Re: [PATCH v9 04/11] iommu: Add sva iommu_domain support

[Baolu Lu]

On 2022/6/28 16:50, Tian, Kevin wrote:
> > From: Baolu Lu<baolu.lu@xxxxxxxxxxxxxxx>
> > Sent: Tuesday, June 28, 2022 1:41 PM
> > > >    struct iommu_domain {
> > > >    	unsigned type;
> > > >    	const struct iommu_domain_ops *ops;
> > > >    	unsigned long pgsize_bitmap;	/* Bitmap of page sizes in use */
> > > > -	iommu_fault_handler_t handler;
> > > > -	void *handler_token;
> > > >    	struct iommu_domain_geometry geometry;
> > > >    	struct iommu_dma_cookie *iova_cookie;
> > > > +	union {
> > > > +		struct {	/* IOMMU_DOMAIN_DMA */
> > > > +			iommu_fault_handler_t handler;
> > > > +			void *handler_token;
> > > > +		};
> > > why is it DMA domain specific? What about unmanaged
> > > domain? Unrecoverable fault can happen on any type
> > > including SVA. Hence I think above should be domain type
> > > agnostic.
> > The report_iommu_fault() should be replaced by the new
> > iommu_report_device_fault(). Jean has already started this work.
> >
> > https://lore.kernel.org/linux-iommu/Yo4Nw9QyllT1RZbd@myrica/
> >
> > Currently this is only for DMA domains, hence Robin suggested to make it
> > exclude with the SVA domain things.
> >
> > https://lore.kernel.org/linux-iommu/f3170016-4d7f-e78e-db48-
> > 68305f683349@xxxxxxx/
> Then it's worthy a comment that those two fields are for
> some legacy fault reporting stuff and DMA type only.

The iommu_fault and SVA fields are exclusive. The former is used for
unrecoverable DMA remapping faults, while the latter is only interested
in the recoverable page faults.

I will update the commit message with above explanation. Does this work
for you?

Best regards,
baolu