From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46683) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c1AZp-0005hv-6C for qemu-devel@nongnu.org; Mon, 31 Oct 2016 07:16:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c1AZj-0004yp-5l for qemu-devel@nongnu.org; Mon, 31 Oct 2016 07:16:29 -0400 Received: from mga04.intel.com ([192.55.52.120]:8307) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1c1AZi-0004yY-T9 for qemu-devel@nongnu.org; Mon, 31 Oct 2016 07:16:23 -0400 References: <1477850917-1214-1-git-send-email-mst@redhat.com> <1477850917-1214-31-git-send-email-mst@redhat.com> <20161031102032.0eb037b3@nial.brq.redhat.com> <6e873b38-715d-c9e5-9750-adaa88a00ba1@linux.intel.com> <20161031115644.71ca634a@nial.brq.redhat.com> From: Xiao Guangrong Message-ID: <040a2450-a854-3e97-15b3-621c571debb3@linux.intel.com> Date: Mon, 31 Oct 2016 19:09:07 +0800 MIME-Version: 1.0 In-Reply-To: <20161031115644.71ca634a@nial.brq.redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PULL 30/47] acpi nvdimm: fix device physical address base List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: "Michael S. Tsirkin" , qemu-devel@nongnu.org, Peter Maydell On 10/31/2016 06:56 PM, Igor Mammedov wrote: > On Mon, 31 Oct 2016 17:23:31 +0800 > Xiao Guangrong wrote: > >> On 10/31/2016 05:20 PM, Igor Mammedov wrote: >>> On Sun, 30 Oct 2016 23:24:46 +0200 >>> "Michael S. Tsirkin" wrote: >>> >>>> From: Xiao Guangrong >>>> >>>> According to ACPI 6.0 spec, "Memory Device Physical Address >>>> Region Base" in memdev is defined as "This field provides the >>>> Device Physical Address base of the region". This field should >>>> be zero in our case >>> I'm not sure that it should be a zero, >>> care to point source which tells that it should be zero? >> >> The spec says that this is the Device Physical Address, so that >> it is the device internal address, it should be zero as we do not >> reserve any thing in device internal and we do not have no memory >> interleave. > spec says (ACPI 6.1: 5.2.25.3 NVDIMM Region Mapping Structure): > "NVDIMM Physical Address Region Base": > "The base physical address within the NVDIMM of the NVDIMM region." > > and nothing more than that so it's hard to come to conclusion that > it's internal address nor it is offset as you treat it here > (structure has 'Region Offset' for that). I think it is clear as the spec says "_within_ the NVDIMM", it is even more clear than ACPI 6.0 (5.2.25.2 Memory Device to System Physical Address Range Mapping Structure), in that, it says: "In bytes. This field provides the Device Physical Address base of the region." In the namespace spec (http://pmem.io/documents/NVDIMM_Namespace_Spec.pdf), the explanation to DPA in page 9: "DIMM Physical Address: A memory address from a DIMM’s perspective, that is, the offset into the DIMM’s memory, starting with DPA zero as the lowest addressable byte of the DIMM.