Re: [Qemu-devel] [PATCH fixup 2/2] vhost: genearlize iommu memory region

[Michael S. Tsirkin]

On Mon, Mar 20, 2017 at 05:07:34PM +0800, Peter Xu wrote:
> On Mon, Mar 20, 2017 at 11:36:39AM +0800, Jason Wang wrote:
> > We assumes the iommu_ops were attached to the root region of address
> > space. This may not true for all kinds of IOMMU implementation. So fix
> > this by not assume as->root has iommu_ops and:
> > 
> > - register a memory listener to dma_as
> > - during region_add, if it's a region of IOMMU, register a specific
> >   IOMMU notifier, and store all notifiers in a list
> > - during region_del, compare and delete the IOMMU notifier
> > 
> > This is a must for making vhost device IOTLB works for IOMMU other
> > than intel ones.
> > 
> > Signed-off-by: Jason Wang <address@hidden>
> 
> [...]
> 
> > @@ -1454,9 +1509,8 @@ int vhost_dev_start(struct vhost_dev *hdev, 
> > VirtIODevice *vdev)
> >          goto fail_features;
> >      }
> >  
> > -    if (vhost_dev_has_iommu(hdev)) {
> > -        memory_region_register_iommu_notifier(vdev->dma_as->root,
> > -                                              &hdev->n);
> > +    if (true) {
> 
> Here the if clause can be removed. And...
> 
> > +        memory_listener_register(&hdev->iommu_listener, vdev->dma_as);
> >      }
> >  
> >      r = hdev->vhost_ops->vhost_set_mem_table(hdev, hdev->mem);
> > @@ -1536,10 +1590,9 @@ void vhost_dev_stop(struct vhost_dev *hdev, 
> > VirtIODevice *vdev)
> >                               hdev->vq_index + i);
> >      }
> >  
> > -    if (vhost_dev_has_iommu(hdev)) {
> > +    if (true) {
> 
> ...here. Besides that:
> 
> Reviewed-by: Peter Xu <address@hidden>
> 
> Since this patchset depends on vtd vfio series and fixes its breakage
> to vhost, I'll pick them up for consistency for next post of vtd vfio
> series as well.
> 
> Thanks,
> 
> -- peterx

Sounds good. It's best to order patches in a way that avoids
breakages even for people that bisect though.
Might require some patch squashing.

-- 
MST