From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [Qemu-devel] [PATCH v2 06/11] nvdimm acpi: initialize the resource used by NVDIMM ACPI Date: Mon, 15 Feb 2016 11:18:33 +0200 Message-ID: <20160215111705-mutt-send-email-mst@redhat.com> References: <1452624610-46945-1-git-send-email-guangrong.xiao@linux.intel.com> <1452624610-46945-7-git-send-email-guangrong.xiao@linux.intel.com> <20160208120337.44720b0b@nial.brq.redhat.com> <56C01747.3030102@linux.intel.com> <20160215101105.47e9245a@nial.brq.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Xiao Guangrong , 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 To: Igor Mammedov Return-path: Received: from mx1.redhat.com ([209.132.183.28]:46923 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752585AbcBOJSi (ORCPT ); Mon, 15 Feb 2016 04:18:38 -0500 Content-Disposition: inline In-Reply-To: <20160215101105.47e9245a@nial.brq.redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, Feb 15, 2016 at 10:11:05AM +0100, Igor Mammedov wrote: > On Sun, 14 Feb 2016 13:57:27 +0800 > Xiao Guangrong wrote: > > > On 02/08/2016 07:03 PM, Igor Mammedov wrote: > > > On Wed, 13 Jan 2016 02:50:05 +0800 > > > Xiao Guangrong wrote: > > > > > >> 32 bits IO port starting from 0x0a18 in guest is reserved for NVDIMM > > >> ACPI emulation. The table, NVDIMM_DSM_MEM_FILE, will be patched into > > >> NVDIMM ACPI binary code > > >> > > >> OSPM uses this port to tell QEMU the final address of the DSM memory > > >> and notify QEMU to emulate the DSM method > > > Would you need to pass control to QEMU if each NVDIMM had its whole > > > label area MemoryRegion mapped right after its storage MemoryRegion? > > > > > > > No, label data is not mapped into guest's address space and it only > > can be accessed by DSM method indirectly. > Yep, per spec label data should be accessed via _DSM but question > wasn't about it, > Why would one map only 4Kb window and serialize label data > via it if it could be mapped as whole, that way _DMS method will be > much less complicated and there won't be need to add/support a protocol > for its serialization. > Is it ever accessed on data path? If not I prefer the current approach: limit the window used, the serialization protocol seems rather simple. -- MST