From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34729) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e42VW-0005Ew-8j for qemu-devel@nongnu.org; Mon, 16 Oct 2017 06:20:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e42VT-0002L9-5T for qemu-devel@nongnu.org; Mon, 16 Oct 2017 06:20:26 -0400 Received: from mail-io0-x242.google.com ([2607:f8b0:4001:c06::242]:47089) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1e42VS-0002KY-R9 for qemu-devel@nongnu.org; Mon, 16 Oct 2017 06:20:23 -0400 Received: by mail-io0-x242.google.com with SMTP id 101so15491580ioj.3 for ; Mon, 16 Oct 2017 03:20:21 -0700 (PDT) References: <1508144183-30844-1-git-send-email-yang.zhong@intel.com> From: Xiao Guangrong Message-ID: Date: Mon, 16 Oct 2017 18:20:32 +0800 MIME-Version: 1.0 In-Reply-To: <1508144183-30844-1-git-send-email-yang.zhong@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/2] add "nopin" option in the memory-backend-file List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yang Zhong , qemu-devel@nongnu.org Cc: ehabkost@redhat.com, alex.williamson@redhat.com, pbonzini@redhat.com, anthony.xu@intel.com On 10/16/2017 04:56 PM, Yang Zhong wrote: > Qemu does not need pin NVDIMM memory for VFIO device during VFIO > hotplug, what's more, if there is no NVDIMM hw in the test machine, > the VFIO hotplug operation will need at least 10 minutes to pin RAM > as the NVDIMM, this time is not accepted. So we add "nopin=on" option > in the memory-backed-file, which can avoid to pin RAM memory for NVDIMM. No. memory-backed-file does not dedicate for nvdimm only, it can be mapped as normal memory as well. Rather more, this is no way to stop guest to use it as DMA.