Re: [PATCHv9 0/9] Xen: extend kexec hypercall for use with pv-ops kernels

[David Vrabel <dvrabel@cantab.net>]

On 25/10/13 10:13, Daniel Kiper wrote:
> On Mon, Oct 21, 2013 at 10:20:32PM +0200, Daniel Kiper wrote:
>> On Mon, Oct 21, 2013 at 01:56:09PM +0100, David Vrabel wrote:
>>> On 21/10/13 13:19, Daniel Kiper wrote:
>>>> On Sat, Oct 19, 2013 at 12:14:24AM +0100, David Vrabel wrote:
>>>>> On 18/10/2013 19:40, Daniel Kiper wrote:
>>>>>> On Tue, Oct 08, 2013 at 05:55:01PM +0100, David Vrabel wrote:
>>>>>>> The series (for Xen 4.4) improves the kexec hypercall by making Xen
>>>>>>> responsible for loading and relocating the image.  This allows kexec
>>>>>>> to be usable by pv-ops kernels and should allow kexec to be usable
>>>>>>> from a HVM or PVH privileged domain.
>>>>>>
>>>>>> I could not load panic image because Xen crashes in following way:
>>>>>>
>>>>>> (XEN) ----[ Xen-4.4-unstable  x86_64  debug=y  Tainted:    C ]----
>>>>> [...]
>>>>>> (XEN) Xen call trace:
>>>>>> (XEN)    [<ffff82d080114ef2>] kimage_free+0x67/0xd2
>>>>>> (XEN)    [<ffff82d0801151f9>] do_kimage_alloc+0x29c/0x2f0
>>>>>> (XEN)    [<ffff82d0801152fe>] kimage_alloc+0xb1/0xe6
>>>>>> (XEN)    [<ffff82d0801144c0>] do_kexec_op_internal+0x68e/0x789
>>>>>> (XEN)    [<ffff82d0801145c9>] do_kexec_op+0xe/0x12
>>>>>> (XEN)    [<ffff82d0802268cb>] syscall_enter+0xeb/0x145
>>>>>
>>>>> The appended patch should fix this crash which only occurs if there's an
>>>>> error in do_kimage_alloc().
>>>>
>>>> Patch had wrapped lines. I hope that I fixed it properly.
>>>> I cannot load panic kernel. kexec fails with following message:
>>>>
>>>> kexec_load failed: Cannot assign requested address
>>>
>>> This is -EADDRINVALID which means one of
>>>
>>> a) the entry point isn't within a segment.
>>> b) one of the segments is not page aligned.
>>> c) one of the segments is not within the crash region.
>>>
>>> But the segments kexec has constructed all looked fine to me (and
>>> similar to the segments I see).
>>>
>>> I'm afraid I cannot reproduce either of your failures.  Are you sure
>>> you've built everything correctly?  In particular has kexec-tools been
>>> built against the correct version of Xen headers?
>>
>> It looks that I build it correctly but I will double check it.
>> Could you send me your Xen/Linux boot command lines and kexec
>> command lines for normal and panic kernel? Could you tell me
>> what is your RAM size?
>
> Ping? This info will help me to dig deeper in this issue.

Sorry, I've been at the Xen Developers Summit and haven't had easy 
access to my test box to gather this information.  I'll get this when 
I'm back in the office on Monday.

David