTOwUPy/s/eoPlt7cvsL3rR7+QfvSD3BuPZPl4dDRZl6QRB2j7AHgRXimieTq8lj5A+4rsQQgYdRCU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721898449; c=relaxed/simple; bh=hmLcjYdcE/vztQWRL0BOKT52nohoqmeJoqS5KzADuOU=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=q71t5c98wJAgtaOhNEhJhRCc9cfZE4k1bl+Jrud55+RFLQjljOi5Cs4hSuPBnt6ah1sFeSorvcefdFdWbPLTqGZrnUIGe/18IL/l2+4u8YfbRaynTDdUx7J1OCeqGPHPW926DwfYR+/XTuW05hkga7zu5ypjL3z1eM8el9XMchs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=aQi33YOC; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aQi33YOC" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1721898446; 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=Odg2VfpZQzItX8XVDoBrE1SWurkxPgm1LLiGA3X9lMQ=; b=aQi33YOC1Q+t2SecLAExulPCiA3TpGIe991VDCLDotBjNHrIAC8r2IqDvUOmMaxF/fBeOK Xl5RoP6guSeU/EP/uzpwc+xkmWYeHut1huVN6JcmDrXJe2GX2bTnLF+1u6GiwMhSWMYWuP UCkWfDVjDuco6jE9Tvb2zuovme+cIiA= 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-604-fqqc_YYzOjK9_6D4psav9Q-1; Thu, 25 Jul 2024 05:07:20 -0400 X-MC-Unique: fqqc_YYzOjK9_6D4psav9Q-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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 B19FC1955D48; Thu, 25 Jul 2024 09:07:16 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.65]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 37AD41955D42; Thu, 25 Jul 2024 09:07:15 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id DFD0C21F4B8B; Thu, 25 Jul 2024 11:07:12 +0200 (CEST) From: Markus Armbruster To: Zhao Liu Cc: Daniel P . =?utf-8?Q?Berrang=C3=A9?= , Eduardo Habkost , Marcel Apfelbaum , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Yanan Wang , "Michael S . Tsirkin" , Paolo Bonzini , Richard Henderson , Eric Blake , Marcelo Tosatti , Alex =?utf-8?Q?Benn=C3=A9e?= , Peter Maydell , Jonathan Cameron , Sia Jee Heng , qemu-devel@nongnu.org, kvm@vger.kernel.org, qemu-riscv@nongnu.org, qemu-arm@nongnu.org, Zhenyu Wang , Dapeng Mi , Yongwei Ma Subject: Re: [PATCH 8/8] qemu-options: Add the description of smp-cache object In-Reply-To: (Zhao Liu's message of "Wed, 24 Jul 2024 22:21:10 +0800") References: <20240704031603.1744546-1-zhao1.liu@intel.com> <20240704031603.1744546-9-zhao1.liu@intel.com> <87r0bl35ug.fsf@pond.sub.org> <87bk2nnev2.fsf@pond.sub.org> Date: Thu, 25 Jul 2024 11:07:12 +0200 Message-ID: <87le1psuv3.fsf@pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 Zhao Liu writes: > Hi Markus and Daniel, > > I have the questions about the -object per cache implementation: > > On Wed, Jul 24, 2024 at 02:39:29PM +0200, Markus Armbruster wrote: >> Date: Wed, 24 Jul 2024 14:39:29 +0200 >> From: Markus Armbruster >> Subject: Re: [PATCH 8/8] qemu-options: Add the description of smp-cache >> object >> >> Zhao Liu writes: >> >> > Hi Markus, >> > >> > On Mon, Jul 22, 2024 at 03:37:43PM +0200, Markus Armbruster wrote: >> >> Date: Mon, 22 Jul 2024 15:37:43 +0200 >> >> From: Markus Armbruster >> >> Subject: Re: [PATCH 8/8] qemu-options: Add the description of smp-cache >> >> object >> >> >> >> Zhao Liu writes: >> >> >> >> > Signed-off-by: Zhao Liu >> >> >> >> This patch is just documentation. The code got added in some previous >> >> patch. Would it make sense to squash this patch into that previous >> >> patch? >> > >> > OK, I'll merge them. >> > >> >> > --- >> >> > Changes since RFC v2: >> >> > * Rewrote the document of smp-cache