Re: [PATCH 3/5] vDPA: introduce vDPA bus

Jason Wang
2020-01-21T03:33:11Z

On 2020/1/20 下午8:09, Michael S. Tsirkin wrote:
> On Mon, Jan 20, 2020 at 04:44:34PM +0800, Jason Wang wrote:
>> On 2020/1/19 下午5:59, Michael S. Tsirkin wrote:
>>> On Sun, Jan 19, 2020 at 09:07:09AM +0000, Shahaf Shuler wrote:
>>>>> Technically, we can keep the incremental API
>>>>> here and let the vendor vDPA drivers to record the full mapping
>>>>> internally which may slightly increase the complexity of vendor driver.
>>>> What will be the trigger for the driver to know it received the last mapping on this series and it can now push it to the on-chip IOMMU?
>>> Some kind of invalidate API?
>>>
>> The problem is how to deal with the case of vIOMMU. When vIOMMU is enabling
>> there's no concept of last mapping.
>>
>> Thanks
> Most IOMMUs have a translation cache so have an invalidate API too.

Ok, then I get you.

But in this case, when vIOMMU is enabled, each new map became a "last
mapping".

Thanks

>