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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 97FA7C46475 for ; Thu, 25 Oct 2018 10:14:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 564562082E for ; Thu, 25 Oct 2018 10:14:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 564562082E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727418AbeJYSqX (ORCPT ); Thu, 25 Oct 2018 14:46:23 -0400 Received: from mga11.intel.com ([192.55.52.93]:47195 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726803AbeJYSqX (ORCPT ); Thu, 25 Oct 2018 14:46:23 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Oct 2018 03:14:19 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,424,1534834800"; d="scan'208";a="94902601" Received: from unknown (HELO [10.239.13.114]) ([10.239.13.114]) by orsmga003.jf.intel.com with ESMTP; 25 Oct 2018 03:14:15 -0700 Message-ID: <5BD1988D.7010606@intel.com> Date: Thu, 25 Oct 2018 18:18:53 +0800 From: Wei Wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: "Michael S. Tsirkin" CC: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mhocko@kernel.org, akpm@linux-foundation.org, dgilbert@redhat.com, torvalds@linux-foundation.org, pbonzini@redhat.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, riel@redhat.com, peterx@redhat.com, quintela@redhat.com Subject: Re: [PATCH v37 0/3] Virtio-balloon: support free page reporting References: <1535333539-32420-1-git-send-email-wei.w.wang@intel.com> <20181024205759-mutt-send-email-mst@kernel.org> In-Reply-To: <20181024205759-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/25/2018 08:58 AM, Michael S. Tsirkin wrote: > On Mon, Aug 27, 2018 at 09:32:16AM +0800, Wei Wang wrote: >> The new feature, VIRTIO_BALLOON_F_FREE_PAGE_HINT, implemented by this >> series enables the virtio-balloon driver to report hints of guest free >> pages to host. It can be used to accelerate virtual machine (VM) live >> migration. Here is an introduction of this usage: >> >> Live migration needs to transfer the VM's memory from the source machine >> to the destination round by round. For the 1st round, all the VM's memory >> is transferred. From the 2nd round, only the pieces of memory that were >> written by the guest (after the 1st round) are transferred. One method >> that is popularly used by the hypervisor to track which part of memory is >> written is to have the hypervisor write-protect all the guest memory. >> >> This feature enables the optimization by skipping the transfer of guest >> free pages during VM live migration. It is not concerned that the memory >> pages are used after they are given to the hypervisor as a hint of the >> free pages, because they will be tracked by the hypervisor and transferred >> in the subsequent round if they are used and written. > OK so it will be in linux-next. Now can I trouble you for a virtio spec > patch with the description please? No problem, I'll start to patch the spec. Thanks! Best, Wei