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

[Jason Wang]

On 2020/1/20 äå8:09, Michael S. Tsirkin wrote:
> On Mon, Jan 20, 2020 at 04:44:34PM +0800, Jason Wang wrote:
> > On 2020/1/19 äå5:59, 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

>