From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal Novotny Subject: Re: [PATCH] qemu-xen-3.4-testing: Fix read-only image file handling Date: Mon, 07 Jun 2010 15:10:24 +0200 Message-ID: <4C0CEFC0.5040506@redhat.com> References: <4C07B678.3020304@redhat.com> <4C07B853.3000307@redhat.com> <4C08C96F.2080400@redhat.com> <20100604104250.GL17817@reaktio.net> <4C0CD631.4030006@redhat.com> <20100607114538.GC17817@reaktio.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20100607114538.GC17817@reaktio.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On 06/07/2010 01:45 PM, Pasi K=E4rkk=E4inen wrote: > On Mon, Jun 07, 2010 at 01:21:21PM +0200, Michal Novotny wrote: > =20 >> 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=3DLABEL=3D/rhel2 rhgb quiet= selinux=3D0 >> module /initrd-2.6.31.13.img >> >> Mount is having `xenfs on /proc/xen type xenfs (rw)`. Any guess what m= ay >> be going wrong? >> >> =20 > > Do you have xen-evtchn driver loaded? > > > -- Pasi > > =20 Well, no, and doesn't seem to be installed/probed: # modprobe xen-evtchn # lsmod | grep xen-evtchn # So there's the problem :( Michal > =20 >> Thanks, >> Michal >> >> On 06/04/2010 12:42 PM, Pasi K=E4rkk=E4inen wrote: >> =20 >>> On Fri, Jun 04, 2010 at 11:37:51AM +0200, Michal Novotny wrote: >>> >>> =20 >>>> 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 workin= g >>>> for xen-4.1 unstable as well, unfortunately I was not able to boot P= VOPS >>>> kernel since it always ends up in kernel panic, maybe the missing >>>> drivers or something like that. >>>> >>>> >>>> =20 >>> 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 "troubleshoot= ing" 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=3Dy >>> CONFIG_SYSFS_DEPRECATED_V2=3Dy >>> >>> Also atm I think you need CONFIG_XEN_XENBUS_FRONTEND=3Dy in the .conf= ig >>> because of the recently added pv-on-hvm drivers (you'll get build fai= lure without that option), >>> so you need XEN_PCIDEV_FRONTEND XEN_BLKDEV_FRONTEND or XEN_NETDEV_FRO= NTEND or XEN_FBDEV_FRONTEND needs to be =3Dy. >>> >>> -- Pasi >>> >>> >>> >>> =20 >>>> On 06/03/2010 04:12 PM, Michal Novotny wrote: >>>> >>>> =20 >>>>> Oh, just one more thing that should be mentioned: >>>>> >>>>> When you want to mount an image that is set as read-only in the dom= ain >>>>> configuration file but you omit to set mode to read-only it results >>>>> into I/O errors when processing the requests. Remounting as read-on= ly >>>>> 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 DeviceFaul= t >>>>> errors since mounting the device read-write (default setting) write= s >>>>> some data onto a disk at the mount-time. >>>>> >>>>> Michal >>>>> >>>>> On 06/03/2010 04:04 PM, Michal Novotny wrote: >>>>> >>>>> =20 >>>>>> [Well, I did send an e-mail to the list using git but it's not her= e >>>>>> 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_Comma= nd >>>>>> >>>>>> 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 >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Xen-devel mailing list >>>>>> Xen-devel@lists.xensource.com >>>>>> http://lists.xensource.com/xen-devel >>>>>> >>>>>> =20 >>>>> >>>>> =20 >>>> --=20 >>>> Michal Novotny, RHCE >>>> Virtualization Team (xen userspace), Red Hat >>>> >>>> >>>> _______________________________________________ >>>> Xen-devel mailing list >>>> Xen-devel@lists.xensource.com >>>> http://lists.xensource.com/xen-devel >>>> >>>> =20 >> >> --=20 >> Michal Novotny, RHCE >> Virtualization Team (xen userspace), Red Hat >> >> =20 > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel > =20 --=20 Michal Novotny, RHCE Virtualization Team (xen userspace), Red Hat