[virtio-dev] Re: [virtio-comment] [PATCH 5/5] virtio-pci: implement VIRTIO_F_QUEUE_STATE

Zhu, Lingshan
2023-09-12T10:32:35Z

On 9/12/2023 6:25 PM, Parav Pandit wrote:
>> From: Zhu, Lingshan <lingshan.zhu@intel.com>
>> Sent: Tuesday, September 12, 2023 3:47 PM
>>
>> On 9/12/2023 5:28 PM, Parav Pandit wrote:
>>>> From: Zhu, Lingshan <lingshan.zhu@intel.com>
>>>> Sent: Tuesday, September 12, 2023 2:36 PM If you want AQ used for LM,
>>>> it should support nested anyway, don't break user logic.
>>> You ignored the other part of my question when you asked above.
>>> i.e. a PCI transport do not allow such weird bifurcation.
>> I failed to process your comment.
>> Do you mean the registers don't support nested?
> No. I mean registers access should support device reset flow and FLR flow.
DO you see this is a concern? Or why do you think there are problems?
>
>>>> This (my)series can support nested.
>>> Maybe it does, with hacking the device reset and FLR sequence, without dirty
>> tracking, without P2P support, without passthrough mode.
>>> All these requirements are not addressed.
>>>
>>> If you intent to cover both requirements, lets work towards it to see
>>> if it can converge, if there are technical challenges, then there is no point in
>> pushing to claim that in-band VF with mediation is the only way to move
>> forward.
>> Why do you need P2P?
> I answered this before few hours back.
still, why P2P is a blocker of my series?
>
>> Why FLR and reset are concerned?
> Because they must work.
why FLR and reset are affected? When SUSPEND, the device should stop
operation.
>> Why do you think dirty page tracking is not supported?
> Because you wrote in cover letter " Future work: dirty page tracking and in-flight descriptors."
> And you repeatedly resisted administration commands. I don’t see how above two can be done efficiently without administration commands.
> And if one is going to use administration command in future for above two, there is no point of doing current series over registers.
> I don’t see how and administration queue can work after device is suspended, and after FLR how dirty page tracking can continue.
>
> All these aspects are covered in [1] that can be extended for nesting if needed with side car VF.
>
> [1] https://lists.oasis-open.org/archives/virtio-comment/202309/msg00061.html
I will post V2 with in-flight descriptors tracking and dirty-page
tracking. They are not in this series bcasue
I want this series to focus and small