From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50981) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zo7MR-0001Zi-0j for qemu-devel@nongnu.org; Mon, 19 Oct 2015 06:08:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zo7MN-0005sb-9o for qemu-devel@nongnu.org; Mon, 19 Oct 2015 06:08:10 -0400 Received: from mga01.intel.com ([192.55.52.88]:1889) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zo7MN-0005sP-3e for qemu-devel@nongnu.org; Mon, 19 Oct 2015 06:08:07 -0400 References: <1444535584-18220-1-git-send-email-guangrong.xiao@linux.intel.com> <1444535584-18220-23-git-send-email-guangrong.xiao@linux.intel.com> <20151019095612-mutt-send-email-mst@redhat.com> <56249B59.1040103@linux.intel.com> <20151019103754-mutt-send-email-mst@redhat.com> <56249F4D.10709@linux.intel.com> <20151019121707-mutt-send-email-mst@redhat.com> <20151019114635.510b031c@igors-macbook-pro.local> From: Xiao Guangrong Message-ID: <5624BF6D.8060509@linux.intel.com> Date: Mon, 19 Oct 2015 18:01:17 +0800 MIME-Version: 1.0 In-Reply-To: <20151019114635.510b031c@igors-macbook-pro.local> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 22/32] nvdimm: init the address region used by NVDIMM ACPI List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov , "Michael S. Tsirkin" Cc: ehabkost@redhat.com, kvm@vger.kernel.org, gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, rth@twiddle.net On 10/19/2015 05:46 PM, Igor Mammedov wrote: > On Mon, 19 Oct 2015 12:17:22 +0300 > "Michael S. Tsirkin" wrote: > >> On Mon, Oct 19, 2015 at 03:44:13PM +0800, Xiao Guangrong wrote: >>> >>> >>> On 10/19/2015 03:39 PM, Michael S. Tsirkin wrote: >>>> On Mon, Oct 19, 2015 at 03:27:21PM +0800, Xiao Guangrong wrote: >>>>>>> + nvdimm_init_memory_state(&pcms->nvdimm_memory, >>>>>>> system_memory, machine, >>>>>>> + TARGET_PAGE_SIZE); >>>>>>> + >>>>>> >>>>>> Shouldn't this be conditional on presence of the nvdimm device? >>>>>> >>>>> >>>>> We will enable hotplug on nvdimm devices in the near future once >>>>> Linux driver is ready. I'd keep it here for future development. >>>> >>>> No, I don't think we should add stuff unconditionally. If not >>>> nvdimm, some other flag should indicate user intends to hotplug >>>> things. >>>> >>> >>> Actually, it is not unconditionally which is called if parameter >>> "-m aaa, maxmem=bbb" (aaa < bbb) is used. It is on the some path of >>> memoy-hotplug initiation. >>> >> >> Right, but that's not the same as nvdimm. >> > > it could be pc-machine property, then it could be turned on like this: > -machine nvdimm_support=on Er, I do not understand why this separate switch is needed and why nvdimm and pc-dimm is different. :( NVDIMM reuses memory-hotplug's framework, such as maxmem, slot, and dimm device, even some of ACPI logic to do hotplug things, etc. Both nvdimm and pc-dimm are built on the same infrastructure.