Xen project Mailing List

Re: [Xen-devel] [PATCH] qemu-xen-3.4-testing: Fix read-only image file handling

To: Michal Novotny <minovotn@xxxxxxxxxx>

From: Pasi Kärkkäinen <pasik@xxxxxx>

Date: Mon, 7 Jun 2010 16:19:36 +0300

Cc: xen-devel@xxxxxxxxxxxxxxxxxxx, Keir Fraser <keir.fraser@xxxxxxxxxxxxx>

Delivery-date: Mon, 07 Jun 2010 06:20:32 -0700

List-id: Xen developer discussion <xen-devel.lists.xensource.com>

On Mon, Jun 07, 2010 at 03:14:40PM +0200, Michal Novotny wrote: > On 06/07/2010 03:10 PM, Michal Novotny wrote: >> On 06/07/2010 01:45 PM, Pasi Kärkkäinen wrote: >>> On Mon, Jun 07, 2010 at 01:21:21PM +0200, Michal Novotny wrote: >>>> Well, I'm still having some tools issues, mainly: >>>> >>>> Error: (111, 'Connection refused') >>>> >>>> Any guess what may be going wrong? Booted grub entry: >>>> >>>> title Red Hat Enterprise Linux Server (2.6.31.13-xen HV, nolog) >>>> root (hd1,6) >>>> kernel /xen-4.1-unstable.gz >>>> module /vmlinuz-2.6.31.13 ro root=LABEL=/rhel2 rhgb quiet >>>> selinux=0 >>>> module /initrd-2.6.31.13.img >>>> >>>> Mount is having `xenfs on /proc/xen type xenfs (rw)`. Any guess >>>> what may >>>> be going wrong? >>>> >>> >>> Do you have xen-evtchn driver loaded? >>> >>> >>> -- Pasi >>> >> >> Well, no, and doesn't seem to be installed/probed: >> >> # modprobe xen-evtchn >> # lsmod | grep xen-evtchn >> # >> >> So there's the problem :( >> >> Michal > > Oh, I'm taking this back since I found out the module is not xen-evtchn > but xen_evtchn. So yeah, I'm having it loaded in the memory now. > However, when I do `service xend restart` the same error is here: > > [2010-06-07 17:14:09 5635] INFO (SrvDaemon:227) Xend stopped due to > signal 15. > [2010-06-07 17:14:09 6295] INFO (SrvDaemon:332) Xend Daemon started > [2010-06-07 17:14:09 6295] INFO (SrvDaemon:336) Xend changeset: Thu May > 20 17:22:15 2010 +0100 21442:a7fcf2e35d32. > [2010-06-07 17:14:09 6295] DEBUG (tcp:96) Listening on :8002 > [2010-06-07 17:14:09 6295] INFO (XendNetwork:114) Not recreating missing > unmanaged network eth0 > [2010-06-07 17:14:09 6295] INFO (XendNetwork:114) Not recreating missing > unmanaged network eth2 > [2010-06-07 17:14:09 6295] INFO (XendNetwork:114) Not recreating missing > unmanaged network br0 > [2010-06-07 17:14:09 6295] INFO (XendNetwork:114) Not recreating missing > unmanaged network xenbr0 > [2010-06-07 17:14:10 6295] DEBUG (XendCPUPool:747) recreate_active_pools > [2010-06-07 17:14:10 6295] ERROR (SrvDaemon:349) Exception starting xend > ((111, 'Connection refused')) > Traceback (most recent call last): > File > "/usr/lib64/python2.4/site-packages/xen/xend/server/SrvDaemon.py", line > 341, in run > servers = SrvServer.create() > File > "/usr/lib64/python2.4/site-packages/xen/xend/server/SrvServer.py", line > 258, in create > root.putChild('xend', SrvRoot()) > File "/usr/lib64/python2.4/site-packages/xen/xend/server/SrvRoot.py", > line 40, in __init__ > self.get(name) > File "/usr/lib64/python2.4/site-packages/xen/web/SrvDir.py", line 84, > in get > val = val.getobj() > File "/usr/lib64/python2.4/site-packages/xen/web/SrvDir.py", line 52, > in getobj > self.obj = klassobj() > File "/usr/lib64/python2.4/site-packages/xen/xend/server/SrvNode.py", > line 30, in __init__ > self.xn = XendNode.instance() > File "/usr/lib64/python2.4/site-packages/xen/xend/XendNode.py", line > 1176, in instance > inst = XendNode() > File "/usr/lib64/python2.4/site-packages/xen/xend/XendNode.py", line > 163, in __init__ > self._init_cpu_pools() > File "/usr/lib64/python2.4/site-packages/xen/xend/XendNode.py", line > 377, in _init_cpu_pools > XendCPUPool.recreate_active_pools() > File "/usr/lib64/python2.4/site-packages/xen/xend/XendCPUPool.py", > line 754, in recreate_active_pools > uuid = xstransact.Read(path, 'uuid') > File > "/usr/lib64/python2.4/site-packages/xen/xend/xenstore/xstransact.py", > line 307, in Read > return complete(path, lambda t: t.read(*args)) > File > "/usr/lib64/python2.4/site-packages/xen/xend/xenstore/xstransact.py", > line 361, in complete > t = xstransact(path) > File > "/usr/lib64/python2.4/site-packages/xen/xend/xenstore/xstransact.py", > line 29, in __init__ > self.transaction = xshandle().transaction_start() > File "/usr/lib64/python2.4/site-packages/xen/xend/xenstore/xsutil.py", > line 18, in xshandle > xs_handle = xen.lowlevel.xs.xs() > Error: (111, 'Connection refused') > > Any ideas? > Is xenstore running? Are there files in /proc/xen ? -- Pasi > Michal > >> >>>> Thanks, >>>> Michal >>>> >>>> On 06/04/2010 12:42 PM, Pasi Kärkkäinen wrote: >>>>> On Fri, Jun 04, 2010 at 11:37:51AM +0200, Michal Novotny wrote: >>>>> >>>>>> Oh, one more thing I've discovered now. Since the codebase for >>>>>> qemu-xen-unstable is looking the same like for >>>>>> qemu-xen-3.4-testing and >>>>>> the patch is applicable without any modifications it could be working >>>>>> for xen-4.1 unstable as well, unfortunately I was not able to >>>>>> boot PVOPS >>>>>> kernel since it always ends up in kernel panic, maybe the missing >>>>>> drivers or something like that. >>>>>> >>>>>> >>>>> What kernel version? Did you use xen/stable-2.6.32.x branch from >>>>> xen.git? >>>>> >>>>> See my example .config files from: >>>>> http://wiki.xensource.com/xenwiki/XenParavirtOps in the >>>>> "troubleshooting" section. >>>>> >>>>> Works on F12/F13 dom0's. >>>>> >>>>> For el5 dom0 you might need these: >>>>> http://wiki.xensource.com/xenwiki/2.6.18-to-2.6.31-and-higher >>>>> >>>>> aka >>>>> CONFIG_SYSFS_DEPRECATED=y >>>>> CONFIG_SYSFS_DEPRECATED_V2=y >>>>> >>>>> Also atm I think you need CONFIG_XEN_XENBUS_FRONTEND=y in the .config >>>>> because of the recently added pv-on-hvm drivers (you'll get build >>>>> failure without that option), >>>>> so you need XEN_PCIDEV_FRONTEND XEN_BLKDEV_FRONTEND or >>>>> XEN_NETDEV_FRONTEND or XEN_FBDEV_FRONTEND needs to be =y. >>>>> >>>>> -- Pasi >>>>> >>>>> >>>>> >>>>>> On 06/03/2010 04:12 PM, Michal Novotny wrote: >>>>>> >>>>>>> Oh, just one more thing that should be mentioned: >>>>>>> >>>>>>> When you want to mount an image that is set as read-only in >>>>>>> the domain >>>>>>> configuration file but you omit to set mode to read-only it results >>>>>>> into I/O errors when processing the requests. Remounting as >>>>>>> read-only >>>>>>> or unmounting and remounting using the `mount /dev/* >>>>>>> /path/to/mount -o >>>>>>> ro` shall do the mounting the correct way, i.e. with no I/O >>>>>>> errors, so >>>>>>> make sure you mount those disks as read-only otherwise you can be >>>>>>> getting errors like: >>>>>>> >>>>>>> end_request: I/O error, dev hdb, sector 52 >>>>>>> >>>>>>> Buffer I/O error on device hdb1, logical block 1 >>>>>>> >>>>>>> lost page write due to I/O error on hdb1 >>>>>>> >>>>>>> >>>>>>> and for IDE devices you'll be getting several additional DeviceFault >>>>>>> errors since mounting the device read-write (default setting) writes >>>>>>> some data onto a disk at the mount-time. >>>>>>> >>>>>>> Michal >>>>>>> >>>>>>> On 06/03/2010 04:04 PM, Michal Novotny wrote: >>>>>>> >>>>>>>> [Well, I did send an e-mail to the list using git but it's not here >>>>>>>> so I'm forwarding the e-mail to the list for sure:] >>>>>>>> >>>>>>>> Hi, >>>>>>>> this is the patch for qemu-xen-3.4-testing to fix the read-only >>>>>>>> image file handling since the image file was always treated as >>>>>>>> read-write which means that all the HVM guests were able to >>>>>>>> write to all the disk images available in domain configuration >>>>>>>> file no matter what the mode of the image was defined. This >>>>>>>> patch fixes this functionality to honor the O_RDONLY in the >>>>>>>> BDRV_O_ACCESS flag in block.c and also fixes the IDE and SCSI >>>>>>>> interfaces that uses it. >>>>>>>> >>>>>>>> It's been tested on RHEL-5 with xen-3.4-testing version of >>>>>>>> upstream xen with xen-3.4-testing qemu implementation. >>>>>>>> >>>>>>>> For SCSI devices the DATA PROTECT request sense has been added >>>>>>>> as found at: >>>>>>>> http://en.wikipedia.org/wiki/SCSI_Request_Sense_Command >>>>>>>> >>>>>>>> file no matter what the mode of the image was defined. This >>>>>>>> patch fixes this functionality to honor the O_RDONLY in the >>>>>>>> BDRV_O_ACCESS flag in block.c and also fixes the IDE and SCSI >>>>>>>> interfaces that uses it. >>>>>>>> >>>>>>>> It's been tested on RHEL-5 with xen-3.4-testing version of >>>>>>>> Michal >>>>>>>> >>>>>>>> Signed-off-by: Michal Novotny<minovotn@xxxxxxxxxx> >>>>>>>> >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> Xen-devel mailing list >>>>>>>> Xen-devel@xxxxxxxxxxxxxxxxxxx >>>>>>>> http://lists.xensource.com/xen-devel >>>>>>>> >>>>>>> >>>>>> -- >>>>>> Michal Novotny<minovotn@xxxxxxxxxx>, RHCE >>>>>> Virtualization Team (xen userspace), Red Hat >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Xen-devel mailing list >>>>>> Xen-devel@xxxxxxxxxxxxxxxxxxx >>>>>> http://lists.xensource.com/xen-devel >>>>>> >>>> >>>> -- >>>> Michal Novotny<minovotn@xxxxxxxxxx>, RHCE >>>> Virtualization Team (xen userspace), Red Hat >>>> >>> _______________________________________________ >>> Xen-devel mailing list >>> Xen-devel@xxxxxxxxxxxxxxxxxxx >>> http://lists.xensource.com/xen-devel >> >> > > > -- > Michal Novotny<minovotn@xxxxxxxxxx>, RHCE > Virtualization Team (xen userspace), Red Hat > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel

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