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

[David Vrabel <david.vrabel@citrix.com>]

On 21/10/13 21:20, 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?

AMD Opteron 4264 with 8 GiB RAM.

Xen 4.4-unstable debug=y:

com1=115200,8n1 console=com1 crashkernel=256M@64M

Linux 3.12-rc4

root=/dev/mapper/cam--st09-root ro console=hvc0

Normal image:

build/sbin/kexec --debug --console-serial --serial-baud=115200
--command-line="console=ttyS0,115200n8 maxcpus=1" -l
/boot/vmlinuz-3.11.0.davidvr

Panic image:

build/sbin/kexec --debug --console-serial --serial-baud=115200
--command-line="console=ttyS0,115200n8 maxcpus=1" -p
/boot/vmlinuz-3.11.0.davidvr

David