From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 7A863189B93 for ; Thu, 1 Aug 2024 11:28:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722511720; cv=none; b=Hs6h2TCVUZZS/8p8+2caLiin+HNwZvsOO+4TKLUjmkszmC1SI7HpLjPSl7x5CdlAkS87lJRhXC3GKUyXFCu34meIhhAvi4ziiQYvunwAxYuumnY1gZ8IK1l3FxuCyPY1xaTte6njnSRMmPZlh5PoF1fn77Zz5yfZTypciMLiurM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722511720; c=relaxed/simple; bh=+j+fRaXOovYjzMGUUzUtuWYeyJ1Eb5QWXviqc97u2Tg=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=S8jtRNmtFtBrQpsbRpc2RADVG4EviDYH/GhgtXRc/ntSG2GvKpv3ytDyBZuLqVmHtnwdFNyRejjwkTtCWI8jV+e5AK2HyRBBMgHR1P0uFaQo3vZfPR+qwUGqYSYqga4TEVTHSNNy1ZcWqlUDIYGQY/I8OMDDBQVmyrv0nIdcK68= 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=N04jRzRF; arc=none smtp.client-ip=170.10.129.124 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="N04jRzRF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1722511717; 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=rDxUGggwXWhjZViKaa52XrXs/fzrEJLE9M/NPwvujOg=; b=N04jRzRFIEs2ysgVCBSH+vvB1Tw62RaN36No35gsRbu+q4cJaOENLosPuUfhNgW3DGuSfM t5jw5W73srwfDrNZs22yPOAjTPv9EncJfEZUos6uh5lfhqMJnwpDLer27fwxzg2VbZjRYZ dbgbk6Q9pDZs0J7kSHuwxd0g2+DHhRo= Received: from mx-prod-mc-05.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-639-UbpUzyWTMHCWhQlKJuqY3g-1; Thu, 01 Aug 2024 07:28:34 -0400 X-MC-Unique: UbpUzyWTMHCWhQlKJuqY3g-1 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B0D291955F28; Thu, 1 Aug 2024 11:28:31 +0000 (UTC) Received: from blackfin.pond.sub.org (unknown [10.39.192.65]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 77B3419560AE; Thu, 1 Aug 2024 11:28:29 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 6556C21E6692; Thu, 1 Aug 2024 13:28:27 +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 "Thu, 1 Aug 2024 17:37:03 +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> <87le1psuv3.fsf@pond.sub.org> Date: Thu, 01 Aug 2024 13:28:27 +0200 Message-ID: <87mslweb38.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 10.30.177.12 Zhao Liu writes: > On Thu, Jul 25, 2024 at 11:07:12AM +0200, Markus Armbruster wrote: >> Date: Thu, 25 Jul 2024 11:07:12 +0200 >> From: Markus Armbruster >> Subject: Re: [PATCH 8/8] qemu-options: Add the description of smp-cache >> object >> >> 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. >> >> [...] > > Jonathan and I provided different use cases for x86 and Arm. Could we > come back here to continue the discussion? :) Can you provide a brief summary of the design alternatives that have been proposed so far? Because I've lost track.