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:

quoted

On 2020/1/19 下午5:59, Michael S. Tsirkin wrote:

quoted

On Sun, Jan 19, 2020 at 09:07:09AM +0000, Shahaf Shuler wrote:

quoted

quoted

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