From patchwork Wed Jun 21 12:52:47 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 9801743 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0B2BE60329 for ; Wed, 21 Jun 2017 12:54:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EE70A28545 for ; Wed, 21 Jun 2017 12:54:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E3395285C7; Wed, 21 Jun 2017 12:54:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 649B828545 for ; Wed, 21 Jun 2017 12:54:54 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dNf7x-0005BO-2Z; Wed, 21 Jun 2017 12:52:57 +0000 Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dNf7w-0005B4-Fc for xen-devel@lists.xenproject.org; Wed, 21 Jun 2017 12:52:56 +0000 Received: from [193.109.254.147] by server-7.bemta-6.messagelabs.com id 10/8E-03620-72C6A495; Wed, 21 Jun 2017 12:52:55 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupnkeJIrShJLcpLzFFi42JxWrrBXlc9xyv S4OFfeYvvWyYzOTB6HP5whSWAMYo1My8pvyKBNWNOz2LmggUCFSeu8DUw9vB2MXJySAj4S+w5 1M4CYrMJ6EhMfXqJFcQWEQiXeNx2iqmLkYuDWeAwo0TP/k6wImGBJIljD3exdzFycLAIqEq86 dAFMXkFrCWaD6ZAjJSX2NV2EWwMp4CNxP5Xf9lAbCGgkovntrBA2CoS66fOAovzCghKnJz5BC zOLCAhcfDFC+YJjLyzkKRmIUktYGRaxahRnFpUllqka2iol1SUmZ5RkpuYmaNraGCml5taXJy YnpqTmFSsl5yfu4kRGDgMQLCD8dOygEOMkhxMSqK85d5ekUJ8SfkplRmJxRnxRaU5qcWHGDU4 OAT61qy+wCjFkpefl6okwXs1C6hOsCg1PbUiLTMHGNowpRIcPEoivG4BQGne4oLE3OLMdIjUK UZFKXHeVSB9AiCJjNI8uDZYPF1ilJUS5mUEOkqIpyC1KDezBFX+FaM4B6OSMO8zkCk8mXklcN NfAS1mAlr84ogHyOKSRISUVAMjR8+6s3s138SETs9/Kfhb8YxyUdet9nNX6uK8hBezms5/PMH hjY/qJ4mtnuu21Fx8nvUp+L3mjSSFZ6lMlboaD+ZcmGL0IXXjjBnRp7f923KNrV18Vy7/0ntO uR9iyvd/d3IQEDxfb7VJcWPu/2nef3WUk1bpmyQ9+1Ex5ybDhyerdSNdfTx6lViKMxINtZiLi hMBq2ClRKICAAA= X-Env-Sender: prvs=338cb52eb=Paul.Durrant@citrix.com X-Msg-Ref: server-6.tower-27.messagelabs.com!1498049573!108959718!2 X-Originating-IP: [66.165.176.63] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogNjYuMTY1LjE3Ni42MyA9PiAzMDYwNDg=\n, received_headers: No Received headers X-StarScan-Received: X-StarScan-Version: 9.4.19; banners=-,-,- X-VirusChecked: Checked Received: (qmail 59888 invoked from network); 21 Jun 2017 12:52:55 -0000 Received: from smtp02.citrix.com (HELO SMTP02.CITRIX.COM) (66.165.176.63) by server-6.tower-27.messagelabs.com with RC4-SHA encrypted SMTP; 21 Jun 2017 12:52:55 -0000 X-IronPort-AV: E=Sophos;i="5.39,369,1493683200"; d="scan'208";a="437300029" From: Paul Durrant To: , , Date: Wed, 21 Jun 2017 08:52:47 -0400 Message-ID: <20170621125249.8805-2-paul.durrant@citrix.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170621125249.8805-1-paul.durrant@citrix.com> References: <20170621125249.8805-1-paul.durrant@citrix.com> MIME-Version: 1.0 Cc: Anthony Perard , Kevin Wolf , Paul Durrant , Stefano Stabellini , Max Reitz Subject: [Xen-devel] [PATCH v2 1/3] xen-disk: only advertize feature-persistent if grant copy is not available X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP If grant copy is available then it will always be used in preference to persistent maps. In this case feature-persistent should not be advertized to the frontend, otherwise it may needlessly copy data into persistently granted buffers. Signed-off-by: Paul Durrant Reviewed-by: Stefano Stabellini --- Cc: Stefano Stabellini Cc: Anthony Perard Cc: Kevin Wolf Cc: Max Reitz --- hw/block/xen_disk.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index 3a22805fbc..9b06e3aa81 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -1023,11 +1023,18 @@ static int blk_init(struct XenDevice *xendev) blkdev->file_blk = BLOCK_SIZE; + blkdev->feature_grant_copy = + (xengnttab_grant_copy(blkdev->xendev.gnttabdev, 0, NULL) == 0); + + xen_pv_printf(&blkdev->xendev, 3, "grant copy operation %s\n", + blkdev->feature_grant_copy ? "enabled" : "disabled"); + /* fill info * blk_connect supplies sector-size and sectors */ xenstore_write_be_int(&blkdev->xendev, "feature-flush-cache", 1); - xenstore_write_be_int(&blkdev->xendev, "feature-persistent", 1); + xenstore_write_be_int(&blkdev->xendev, "feature-persistent", + !blkdev->feature_grant_copy); xenstore_write_be_int(&blkdev->xendev, "info", info); blk_parse_discard(blkdev); @@ -1202,12 +1209,6 @@ static int blk_connect(struct XenDevice *xendev) xen_be_bind_evtchn(&blkdev->xendev); - blkdev->feature_grant_copy = - (xengnttab_grant_copy(blkdev->xendev.gnttabdev, 0, NULL) == 0); - - xen_pv_printf(&blkdev->xendev, 3, "grant copy operation %s\n", - blkdev->feature_grant_copy ? "enabled" : "disabled"); - xen_pv_printf(&blkdev->xendev, 1, "ok: proto %s, ring-ref %d, " "remote port %d, local port %d\n", blkdev->xendev.protocol, blkdev->ring_ref,