Re: [BUG] XEN domU crash when PV grub chainloads 32-bit domU grub

[Andreas Sundstrom <sunkan+lists.xen-devel@zappa.cx>]

Citerar Andrew Cooper <andrew.cooper3@citrix.com>:

> On 21/09/2015 21:03, Andreas Sundstrom wrote:
>> Using 64-bit dom0 and 32-bit domU PV (para-virtualized) grub sometimes
>> fail when chainloading the domU's grub. 64-bit domU seem to work 100%
>> of the time.
>
> You say sometimes.  Do you mean that repeated attempts to boot a 32bit
> domU causes it to ether boot correctly, or die in the below manor?

Yes that is correct, it may or may not be able to complete the booting.

>> When it fails "xl create vm -c" outputs this:
>> Parsing config from /etc/xen/vm
>> libxl: error: libxl_dom.c:35:libxl__domain_type: unable to get domain
>> type for domid=16
>> Unable to attach console
>> libxl: error: libxl_exec.c:118:libxl_report_child_exitstatus: console
>> child [0] exited with error status 1
>
> These error messages are just because the domain crashes sufficiently
> early that libxl can't find the console information.  Running `xl
> create` without '-c' would remove the libxl errors.

Correct, they only appear due to the failed connecting of the console
so not really relevant to the actual issue.

>> I am unable to understand how to debug grub further on my own, I have
>> printed out text from grub so that I understood that it is the
>> chainload that fails. I see no output from the domU grub (except when
>> it works as it should of course). I can help with further testing if
>> needed.
>
> It does appear to be an intermittent bug in 32bit grub-xen in the
> eventual domU, but I have no help to offer with respect to debugging
> grub-xen further.
>
> ~Andrew

As Ian Campbell suggested I have also filed a bug with upstream grub:
http://savannah.gnu.org/bugs/?46014

/Andreas