From patchwork Wed Dec 23 15:21:25 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avishay Traeger1 X-Patchwork-Id: 41674 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 52A3CB7BE7 for ; Thu, 24 Dec 2009 02:22:14 +1100 (EST) Received: from localhost ([127.0.0.1]:41445 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NNT2R-0007pq-GL for incoming@patchwork.ozlabs.org; Wed, 23 Dec 2009 10:22:11 -0500 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NNT1o-0007kz-79 for qemu-devel@nongnu.org; Wed, 23 Dec 2009 10:21:32 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NNT1j-0007jb-Va for qemu-devel@nongnu.org; Wed, 23 Dec 2009 10:21:31 -0500 Received: from [199.232.76.173] (port=35562 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NNT1j-0007jY-R3 for qemu-devel@nongnu.org; Wed, 23 Dec 2009 10:21:27 -0500 Received: from mtagate4.de.ibm.com ([195.212.17.164]:59260) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NNT1j-0000Jy-Cl for qemu-devel@nongnu.org; Wed, 23 Dec 2009 10:21:27 -0500 Received: from d12nrmr1507.megacenter.de.ibm.com (d12nrmr1507.megacenter.de.ibm.com [9.149.167.1]) by mtagate4.de.ibm.com (8.13.1/8.13.1) with ESMTP id nBNFLPpD030693 for ; Wed, 23 Dec 2009 15:21:25 GMT Received: from d12av06.megacenter.de.ibm.com (d12av06.megacenter.de.ibm.com [9.149.165.230]) by d12nrmr1507.megacenter.de.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id nBNFLPXX1827042 for ; Wed, 23 Dec 2009 16:21:25 +0100 Received: from d12av06.megacenter.de.ibm.com (loopback [127.0.0.1]) by d12av06.megacenter.de.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id nBNFLPdE010470 for ; Wed, 23 Dec 2009 16:21:25 +0100 Received: from d12mc102.megacenter.de.ibm.com (d12mc102.megacenter.de.ibm.com [9.149.167.114]) by d12av06.megacenter.de.ibm.com (8.14.3/8.13.1/NCO v10.0 AVin) with ESMTP id nBNFLPGR010467; Wed, 23 Dec 2009 16:21:25 +0100 X-KeepSent: 67D6809E:115A2813-C2257695:0053288C; type=4; name=$KeepSent To: kvm@vger.kernel.org, qemu-devel@nongnu.org X-Mailer: Lotus Notes Release 8.0.1 February 07, 2008 Message-ID: From: Avishay Traeger1 Date: Wed, 23 Dec 2009 17:21:25 +0200 X-MIMETrack: Serialize by Router on D12MC102/12/M/IBM(Release 8.5|December 05, 2008) at 23/12/2009 17:21:25 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) Cc: Anthony Liguori , Rusty Russell Subject: [Qemu-devel] [PATCH 1/2] virtio-blk: add max sectors feature (virtio_blk driver) X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This is a revised patch that allows the guest and host to negotiate the maximum number of total sectors in an I/O. This feature has already been added by Rusty to the virtio spec. Please CC me on replies, as I am not subscribed. Thanks, Avishay Signed-off-by: Avishay Traeger diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 51042f0..e68ea8a 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -351,8 +351,14 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) /* No need to bounce any requests */ blk_queue_bounce_limit(vblk->disk->queue, BLK_BOUNCE_ANY); - /* No real sector limit. */ - blk_queue_max_sectors(vblk->disk->queue, -1U); + /* Host can optionally specify maximum total sectors in an I/O. */ + err = virtio_config_val(vdev, VIRTIO_BLK_F_SECTOR_MAX, + offsetof(struct virtio_blk_config, sectors_max), + &v); + if (!err) + blk_queue_max_sectors(vblk->disk->queue, v); + else + blk_queue_max_sectors(vblk->disk->queue, -1U); /* Host can optionally specify maximum segment size and number of * segments. */ @@ -412,7 +418,7 @@ static struct virtio_device_id id_table[] = { static unsigned int features[] = { VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, - VIRTIO_BLK_F_SCSI, VIRTIO_BLK_F_FLUSH + VIRTIO_BLK_F_SCSI, VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_SECTOR_MAX }; /* diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h index fd294c5..2536d74 100644 --- a/include/linux/virtio_blk.h +++ b/include/linux/virtio_blk.h @@ -15,6 +15,7 @@ #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/ #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ #define VIRTIO_BLK_F_FLUSH 9 /* Cache flush command support */ +#define VIRTIO_BLK_F_SECTOR_MAX 10 /* Maximum total sectors in an I/O */ struct virtio_blk_config { /* The capacity (in 512-byte sectors). */ @@ -31,6 +32,7 @@ struct virtio_blk_config { } geometry; /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ __u32 blk_size; + __u32 sectors_max; } __attribute__((packed)); /*