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

Matthew Rosato
2025-02-13T16:03:18Z

On 2/13/25 10:10 AM, Jason Gunthorpe wrote:
> 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
>

Thanks for reviewing again. And ACK, I will look at this for follow-on