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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 079ECC3A589 for ; Tue, 20 Aug 2019 08:35:44 +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 CD2A82339E for ; Tue, 20 Aug 2019 08:35:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CD2A82339E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34718 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hzzcE-0000E8-SF for qemu-devel@archiver.kernel.org; Tue, 20 Aug 2019 04:35:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55755) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1hzzbZ-00089B-LJ for qemu-devel@nongnu.org; Tue, 20 Aug 2019 04:35:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hzzbX-0001f8-IA for qemu-devel@nongnu.org; Tue, 20 Aug 2019 04:35:00 -0400 Received: from mga11.intel.com ([192.55.52.93]:56735) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hzzbX-0001UI-7D for qemu-devel@nongnu.org; Tue, 20 Aug 2019 04:34:59 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Aug 2019 01:34:46 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,408,1559545200"; d="scan'208";a="378484663" Received: from txu2-mobl.ccr.corp.intel.com (HELO [10.239.196.137]) ([10.239.196.137]) by fmsmga006.fm.intel.com with ESMTP; 20 Aug 2019 01:34:44 -0700 To: Igor Mammedov , Dan Williams References: <20190809065731.9097-1-tao3.xu@intel.com> <20190809065731.9097-6-tao3.xu@intel.com> <20190813170027.0617b129@redhat.com> <789df028-9dd9-884a-2493-aecc9a646e63@intel.com> <20190816165758.47042712@redhat.com> From: Tao Xu Message-ID: Date: Tue, 20 Aug 2019 16:34:44 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190816165758.47042712@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.93 Subject: Re: [Qemu-devel] [PATCH v9 05/11] numa: Extend CLI to provide initiator information for numa nodes 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: , Cc: Eduardo Habkost , "Liu, Jingqi" , "Du, Fan" , Qemu Developers , "daniel@linux.ibm.com" , Jonathan Cameron Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 8/16/2019 10:57 PM, Igor Mammedov wrote: > On Wed, 14 Aug 2019 19:31:27 -0700 > Dan Williams wrote: > >> On Wed, Aug 14, 2019 at 6:57 PM Tao Xu wrote: >>> >>> On 8/15/2019 5:29 AM, Dan Williams wrote: >>>> On Tue, Aug 13, 2019 at 10:14 PM Tao Xu wrote: >>>>> >>>>> On 8/14/2019 10:39 AM, Dan Williams wrote: >>>>>> On Tue, Aug 13, 2019 at 8:00 AM Igor Mammedov wrote: >>>>>>> >>>>>>> On Fri, 9 Aug 2019 14:57:25 +0800 >>>>>>> Tao wrote: >>>>>>> >>>>>>>> From: Tao Xu >>>>>>>> >>> [...] >>>>>>>> + for (i = 0; i < machine->numa_state->num_nodes; i++) { >>>>>>>> + if (numa_info[i].initiator_valid && >>>>>>>> + !numa_info[numa_info[i].initiator].has_cpu) { >>>>>>> ^^^^^^^^^^^^^^^^^^^^^^ possible out of bounds read, see bellow >>>>>>> >>>>>>>> + error_report("The initiator-id %"PRIu16 " of NUMA node %d" >>>>>>>> + " does not exist.", numa_info[i].initiator, i); >>>>>>>> + error_printf("\n"); >>>>>>>> + >>>>>>>> + exit(1); >>>>>>>> + } >>>>>>> it takes care only about nodes that have cpus or memory-only ones that have >>>>>>> initiator explicitly provided on CLI. And leaves possibility to have >>>>>>> memory-only nodes without initiator mixed with nodes that have initiator. >>>>>>> Is it valid to have mixed configuration? >>>>>>> Should we forbid it? >>>>>> >>>>>> The spec talks about the "Proximity Domain for the Attached Initiator" >>>>>> field only being valid if the memory controller for the memory can be >>>>>> identified by an initiator id in the SRAT. So I expect the only way to >>>>>> define a memory proximity domain without this local initiator is to >>>>>> allow specifying a node-id that does not have an entry in the SRAT. >>>>>> >>>>> Hi Dan, >>>>> >>>>> So there may be a situation for the Attached Initiator field is not >>>>> valid? If true, I would allow user to input Initiator invalid. >>>> >>>> Yes it's something the OS needs to consider because the platform may >>>> not be able to meet the constraint that a single initiator is >>>> associated with the memory controller for a given memory target. In >>>> retrospect it would have been nice if the spec reserved 0xffffffff for >>>> this purpose, but it seems "not in SRAT" is the only way to identify >>>> memory that is not attached to any single initiator. >>>> >>> But As far as I konw, QEMU can't emulate a NUMA node "not in SRAT". I am >>> wondering if it is effective only set Initiator invalid? >> >> You don't need to emulate a NUMA node not in SRAT. Just put a number >> in this HMAT entry larger than the largest proximity domain number >> found in the SRAT. >>> >> > > So behavior is really not defined in the spec > (well I wasn't able to convince myself that above behavior is in the spec). > > In this case I'd go with a strict check for now not allowing invalid initiator > (we can easily relax check and allow it point to nonsense later but no other way around) > So let me summarize the solution, in order to avoid misunderstanding, if there are something wrong, pls tell me: 1) -machine,hmat=yes -object memory-backend-ram,size=1G,id=m0 \ -object memory-backend-ram,size=1G,id=m1 \ -object memory-backend-ram,size=1G,id=m2 \ -numa node,nodeid=0,memdev=m0 \ -numa node,nodeid=1,memdev=m1,initiator=0 \ -numa node,nodeid=2,memdev=m2,initiator=0 \ -numa cpu,node-id=0,socket-id=0 \ -numa cpu,node-id=0,socket-id=1 then qemu can use HMAT. 2) if initiator this case: -numa node,nodeid=0,memdev=m0 \ -numa node,nodeid=1,memdev=m1,initiator=0 \ -numa node,nodeid=2,memdev=m2 then qemu can't boot and show error message. 3) if initiator this case: -numa node,nodeid=0,memdev=m0 \ -numa node,nodeid=1,memdev=m1,initiator=0 \ -numa node,nodeid=2,memdev=m2,initiator=1 then qemu can boot and the initiator of nodeid=2 is invalid.