Re: [RFC 7/7] vfio: Add vfio_register_pasid_iommu_dev()

Yi Liu
2023-11-17T06:28:16Z

On 2023/11/16 13:12, Cao, Yahui wrote:
>
> On 10/9/2023 4:51 PM, Yi Liu wrote:
>> From: Kevin Tian<kevin.tian@intel.com>
>>
>> This adds vfio_register_pasid_iommu_dev() for device driver to register
>> virtual devices which are isolated per PASID in physical IOMMU. The major
>> usage is for the SIOV devices which allows device driver to tag the DMAs
>> out of virtual devices within it with different PASIDs.
>>
>> For a given vfio device, VFIO core creates both group user interface and
>> device user interface (device cdev) if configured. However, for the virtual
>> devices backed by PASID of the device, VFIO core shall only create device
>> user interface as there is no plan to support such devices in the legacy
>> vfio_iommu drivers which is a must if creating group user interface for
>> such virtual devices. This introduces a VFIO_PASID_IOMMU group type for
>> the device driver to register PASID virtual devices, and provides a wrapper
>> API for it. In particular no iommu group (neither fake group or real group)
>> exists per PASID, hence no group interface for this type.
>>
>> Signed-off-by: Kevin Tian<kevin.tian@intel.com>
>> Signed-off-by: Yi Liu<yi.l.liu@intel.com>
>> ---
>>   drivers/vfio/group.c     | 18 ++++++++++++++++++
>>   drivers/vfio/vfio.h      |  8 ++++++++
>>   drivers/vfio/vfio_main.c | 10 ++++++++++
>>   include/linux/vfio.h     |  1 +
>>   4 files changed, 37 insertions(+)
>>
>> ...
>> ...
>> +/*
>> + * Register a virtual device with IOMMU pasid protection. The user of
>> + * this device can trigger DMA as long as all of its outgoing DMAs are
>> + * always tagged with a pasid.
>> + */
>> +int vfio_register_pasid_iommu_dev(struct vfio_device *device)
>> +{
>> +    return __vfio_register_dev(device, VFIO_PASID_IOMMU);
>> +}
>> +
>
>
> Missing symbol export here.
>
fixed.

--
Regards,
Yi Liu