Re: [Qemu-devel] [RFC PATCH 12/20] Memory: Add func to fire pasidt_bind notifier

Liu, Yi L
2017-04-27T02:53:25Z

On Wed, Apr 26, 2017 at 03:50:16PM +0200, Paolo Bonzini wrote:
>
>
> On 26/04/2017 12:06, Liu, Yi L wrote:
> > +void memory_region_notify_iommu_svm_bind(MemoryRegion *mr,
> > + void *data)
> > +{
> > + IOMMUNotifier *iommu_notifier;
> > + IOMMUNotifierFlag request_flags;
> > +
> > + assert(memory_region_is_iommu(mr));
> > +
> > + /*TODO: support other bind requests with smaller gran,
> > + * e.g. bind signle pasid entry
> > + */
> > + request_flags = IOMMU_NOTIFIER_SVM_PASIDT_BIND;
> > +
> > + QLIST_FOREACH(iommu_notifier, &mr->iommu_notify, node) {
> > + if (iommu_notifier->notifier_flags & request_flags) {
> > + iommu_notifier->notify(iommu_notifier, data);
> > + break;
> > + }
> > + }
>
> Peter,
>
> should this reuse ->notify, or should it be different function pointer
> in IOMMUNotifier?

Hi Paolo,

Thx for your review.

I think it should be “->notify” here. In this patchset, the new notifier
is registered with the existing notifier registration API. So the all the
notifiers are in the mr->iommu_notify list. And notifiers are labeled
by notify flag, so it is able to differentiate the IOMMUNotifier nodes.
When the flag meets, trigger it by “->notify”. The diagram below shows
my understanding , wish it helps to make me understood.

VFIOContainer
|
giommu_list(VFIOGuestIOMMU)
\
VFIOGuestIOMMU1 -> VFIOGuestIOMMU2 -> VFIOGuestIOMMU3 ...
| | |
mr->iommu_notify: IOMMUNotifier -> IOMMUNotifier -> IOMMUNotifier
(Flag:MAP/UNMAP) (Flag:SVM bind) (Flag:tlb invalidate)

Actually, compared with the MAP/UNMAP notifier, the newly added notifier has
no start/end check, and there may be other types of bind notfier flag in
future, so I added a separate fire func for SVM bind notifier.

Thanks,
Yi L

> Paolo
>