Re: [Qemu-devel] [Question] dump memory when host pci device is used by guest

[Wen Congyang <wency@cn.fujitsu.com>]

At 10/24/2011 11:30 PM, Avi Kivity Write:
> On 10/24/2011 05:25 PM, Dave Anderson wrote:
>>
>> ----- Original Message -----
>>> On 10/24/2011 04:25 PM, Dave Anderson wrote:
>>>>> The question is that: 'virsh dump' can not be used when host pci device
>>>>> is used by guest. We are discussing how to fix the problem. We have determined
>>>>> that introduce a new monitor command dump. Jan suggested that the core file's
>>>>> format is gdb standard core format. Does crash support such format?  If no,
>>>>> is it possible to support such format?
>>>>
>>>> If you are talking about an ELF core dump of the user-space qemu-kvm process
>>>> running on the host, then it's certainly not supported.
>>>
>>> No, an ELF image of the guest's physical memory.
>>
>> Well then that should be pretty straight forward to support.  Depending upon
>> how similar it would be to the "standard" kdump ELF format, the only other
>> issue is how to determine the physical base address at which the kernel is
>> loaded, in order to be able to translate the mapped kernel-text/static-data
>> virtual region of the x86_64 arch (the __START_KERNEL_map region).
>>
> 
> I guess an elf note would work for that?

Hi, Avi Kivity, Dave Anderson

I have two questions about it:

1. How to know the guest's physical base address in qemu?

2. Does kdump format(not ELF) include such information in its head?

Thanks
Wen Congyang