Re: [Xen-users] baremetal to PV troubles

[Dylan Martin <dmartin@xxxxxxxxxxxx>]

Thanks for answering!  I have loads more questions...

Okay, I think I understand.  I'd use the 64 bit kernel & modules but
the 32 bit libs, right?  

How does the 64 bit kernel know the userland is 32 bit?  Won't it try
and find the 64 bit libs and freak out?  

Does it use memory like a 64 bit machine?  Is there any reason to run
a 32 bit domU in a 64 bit dom0?

Thanks!
-Dylan

> 32 bit USERSPACE is fine, but for paravirtual, the KERNELS must match. You 
> can go do the 32 bit install somewhere and tar/rsync/copy/whatever the 
> files accross and the install should work somewhere, but you can't use the 
> 32 bit kernel from that install.
> 
> At least "kernels must match" for PV has been the way things are in the 
> past, maybe things have changed now. I haven't used 3.1 yet.
> 
> -Tom
> 
> On Thu, 12 Jul 2007, Dylan Martin wrote:
> 
> >Yeah, you know I had that thought this morning as I was waking up.
> >
> >Basically, any time I tried to boot with a 32 bit kernel & initrd, it
> >panicked.  I tried with my own kernel & initrd and with the i386
> >Fedora 7 xen install kernel & initrd and got crashes every time.  When
> >I tried the x86_64 Fedora 7 xen install initrd and kernel, it worked
> >fine.   So, why is that?  It seems to be croaking on the xenblk module
> >specifically.
> >
> >Does anyone know if there are other xm config settings that you must
> >put in place to make a 32 bit linux pv domU run on a 64 bit linux
> >dom0?  That's my best theory as of this moment.
> >
> >-Dylan
> >
> >>Hello,
> >>
> >>    Should not 32bit linux DomU also work under 64bit Xen? I thought it
> >>is possible...
> >>
> >>    With regards,
> >>
> >>            Artur
> >>
> >>-----Original Message-----
> >>From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
> >>[mailto:xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Dylan Martin
> >>Sent: Thursday, July 12, 2007 2:09 AM
> >>To: Xen Users
> >>Subject: Re: [Xen-users] baremetal to PV troubles
> >>
> >>Oy!  I think I figured it out.
> >>
> >>Xen box     = 64bit
> >>Tar archive = 32bit
> >>Me                  = ouch!
> >>
> >>>Hi.
> >>>
> >>>I've got linux system running on it's own box that I want to convert to a
> >>>PV domU in xen.  The kernel panics after adding the xenblk module.
> >>>
> >>> Here's what I've done:
> >>>
> >>>1) tar'ed up the running non-xen system and copy to dom0
> >>>2) created new LV on dom0
> >>>3) fdisked, kpartx -a , pvcreate, vgcreate, lvcreate, mount etc...
> >>>   that LV into a normal file hierarchy.
> >>>4) untar'ed the tar file from step 1 onto my new file heirarchy.
> >>>5) chroot to new file hierarchy
> >>>6) fiddle with /dev, /etc/modprobe, network config etc..
> >>>7) run mkinitrd with --with=xenblk
> >>>8) exit chroot
> >>>9) umount, vgchange -an, kpartx -d the new file hierarchy
> >>>10) copy kernel & new initrd out of new file hierarchy onto somewhere
> >>>handy on Dom0.
> >>>11) build xm config file with kernel= and ramdisk= kernel and initrd
> >>>from step 10
> >>>
> >>>Obviously, this is not a detailed explanation, just an overview so
> >>>you see the general method I'm using.