object. >> >> > >> >> > Changes since RFC v1: >> >> > * Use "*_cache=topo_level" as -smp example as the original "level" >> >> > term for a cache has a totally different meaning. (Jonathan) >> >> > --- >> >> > qemu-options.hx | 58 +++++++++++++++++++++++++++++++++++++++++++++++++ >> >> > 1 file changed, 58 insertions(+) >> >> > >> >> > diff --git a/qemu-options.hx b/qemu-options.hx >> >> > index 8ca7f34ef0c8..4b84f4508a6e 100644 >> >> > --- a/qemu-options.hx >> >> > +++ b/qemu-options.hx >> >> > @@ -159,6 +159,15 @@ SRST >> >> > :: >> >> > >> >> > -machine cxl-fmw.0.targets.0=cxl.0,cxl-fmw.0.targets.1=cxl.1,cxl-fmw.0.size=128G,cxl-fmw.0.interleave-granularity=512 >> >> > + >> >> > + ``smp-cache='id'`` >> >> > + Allows to configure cache property (now only the cache topology level). >> >> > + >> >> > + For example: >> >> > + :: >> >> > + >> >> > + -object '{"qom-type":"smp-cache","id":"cache","caches":[{"name":"l1d","topo":"core"},{"name":"l1i","topo":"core"},{"name":"l2","topo":"module"},{"name":"l3","topo":"die"}]}' >> >> > + -machine smp-cache=cache >> >> > ERST >> >> > >> >> > DEF("M", HAS_ARG, QEMU_OPTION_M, >> >> > @@ -5871,6 +5880,55 @@ SRST >> >> > :: >> >> > >> >> > (qemu) qom-set /objects/iothread1 poll-max-ns 100000 >> >> > + >> >> > + ``-object '{"qom-type":"smp-cache","id":id,"caches":[{"name":cache_name,"topo":cache_topo}]}'`` >> >> > + Create an smp-cache object that configures machine's cache >> >> > + property. Currently, cache property only include cache topology >> >> > + level. >> >> > + >> >> > + This option must be written in JSON format to support JSON list. >> >> >> >> Why? >> > >> > I'm not familiar with this, so I hope you could educate me if I'm wrong. >> > >> > All I know so far is for -object that defining a list can only be done in >> > JSON format and not with a numeric index like a keyval based option, like: >> > >> > -object smp-cache,id=cache0,caches.0.name=l1i,caches.0.topo=core: Parameter 'caches' is missing >> > >> > the above doesn't work. >> > >> > Is there any other way to specify a list in command line? >> >> The command line is a big, sprawling mess :) >> >> -object supports either a JSON or a QemuOpts argument. *Not* keyval! >> >> Both QemuOpts and keyval parse something like KEY=VALUE,... Keyval >> supports arrays and objects via dotted keys. QemuOpts doesn't natively >> support arrays and objects, but its users can hack around that >> limitation in various ways. -object doesn't. So you're right, it's >> JSON or bust here. >> >> However, if we used one object per cache instead, we could get something >> like >> >> -object smp-cache,name=l1d,... >> -object smp-cache,name=l1u,... >> -object smp-cache,name=l2,... >> ... > > Current, I use -object to create a smp_cache object, and link it to > MachineState by -machine,smp-cache=obj_id. > > Then for the objects per cache, how could I link them to machine? > > Is it possible that I create something static in smp_cache.c and expose > all the cache information to machine through some interface? Good questions. However, before we head deeper into the weeds here, I feel we should discuss the things below. And before we do that, I need a clear understanding of the use case. Elsewhere in this thread, I just described the use case as I understand it. Please reply there. I'll then come back to this message. [...]