From: Lu Baolu baolu.lu@linux.intel.com
Introduce a new domain type for a user I/O page table, which is nested on top of another user space address represented by a UNMANAGED domain. The mappings of a nested domain are managed by user space software, therefore it's unnecessary to have map/unmap callbacks. But the updates of the PTEs in the nested domain page table must be propagated to the caches on both IOMMU (IOTLB) and devices (DevTLB).
The nested domain is allocated by the domain_alloc_user op, and attached to the device through the existing iommu_attach_device/group() interfaces.
A new domain op, named cache_invalidate_user is added for the userspace to flush the hardware caches for a nested domain through iommufd. No wrapper for it, as it's only supposed to be used by iommufd.
Signed-off-by: Lu Baolu baolu.lu@linux.intel.com Co-developed-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com Signed-off-by: Yi Liu yi.l.liu@intel.com --- include/linux/iommu.h | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index ecbec2627b63..b8f09330b64e 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -66,6 +66,9 @@ struct iommu_domain_geometry {
#define __IOMMU_DOMAIN_SVA (1U << 4) /* Shared process address space */
+#define __IOMMU_DOMAIN_NESTED (1U << 5) /* User-managed address space nested + on a stage-2 translation */ + #define IOMMU_DOMAIN_ALLOC_FLAGS ~__IOMMU_DOMAIN_DMA_FQ /* * This are the possible domain-types @@ -92,6 +95,7 @@ struct iommu_domain_geometry { __IOMMU_DOMAIN_DMA_API | \ __IOMMU_DOMAIN_DMA_FQ) #define IOMMU_DOMAIN_SVA (__IOMMU_DOMAIN_SVA) +#define IOMMU_DOMAIN_NESTED (__IOMMU_DOMAIN_NESTED)
struct iommu_domain { unsigned type; @@ -350,6 +354,10 @@ struct iommu_ops { * @iotlb_sync_map: Sync mappings created recently using @map to the hardware * @iotlb_sync: Flush all queued ranges from the hardware TLBs and empty flush * queue + * @cache_invalidate_user: Flush hardware TLBs caching user space IO mappings + * @cache_invalidate_user_data_len: Defined length of input user data for the + * cache_invalidate_user op, being sizeof the + * structure in include/uapi/linux/iommufd.h * @iova_to_phys: translate iova to physical address * @enforce_cache_coherency: Prevent any kind of DMA from bypassing IOMMU_CACHE, * including no-snoop TLPs on PCIe or other platform @@ -379,6 +387,9 @@ struct iommu_domain_ops { size_t size); void (*iotlb_sync)(struct iommu_domain *domain, struct iommu_iotlb_gather *iotlb_gather); + int (*cache_invalidate_user)(struct iommu_domain *domain, + void *user_data); + const size_t cache_invalidate_user_data_len;
phys_addr_t (*iova_to_phys)(struct iommu_domain *domain, dma_addr_t iova);