Re: [PATCH v3 01/10] iommu: Introduce Shared Virtual Addressing API

[Joerg Roedel <joro@8bytes.org>]

On Tue, Sep 25, 2018 at 03:46:42PM -0700, Jacob Pan wrote:
> On Tue, 25 Sep 2018 15:16:47 +0200
> Joerg Roedel <joro@8bytes.org> wrote:
> 
> > On Sun, Sep 23, 2018 at 10:39:25AM +0800, Lu Baolu wrote:
> > > > +int iommu_sva_init_device(struct device *dev, unsigned long
> > > > features,
> > > > +		       unsigned int min_pasid, unsigned int
> > > > max_pasid) +{
> > > > +	int ret;
> > > > +	struct iommu_sva_param *param;
> > > > +	struct iommu_domain *domain =
> > > > iommu_get_domain_for_dev(dev);  
> > > 
> > > This doesn't work for vt-d. The domains for host iova are
> > > self-managed by vt-d driver itself. Hence,
> > > iommu_get_domain_for_dev() will always return NULL unless an
> > > UNMANAGED domain is attached to the device.
> > > 
> > > How about
> > > 
> > >       const struct iommu_ops *ops = dev->bus->iommu_ops;
> > > 
> > > instead?  
> > 
> > The per-bus iommu-ops might go away sooner or later as we move to
> > per-device iommu-ops. How about fixing the VT-d driver to not keep
> > that domain internal to itself?
> > 
> Just to understand more specifically, you mean let VT-d driver also
> support IOMMU_DOMAIN_DMA as default domain?

Yes, bringing it on-par with other IOMMU drivers in this regard.

Regards,

	Joerg