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

Zhu, Lingshan
2023-09-12T10:28:16Z

On 9/12/2023 6:16 PM, Parav Pandit wrote:
>> From: Zhu, Lingshan <lingshan.zhu@intel.com>
>> Sent: Tuesday, September 12, 2023 3:45 PM
>>
>> On 9/12/2023 5:35 PM, Parav Pandit wrote:
>>>> From: Zhu, Lingshan <lingshan.zhu@intel.com>
>>>> Sent: Tuesday, September 12, 2023 2:38 PM
>>>> supplementary: As Jason ever pointed out: the two solution can
>>>> co-exist for sure, I am implementing basic facilities, admin vq can
>>>> free feel to reuse them like forwarding messages to them, and this can help
>> support nested.
>>> Sure. Sounds good.
>>>
>>> At lest two device vendors + other industry bodies including led by Intel are
>> moving away from the register-based implementation in virtualization area.
>> This series is self-contained, it is an register based solution. It introduces basic
>> facilities, doesn't depend on others like AQ.
>>> And registers that you expose are not supporting device reset and FLR
>> sequence. So please add some text for that in PCI transport section about
>> violation.
>>> And guideline for driver on how it should not touch them to make this usable.
>>> This will make the nested solution more clear.
>> PCI FLR is out of this scope, for virtio you can still reset the device by writing 0.
>>> Do you find the administration commands we proposed in [1] useful for
>> nested case?
>>> If not, both will likely diverge.
>> Not till now.
>>> We would like to avoid suspending individual VQs in the passthrough case, as
>> things are controlled at the device level.
>>> It also reduces driver -> device interaction for large queue count ranging from
>> 1 to 32K.
>>> So at present I see very little overlap between the two. I will look more again
>> on 9/13 if passthrough proposal can utilize anything from your series.
>> It does not suspending an individual VQ, when suspend, all VQs are STOPPED.
> We need to stop configuration notifications as well and shared memory update etc.
already did if you have read my series