Re: [Qemu-devel] Re: [PATCH v2 12/15] monitor: Add basic device state visualization

[Markus Armbruster]

Avi Kivity <address@hidden> writes:

> On 05/23/2010 10:57 AM, Jan Kiszka wrote:
>> Avi Kivity wrote:
>>    
>>> On 05/22/2010 11:18 AM, Jan Kiszka wrote:
>>>      
>>>> From: Jan Kiszka<address@hidden>
>>>>
>>>> This introduces device_show, a monitor command that saves the vmstate of
>>>> a qdev device and visualizes it. QMP is also supported. Buffers are cut
>>>> after 16 byte by default, but the full content can be requested via
>>>> '-f'. To pretty-print sub-arrays, vmstate is extended to store the start
>>>> index name. A new qerror is introduced to signal a missing vmstate. And
>>>> it comes with documentation.
>>>>
>>>> +
>>>> +Dump a snapshot of the device state. Buffers are cut after 16 bytes
>>>> unless
>>>> +a full dump is requested.
>>>> +
>>>> +Arguments:
>>>> +
>>>> +- "path": the device's qtree path or unique ID (json-string)
>>>>
>>>>        
>>> This may be ambiguous.
>>>      
>> Can your elaborate what precisely is ambiguous?
>>    
>
> Can't the user choose the unique ID so that it aliases an unrelated
> qtree path?
>
> I prefer having mutually exclusive 'path' and 'ref' arguments.

Don't think that's necessary.  If the string starts with '/', it's an
absolute path.  Else, it's a relative path rooted at the node with the
ID equal to the first component.

Currently breaks down when IDs contain '/', but permitting that is a
bug.  There may be more problems; the path lookup code is way too
clever.