Re: [PATCH RFC 09/10] migration/dirtyrate: Expand dirty_bitmap to be tracked separately for devices

[Joao Martins]

On 5/2/22 13:54, Markus Armbruster wrote:
> Joao Martins <joao.m.martins@oracle.com> writes:
> 
>> Expand dirtyrate measurer that is accessible via HMP calc_dirty_rate
>> or QMP 'calc-dirty-rate' to receive a @scope argument. The scope
>> then restricts the dirty tracking to be done at devices only,
>> while neither enabling or using the KVM (CPU) dirty tracker.
>> The default stays as is i.e. dirty-ring / dirty-bitmap from KVM.
>>
>> This is useful to test, exercise the IOMMU dirty tracker and observe
>> how much a given device is dirtying memory.
>>
>> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
> 
> [...]
> 
>> diff --git a/qapi/migration.json b/qapi/migration.json
>> index 27d7b281581d..082830c6e771 100644
>> --- a/qapi/migration.json
>> +++ b/qapi/migration.json
>> @@ -1793,6 +1793,19 @@
>>  { 'enum': 'DirtyRateMeasureMode',
>>    'data': ['page-sampling', 'dirty-ring', 'dirty-bitmap'] }
>>  
>> +##
>> +# @DirtyRateScope:
>> +#
>> +# An enumeration of scope of measuring dirtyrate.
> 
> "dirtyrate" is not a word.
> 
Indeed. I will be more verbose rather than using 'dirty rate'.

>> +#
>> +# @dirty-devices: calculate dirtyrate by devices only.
> 
> Please document @all, too.
> 
OK. I probably should have used 'vcpu' and 'devices',
rather than 'all' and 'dirty-devices'

>> +#
>> +# Since: 6.2
>> +#

This should be 7.1.

>> +##
>> +{ 'enum': 'DirtyRateScope',
>> +  'data': ['all', 'dirty-devices'] }
>> +
>>  ##
>>  # @DirtyRateInfo:
>>  #
>> @@ -1827,6 +1840,7 @@
>>             'calc-time': 'int64',
>>             'sample-pages': 'uint64',
>>             'mode': 'DirtyRateMeasureMode',
>> +           'scope': 'DirtyRateScope',
> 
> Please document new member @scope.
> 
OK.