Re: [PATCH v2 2/8] iommu: Add attach/detach_dev_pasid domain ops

Lu Baolu
2022-03-18T11:52:43Z

On 2022/3/15 13:07, Jacob Pan wrote:
> From: Lu Baolu <baolu.lu@linux.intel.com>
>
> An IOMMU domain represents an address space which can be attached by
> devices that perform DMA within a domain. However, for platforms with
> PASID capability the domain attachment needs be handled at device+PASID
> level. There can be multiple PASIDs within a device and multiple devices
> attached to a given domain.
> This patch introduces a new IOMMU op which support device, PASID, and
> IOMMU domain attachment. The immediate use case is for PASID capable
> devices to perform DMA under DMA APIs.
>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
> include/linux/iommu.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 369f05c2a4e2..fde5b933dbe3 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -227,6 +227,8 @@ struct iommu_iotlb_gather {
> * @aux_get_pasid: get the pasid given an aux-domain
> * @sva_bind: Bind process address space to device
> * @sva_unbind: Unbind process address space from device
> + * @attach_dev_pasid: attach an iommu domain to a pasid of device
> + * @detach_dev_pasid: detach an iommu domain from a pasid of device
> * @sva_get_pasid: Get PASID associated to a SVA handle
> * @page_response: handle page request response
> * @cache_invalidate: invalidate translation caches
> @@ -296,6 +298,10 @@ struct iommu_ops {
> struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm,
> void *drvdata);
> void (*sva_unbind)(struct iommu_sva *handle);
> + int (*attach_dev_pasid)(struct iommu_domain *domain,
> + struct device *dev, ioasid_t id);
> + void (*detach_dev_pasid)(struct iommu_domain *domain,
> + struct device *dev, ioasid_t id);

As we have introduced iommu_domain_ops, these callbacks should be part
of the domain ops.

> u32 (*sva_get_pasid)(struct iommu_sva *handle);
>
> int (*page_response)(struct device *dev,

Best regards,
baolu