Re: [PATCH RFC 02/11] iommu: Add iommu_domain type for SVA

[Lu Baolu]

On 2022/3/21 15:06, Tian, Kevin wrote:
> > From: Lu Baolu<baolu.lu@xxxxxxxxxxxxxxx>
> > Sent: Sunday, March 20, 2022 2:40 PM
> >
> > Add a new iommu domain type IOMMU_DOMAIN_SVA to represent an I/O
> > page
> > table which is shared from CPU host VA. Add a sva_cookie field in the
> > iommu_domain structure to save the mm_struct which represent the CPU
> > memory page table.
> >
> > Signed-off-by: Lu Baolu<baolu.lu@xxxxxxxxxxxxxxx>
> > ---
> >   include/linux/iommu.h | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> > index 36f43af0af53..3e179b853380 100644
> > --- a/include/linux/iommu.h
> > +++ b/include/linux/iommu.h
> > @@ -64,6 +64,9 @@ struct iommu_domain_geometry {
> >   #define __IOMMU_DOMAIN_PT	(1U << 2)  /* Domain is identity
> > mapped   */
> >   #define __IOMMU_DOMAIN_DMA_FQ	(1U << 3)  /* DMA-API uses
> > flush queue    */
> >
> > +#define __IOMMU_DOMAIN_SHARED	(1U << 4)  /* Page table shared from
> > CPU  */
> > +#define __IOMMU_DOMAIN_HOST_VA	(1U << 5)  /* Host CPU virtual
> > address */
> suppose the SHARED bit will be also used for KVM page table sharing and
> HOST_VA bit is to differentiate mm sharing from the latter?

Yes, that's my intention.

Best regards,
baolu