Re: [PATCH v7 6/6] Documentation: Update VFIO NOIOMMU mode

[Jacob Pan]

Hi Kevin,

On Wed, 3 Jun 2026 06:42:09 +0000
"Tian, Kevin" <kevin.tian@xxxxxxxxx> wrote:

> > From: Jacob Pan <jacob.pan@xxxxxxxxxxxxxxxxxxx>
> > Sent: Wednesday, June 3, 2026 1:45 PM
> > +
> > +* IOMMUFD UAPI is available for VFIO device cdev to pin and map
> > user memory with
> > +  the ability to retrieve physical addresses for DMA command
> > submission.  
> 
> and no need of mlock.
> 
> > +
> > +A new IOMMUFD ioctl IOMMU_IOAS_NOIOMMU_GET_PA is added to
> > retrieve the physical
> > +address for a given IOVA. Although there is no physical DMA
> > remapping hardware,
> > +IOMMU_IOAS_MAP_FIXED_IOVA is still used to establish IOVA-to-PA
> > mappings in the
> > +software page table for later IOMMU_IOAS_NOIOMMU_GET_PA lookups.
> > +tools/testing/selftests/vfio/vfio_iommufd_noiommu_test.c provides
> > an example of
> > +using this ioctl in no-IOMMU mode.
> > +  
> 
> the test case doesn't exist yet.
> 
will remove for now.

> Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>