Re: [Qemu-devel] [RFC PATCH 6/8] intel_iommu: support device iotlb descriptor

[Peter Xu <peterx@redhat.com>]

On Wed, Mar 30, 2016 at 01:08:45PM +0800, Jason Wang wrote:

[...]

> >> +    } else {
> >> +        sz = VTD_PAGE_SIZE;
> >> +    }
> >> +
> >> +    entry.target_as = &vtd_dev_as->as;
> >> +    entry.addr_mask = sz - 1;
> >> +    entry.iova = addr;
> >> +    memory_region_notify_iommu(entry.target_as->root, entry);
> > Here, we seems to be posting this invalidation to all registered
> > notifiers.
> 
> Yes, but only for a device specified address space.
> 
> >  Since this is a device-tlb invalidation, and we should
> > know which device (BDF) that we should invalidate, is there any way
> > that we can directly route this info to that specific device?
> 
> Looks like the codes has already done this, the target_as was found by
> bus num and devfn.

Yes, seems you are right. :)

-- peterx