From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41428) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YEIro-0005lY-Es for qemu-devel@nongnu.org; Thu, 22 Jan 2015 09:36:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YEIrh-0004uX-Gk for qemu-devel@nongnu.org; Thu, 22 Jan 2015 09:36:16 -0500 Received: from e06smtp15.uk.ibm.com ([195.75.94.111]:49210) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YEIrh-0004uC-83 for qemu-devel@nongnu.org; Thu, 22 Jan 2015 09:36:09 -0500 Received: from /spool/local by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 22 Jan 2015 14:36:08 -0000 Received: from b06cxnps3075.portsmouth.uk.ibm.com (d06relay10.portsmouth.uk.ibm.com [9.149.109.195]) by d06dlp03.portsmouth.uk.ibm.com (Postfix) with ESMTP id EC4F11B08061 for ; Thu, 22 Jan 2015 14:36:07 +0000 (GMT) Received: from d06av04.portsmouth.uk.ibm.com (d06av04.portsmouth.uk.ibm.com [9.149.37.216]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t0MEa6F156623202 for ; Thu, 22 Jan 2015 14:36:06 GMT Received: from d06av04.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av04.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t0MEa4EB031800 for ; Thu, 22 Jan 2015 07:36:05 -0700 Message-ID: <54C10AD3.6090804@de.ibm.com> Date: Thu, 22 Jan 2015 15:36:03 +0100 From: Christian Borntraeger MIME-Version: 1.0 References: <1421678101-44779-1-git-send-email-tumanova@linux.vnet.ibm.com> In-Reply-To: <1421678101-44779-1-git-send-email-tumanova@linux.vnet.ibm.com> Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v6 0/5] Geometry and blocksize detection for backing devices. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ekaterina Tumanova , Public KVM Mailing List Cc: kwolf@redhat.com, thuth@linux.vnet.ibm.com, armbru@redhat.com, mihajlov@linux.vnet.ibm.com, dahi@linux.vnet.ibm.com, stefanha@redhat.com, cornelia.huck@de.ibm.com, pbonzini@redhat.com Am 19.01.2015 um 15:34 schrieb Ekaterina Tumanova: > Updates v5 -> v6: > > Minor Updates according the last review from Stefan Hajnoczi: > 1. Do not change the flow of code, factored out of raw_probe_alignment. > 2. added #ifdef __linux__ in 2 places of raw-posix.c, mentioned by reviewer. > 3. adjusted the comment hdev_probe_geometry according suggestment. > 4. use bdrv_nb_sectors(bs) instead of bs->total_sectors. > 5. do not discard error blk_probe_blocksizes(). now has rc. > 6. put the 512-byte default blocksize value in blkconf_blocksizes. > 7. drop the default parameter from the DEFINE_PROP_BLOCKSIZE() macro. > > Thanks, > Kate. > > --------------------------------------------------------------- > Patchset Description (didn't change): > > Proper geometry and blocksize information is vital for support of > DASD/ECKD drives in Linux guests. Otherwise things will fail in > certain cases. > > The existing geometry and blocksize qemu defaults have no sense > for DASD drives (hd_geometry_guess detection and 512 for sizes). > Setting this information manually in XML file is far from user-friendly, > as the admin has to manually look up the properties of the > host disks and then modify the guest definition accordingly. > > Since Linux uses DASDs as normal block devices, we actually > want to use virtio-blk to pass those to KVM guests. > > In order to avoid any change in behavior of other drives, the DASD > special casing was advised. We call ioctl BIODASDINFO2 on the block > device, which will only succeed if the device is really a DASD. > > In order to retrieve the underlying device geometry and blocksizes > a new block-backend functions and underlying driver functions were > introduced (blk_probe_blocksizes anf blk_probe_geometry wrappers > and corresponding bdrv_xxxxxx functions). > > As for now only "host_device" driver received new detection methods. > For "raw" we call childs method as usual. In future one may update > other drivers to add some other detection heuristics. > > If the host_device appears to be a DASD, the driver functions > (hdev_probe_blocksizes and hdev_probe_geometry) will call certain > ioctls in order to detect geometry and blocksizes of the underlying device. > if probing failed bdrv_probe_blocksizes caller will set defaults, > and bdrv_probe_geometry will fail to allow fallback to old detection logic. > > The front-end (BlockConf API) was updated: > 1. a new blkconf_blocksizes function was added. It doesn't > change user-defined blocksize values. If properties are unset, it will > set values, returned by blk_probe_backend. In order to allow this logic, > blocksize properties were initialized with 0. (driver will return 512 if > backing device probing didn't succeed or if driver method is not defined). > 2. hd_geometry guess was changed to firstly try to retrieve values via > blk_probe_geometry and if it fails, fallback to the old logic. > > Ekaterina Tumanova (5): > block: add bdrv functions for geometry and blocksize > raw-posix: Factor block size detection out of raw_probe_alignment() > block: Add driver methods to probe blocksizes and geometry > block-backend: Add wrappers for blocksizes and geometry probing > BlockConf: Call backend functions to detect geometry and blocksizes > > block.c | 36 ++++++++++ > block/block-backend.c | 10 +++ > block/raw-posix.c | 154 ++++++++++++++++++++++++++++++++++++----- > block/raw_bsd.c | 12 ++++ > hw/block/block.c | 20 ++++++ > hw/block/hd-geometry.c | 10 ++- > hw/block/nvme.c | 1 + > hw/block/virtio-blk.c | 1 + > hw/core/qdev-properties.c | 3 +- > hw/ide/qdev.c | 1 + > hw/scsi/scsi-disk.c | 1 + > hw/usb/dev-storage.c | 1 + > include/block/block.h | 13 ++++ > include/block/block_int.h | 15 ++++ > include/hw/block/block.h | 5 +- > include/hw/qdev-properties.h | 4 +- > include/sysemu/block-backend.h | 2 + > 17 files changed, 267 insertions(+), 22 deletions(-) > Just gave version 6 a try. My dasd is recognizes as it should be. So Tested-by: Christian Borntraeger