[Libguestfs] Double fault panic in L2 upon v2v conversion

[Richard W.M. Jones]

[Please keep libguestfs mailing list in CC]

On Fri, Jan 17, 2014 at 04:14:03PM +0200, Rom Freiman wrote:
> How do you know that the problem is with KVM/QEMU and not with libguestfs?

The guestfsd daemon is simply running the regular 'mount' command.
The mount command causes the kernel to panic.  There should be no
circumstances where running an ordinary command like that, albeit as
root, should cause the kernel to panic.  Unless the kernel (or in this
case, something underneath the kernel) is broken.

mount -o ro /dev/sdb /sysroot/
[   12.645305] PANIC: double fault, error_code: 0x0
[   12.645305] CPU: 0 PID: 141 Comm: mount Not tainted 
3.11.8-200.strato0002.fc19.strato.c3850ae03e9d.x86_64 #1  
[   12.645305] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.645305] task: ffff88001cc816e0 ti: ffff88001cde6000 task.ti:
ffff88001cde6000
[   12.645305] RIP: 0033:[<00007fa602c5b99b>]  [<00007fa602c5b99b>]
0x7fa602c5b99a  
[   12.645305] RSP: 002b:00007fff4f5884a0  EFLAGS: 00010216
[   12.645305] RAX: 00007fa602008ff8 RBX: 00007fa601ff0000 RCX: 00007fa601ff0000
[   12.645305] RDX: 00000000003b7068 RSI: 00007fff4f588560 RDI: 00007fa601ff3d18
[   12.645305] RBP: 00007fff4f5885d0 R08: 00007fa60200f310 R09: 0000000000000000
[   12.645305] R10: 0000000000000022 R11: 00007fa60200f310 R12: 00007fa60200e9b0
[   12.645305] R13: 0000000000000000 R14: 0000000000000000 R15: 00007fa602e6e990
[   12.645305] FS:  00007fa602e69880(0000) GS:ffff88001f000000(0000)
knlGS:0000000000000000
[   12.645305] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[   12.645305] CR2: 0000000000000000 CR3: 000000001d7fb000 CR4: 00000000000006f0
[   12.645305]
[   12.645305] Kernel panic - not syncing: Machine halted.
[   12.645305] CPU: 0 PID: 141 Comm: mount Not tainted
3.11.8-200.strato0002.fc19.strato.c3850ae03e9d.x86_64 #1
[   12.645305] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.645305]  ffff88001f005f58 ffff88001f005e90 ffffffff8164024b
ffffffff819e89dc
[   12.645305]  ffff88001f005f08 ffffffff8163c272 0000000000000008
ffff88001f005f18
[   12.645305]  ffff88001f005eb8 ffffffff8163c8e5 0000000000000046
00000000000000b1
[   12.645305] Call Trace:
[   12.645305]  <#DF>  [<ffffffff8164024b>] dump_stack+0x45/0x56
[   12.645305]  [<ffffffff8163c272>] panic+0xc8/0x1d7
[   12.645305]  [<ffffffff8163c8e5>] ? printk+0x67/0x69
[   12.645305]  [<ffffffff81048ae1>] df_debug+0x31/0x40
[   12.645305]  [<ffffffff810132ed>] do_double_fault+0x5d/0x80
[   12.645305]  [<ffffffff81650b88>] double_fault+0x28/0x30
[   12.645305]  <<EOE>>

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into KVM guests.
http://libguestfs.org/virt-v2v