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Subject: Re: [PATCH 3/5] vDPA: introduce vDPA bus
To:     "Michael S. Tsirkin" <mst@redhat.com>
Cc:     Shahaf Shuler <shahafs@mellanox.com>,
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From:   Jason Wang <jasowang@redhat.com>
Message-ID: <f5860f7e-f6c1-5bc7-53f5-c4badddfdfe4@redhat.com>
Date:   Tue, 21 Jan 2020 11:32:43 +0800
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On 2020/1/20 =E4=B8=8B=E5=8D=888:09, Michael S. Tsirkin wrote:
> On Mon, Jan 20, 2020 at 04:44:34PM +0800, Jason Wang wrote:
>> On 2020/1/19 =E4=B8=8B=E5=8D=885:59, 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 dri=
ver.
>>>> 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 ena=
bling
>> 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=20
mapping".

Thanks

>