Re: [PATCH v5 4/4] iommu/s390: implement iommu passthrough via identity domain

Jason Gunthorpe
2025-02-13T15:10:42Z

On Wed, Feb 12, 2025 at 04:34:18PM -0500, Matthew Rosato wrote:
> Enabled via the kernel command-line 'iommu.passthrough=1' option.
>
> Introduce the concept of identity domains to s390-iommu, which relies on
> the bus_dma_region to offset identity mappings to the start of the DMA
> aperture advertized by CLP.
>
> Tested-by: Niklas Schnelle <schnelle@linux.ibm.com>
> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
> ---
> drivers/iommu/s390-iommu.c | 95 +++++++++++++++++++++++++++++---------
> 1 file changed, 72 insertions(+), 23 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

This may want to be changed to use

https://lore.kernel.org/linux-iommu/2-v1-91eed9c8014a+53a37-iommu_virtio_domains_jgg@nvidia.com/

Later on

Jason