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

[Wen Congyang]

At 10/18/2011 04:26 PM, Jan Kiszka Write:
> On 2011-10-18 10:25, Wen Congyang wrote:
>> At 10/18/2011 04:19 PM, Jan Kiszka Write:
>>> On 2011-10-18 09:58, Wen Congyang wrote:
>>>> At 10/18/2011 03:52 PM, Jan Kiszka Write:
>>>>> On 2011-10-18 09:15, Wen Congyang wrote:
>>>>>> Hi, Jan Kiszka
>>>>>>
>>>>>> At 10/10/2011 05:34 PM, Jan Kiszka Write:
>>>>>>> On 2011-10-10 11:02, Daniel P. Berrange wrote:
>>>>>>>> On Mon, Oct 10, 2011 at 08:52:08AM +0200, Jan Kiszka wrote:
>>>>>>
>>>>>>>
>>>>>>> Run gdb with "set debug remote 1" and watch the communication, it is not
>>>>>>> that complex. But a dump command is probably simpler for those
>>>>>>> scenarios, I agree.
>>>>>>
>>>>>> I have implemented the command dump and reuse migration's code. But I 
>>>>>> meet a problem
>>>>>> when I test it.
>>>>>
>>>>> Using migration code for dump is most probably the wrong approach as you
>>>>> saw through that conflict. All you need are the register states and the
>>>>> RAM. Reuse gdbstub services for this.
>>>>
>>>> Hmm, if the migration code can not be reused, I think we should define a 
>>>> new
>>>> qemu's vmcore format, and add some codes into crash to support such format.
>>>
>>> Please try to avoid defining something new. Unless there is a striking
>>> reason, standard gdb core files should be generated so that you can load
>>> the dump directly into gdb for analysis.
>>
>> I am not sure whehter the standard gdb core files can not be analyzed by 
>> crash.
>> If not, I think we should define something new because it's easier to use
>> crash than gdb to analyze the core files.
> 
> gdb allows you to walk up the frame and print variables (globals &
> local) etc.

Crash uses gdb to provide common function, and you can also use all the gdb 
commands
in crash.

Thanks
Wen Congyang

> 
> Jan
>