> >>>
> >>>When I run 'xm create -c', it runs along nicely for a bit and then...
> >>>
> >>>...
> >>>Loading ext3.ko module
> >>>Loading xenblk.ko module
> >>>Registering block device major 8
> >>>blkfront: sda: barriers enabled
> >>> sda:end_request: I/O error, dev sda, sector 0
> >>>Buffer I/O error on device sda, logical block 0
> >>>BUG: unable to handle kernel paging request at virtual address
> >>>a031dcc8
> >>> printing eip:
> >>>ee02e928
> >>>01c96000 -> *pde = 00000000:38cda027
> >>>01c99000 -> *pme = 00000000:00000000
> >>>Oops: 0000 [#1]
> >>>SMP
> >>>last sysfs file: /block/ram0/dev
> >>>Modules linked in: xenblk ext3 jbd mbcache ehci_hcd ohci_hcd uhci_hcd
> >>>CPU:    0
> >>>EIP:    0061:[<ee02e928>]    Not tainted VLI
> >>>EFLAGS: 00010887   (2.6.20-2925.11.fc7xen #1)
> >>>EIP is at blkif_int+0x5a/0x18c [xenblk]
> >>>eax: e0009c00   ebx: c0314000   ecx: 000002c2   edx: 08000100
> >>>esi: 00000000   edi: c17160ac   ebp: c135cfc8   esp: c135cf9c
> >>>ds: 007b   es: 007b   ss: 0069
> >>>Process swapper (pid: 0, ti=c135c000 task=c12bd2e0 task.ti=c1307000)
> >>>Stack: 00000000 c135cfc8 c1036df8 00000001 00000002 00000001 08000100
> >>c12fa6b8
> >>>       c1d22980 00000000 00000000 c135cfe0 c1047682 00000105 c12fa680
> >>00000105
> >>>       c1d22980 c135cff8 c1048a74 c12fa6a8 c1307f18 00000105 c10489da
> >>c1307f34
> >>>Call Trace:
> >>> [<c1005d3a>] show_trace_log_lvl+0x1a/0x2f
> >>> [<c1005dea>] show_stack_log_lvl+0x9b/0xa3
> >>> [<c1005f86>] show_registers+0x194/0x26a
> >>> [<c100618d>] die+0x131/0x246
> >>> [<c11f79d5>] do_page_fault+0xaf7/0xc7b
> >>> [<c11f5cf5>] error_code+0x35/0x3c
> >>> [<c1047682>] handle_IRQ_event+0x1a/0x45
> >>> [<c1048a74>] handle_level_irq+0x9a/0xea
> >>> [<c1007018>] do_IRQ+0xba/0xe2
> >>> =======================
> >>>Code: e8 89 f6 8b 43 20 89 45 e0 e9 ed 00 00 00 8b 43 24 31 f6 48 23
> >>>45 e0 6b c0 6c 8d 78 40 03 7b 28 8b 17 69 c2 9c 00 00 00 89 55 ec <8b>
> >>>94 18 c8 00 00 00 8d 44 18 5c 89 45 f0 89 55 dc eb 11 8b 55
> >>>EIP: [<ee02e928>] blkif_int+0x5a/0x18c [xenblk] SS:ESP 0069:c135cf9c
> >>> <0>Kernel panic - not syncing: Fatal exception in interrupt
> >>>
> >>>Any ideas?
> >>>
> >>>-Dylan
> >>>
> >>>
> >>>
> >>>_______________________________________________
> >>>Xen-users mailing list
> >>>Xen-users@xxxxxxxxxxxxxxxxxxx
> >>>http://lists.xensource.com/xen-users
> >>
> >>_______________________________________________
> >>Xen-users mailing list
> >>Xen-users@xxxxxxxxxxxxxxxxxxx
> >>http://lists.xensource.com/xen-users
> >>
> >>__________ Informace od NOD32 2394 (20070711) __________
> >>
> >>Tato zprava byla proverena antivirovym systemem NOD32.
> >>http://www.nod32.cz
> >>
> >>
> >
> >_______________________________________________
> >Xen-users mailing list
> >Xen-users@xxxxxxxxxxxxxxxxxxx
> >http://lists.xensource.com/xen-users
> >
> 
> ----------------------------------------------------------------------
> tbrown@xxxxxxxxxxxxx   | "The Internet is a world of ends. You're at one
> http://BareMetal.com/  | end, and everybody and everything else are at the
> web hosting since '95  | other ends." - http://www.worldofends.com/

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users