Re: [PATCH v9 7/8] qmp: add QMP command x-query-virtio-queue-element

[Markus Armbruster]

Jonah Palmer <jonah.palmer@oracle.com> writes:

> On 11/10/21 08:52, Markus Armbruster wrote:
>> Jonah Palmer<jonah.palmer@oracle.com>  writes:
>>
>>> From: Laurent Vivier<lvivier@redhat.com>
>>>
>>> This new command shows the information of a VirtQueue element.
>>>
>>> Signed-off-by: Jonah Palmer<jonah.palmer@oracle.com>
>> [...]
>>
>>> diff --git a/qapi/virtio.json b/qapi/virtio.json
>>> index 0f65044..c57fbc5 100644
>>> --- a/qapi/virtio.json
>>> +++ b/qapi/virtio.json
>>> @@ -1061,3 +1061,180 @@
>>>   { 'command': 'x-query-virtio-vhost-queue-status',
>>>     'data': { 'path': 'str', 'queue': 'uint16' },
>>>     'returns': 'VirtVhostQueueStatus', 'features': [ 'unstable' ] }
>>> +
>>> +##
>>> +# @VirtioRingDescFlags:
>>> +#
>>> +# An enumeration of the virtio ring descriptor flags
>>> +#
>>> +# Since: 6.3
>>> +#
>>> +##
>>> +
>>> +{ 'enum': 'VirtioRingDescFlags',
>>> +  'data': [ 'next', 'write', 'indirect', 'avail', 'used' ]
>>> +}
>>> +
>>> +##
>>> +# @VirtioRingDesc:
>>> +#
>>> +# Information regarding the VRing descriptor area
>>> +#
>>> +# @addr: guest physical address of the descriptor data
>>> +#
>>> +# @len: length of the descriptor data
>>> +#
>>> +# @flags: list of descriptor flags
>>> +#
>>> +# Since: 6.3
>>> +#
>>> +##
>>> +
>>> +{ 'struct': 'VirtioRingDesc',
>>> +  'data': { 'addr': 'uint64',
>>> +            'len': 'uint32',
>>> +            'flags': [ 'VirtioRingDescFlags' ] } }
>>> +
>>> +##
>>> +# @VirtioRingAvail:
>>> +#
>>> +# Information regarding the avail VRing (also known as the driver
>>> +# area)
>>> +#
>>> +# @flags: VRingAvail flags
>>> +#
>>> +# @idx: VRingAvail index
>>> +#
>>> +# @ring: VRingAvail ring[] entry at provided index
>>> +#
>>> +# Since: 6.3
>>> +#
>>> +##
>>> +
>>> +{ 'struct': 'VirtioRingAvail',
>>> +  'data': { 'flags': 'uint16',
>>> +            'idx': 'uint16',
>>> +            'ring': 'uint16' } }
>>> +
>>> +##
>>> +# @VirtioRingUsed:
>>> +#
>>> +# Information regarding the used VRing (also known as the device
>>> +# area)
>>> +#
>>> +# @flags: VRingUsed flags
>>> +#
>>> +# @idx: VRingUsed index
>>> +#
>>> +# Since: 6.3
>>> +#
>>> +##
>>> +
>>> +{ 'struct': 'VirtioRingUsed',
>>> +  'data': { 'flags': 'uint16',
>>> +            'idx': 'uint16' } }
>>> +
>>> +##
>>> +# @VirtioQueueElement:
>>> +#
>>> +# Information regarding a VirtQueue VirtQueueElement including
>>> +# descriptor, driver, and device areas
>>> +#
>>> +# @device-name: name of the VirtIODevice which this VirtQueue belongs
>>> +#               to (for reference)
>>> +#
>>> +# @index: index of the element in the queue
>>> +#
>>> +# @ndescs: number of descriptors
>>> +#
>>> +# @descs: list of the descriptors
>>
>> Can @ndescs ever be not equal to the length of @descs?
>>
>> If no, it's redundant.
>
> I don't believe so, no. Should I just remove @ndescs then?

Yes, please.

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