Re: [PATCH v2 4/6] migration: Fix analyze-migration.py when ignore-shared is used

[Juan Quintela <quintela@redhat.com>]

Fabiano Rosas <farosas@suse.de> wrote:
> Juan Quintela <quintela@redhat.com> writes:
>
>> Fabiano Rosas <farosas@suse.de> wrote:
>>> The script is currently broken when the x-ignore-shared capability is
>>> used:
>>>
>>> Traceback (most recent call last):
>>>   File "./scripts/analyze-migration.py", line 656, in <module>
>>>     dump.read(dump_memory = args.memory)
>>>   File "./scripts/analyze-migration.py", line 593, in read
>>>     section.read()
>>>   File "./scripts/analyze-migration.py", line 163, in read
>>>     self.name = self.file.readstr(len = namelen)
>>>   File "./scripts/analyze-migration.py", line 53, in readstr
>>>     return self.readvar(len).decode('utf-8')
>>> UnicodeDecodeError: 'utf-8' codec can't decode byte 0x82 in position 55: invalid start byte
>>>
>>> We're currently adding data to the middle of the ram section depending
>>> on the presence of the capability. As a consequence, any code loading
>>> the ram section needs to know about capabilities so it can interpret
>>> the stream.
>>>
>>> Skip the byte that's added when x-ignore-shared is used to fix the
>>> script.
>>>
>>> Signed-off-by: Fabiano Rosas <farosas@suse.de>
>>
>> Reviewed-by: Juan Quintela <quintela@redhat.com>
>>
>>> @@ -582,6 +586,7 @@ def read(self, desc_only = False, dump_memory = False, write_memory = False):
>>>                  config_desc = self.vmsd_desc.get('configuration')
>>>                  section = ConfigurationSection(file, config_desc)
>>>                  section.read()
>>> +                ramargs['ignore_shared'] = section.has_capability('x-ignore-shared')
>>
>> should we consider s/x-ignore-shared/ignore-shared/?
>>
>
> We can consider s/ignore-shared/x-ignore-shared/ if that's what you
> mean. The way you suggested doesn't work because the cap name comes from
> QEMU with the "x-" part in it.
>
> If you meant filtering the x out when parsing the capabilities in this
> script, I think that would cause a sort of a UX issue because we need to
> use x-ignore-shared to set the cap in QMP/HMP.

No.

I mean if we should start supporting ignore-shared.

Later, Juan.