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

[Jan Kiszka]

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.

Jan

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