From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751385AbdAMJ1f convert rfc822-to-8bit (ORCPT ); Fri, 13 Jan 2017 04:27:35 -0500 Received: from mga14.intel.com ([192.55.52.115]:42669 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751294AbdAMJ1b (ORCPT ); Fri, 13 Jan 2017 04:27:31 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,221,1477983600"; d="scan'208";a="48423182" From: "Li, Liang Z" To: "Michael S. Tsirkin" CC: "kvm@vger.kernel.org" , "virtio-dev@lists.oasis-open.org" , "qemu-devel@nongnu.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "amit.shah@redhat.com" , "Hansen, Dave" , "cornelia.huck@de.ibm.com" , "pbonzini@redhat.com" , "david@redhat.com" , "aarcange@redhat.com" , "dgilbert@redhat.com" , "quintela@redhat.com" Subject: RE: [virtio-dev] Re: [PATCH v6 kernel 2/5] virtio-balloon: define new feature bit and head struct Thread-Topic: [virtio-dev] Re: [PATCH v6 kernel 2/5] virtio-balloon: define new feature bit and head struct Thread-Index: AQHSbQwmAZ/LY8MaHkSLuSWzmOR9iqE2IraQ Date: Fri, 13 Jan 2017 09:24:22 +0000 Message-ID: References: <1482303148-22059-1-git-send-email-liang.z.li@intel.com> <1482303148-22059-3-git-send-email-liang.z.li@intel.com> <20170112185719-mutt-send-email-mst@kernel.org> In-Reply-To: <20170112185719-mutt-send-email-mst@kernel.org> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiYjY5MDc0MmQtOWZhMS00NzA1LWI0MDEtNTVmOTUwZWQ4OTg2IiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6IjN1VWR4aDBXeUI1TlpFUFVZUzRqd0xsNXQ4d3ExVWdJOHpqa3U2UjhLaTQ9In0= x-ctpclassification: CTP_IC x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Wed, Dec 21, 2016 at 02:52:25PM +0800, Liang Li wrote: > > Add a new feature which supports sending the page information with > > range array. The current implementation uses PFNs array, which is not > > very efficient. Using ranges can improve the performance of > > inflating/deflating significantly. > > > > Signed-off-by: Liang Li > > Cc: Michael S. Tsirkin > > Cc: Paolo Bonzini > > Cc: Cornelia Huck > > Cc: Amit Shah > > Cc: Dave Hansen > > Cc: Andrea Arcangeli > > Cc: David Hildenbrand > > --- > > include/uapi/linux/virtio_balloon.h | 12 ++++++++++++ > > 1 file changed, 12 insertions(+) > > > > diff --git a/include/uapi/linux/virtio_balloon.h > > b/include/uapi/linux/virtio_balloon.h > > index 343d7dd..2f850bf 100644 > > --- a/include/uapi/linux/virtio_balloon.h > > +++ b/include/uapi/linux/virtio_balloon.h > > @@ -34,10 +34,14 @@ > > #define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before > reclaiming pages */ > > #define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue > */ > > #define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon > on OOM */ > > +#define VIRTIO_BALLOON_F_PAGE_RANGE 3 /* Send page info > with ranges */ > > > > /* Size of a PFN in the balloon interface. */ #define > > VIRTIO_BALLOON_PFN_SHIFT 12 > > > > +/* Bits width for the length of the pfn range */ > > What does this mean? Couldn't figure it out. > > > +#define VIRTIO_BALLOON_NR_PFN_BITS 12 > > + > > struct virtio_balloon_config { > > /* Number of pages host wants Guest to give up. */ > > __u32 num_pages; > > @@ -82,4 +86,12 @@ struct virtio_balloon_stat { > > __virtio64 val; > > } __attribute__((packed)); > > > > +/* Response header structure */ > > +struct virtio_balloon_resp_hdr { > > + __le64 cmd : 8; /* Distinguish different requests type */ > > + __le64 flag: 8; /* Mark status for a specific request type */ > > + __le64 id : 16; /* Distinguish requests of a specific type */ > > + __le64 data_len: 32; /* Length of the following data, in bytes */ > > This use of __le64 makes no sense. Just use u8/le16/le32 pls. > Got it, will change in the next version. And could help take a look at other parts? as well as the QEMU part. Thanks! Liang