Add a new IOMMUFD_OBJ_VIOMMU with an iommufd_viommu structure to represent a slice of physical IOMMU device passed to or shared with a user space VM. This slice, now a vIOMMU object, is a group of virtualization resources of a physical IOMMU's, such as: - Security namespace for guest owned ID, e.g. guest-controlled cache tags - Non-device-affiliated event reporting, e.g. invalidation queue errors - Access to a sharable nesting parent pagetable across physical IOMMUs - Virtualization of various platforms IDs, e.g. RIDs and others - Delivery of paravirtualized invalidation - Direct assigned invalidation queues - Direct assigned interrupts
Add a new viommu_alloc op in iommu_ops, for drivers to allocate their own vIOMMU structures. And this allocation also needs a free(), so add struct iommufd_viommu_ops.
To simplify a vIOMMU allocation, provide a iommufd_viommu_alloc() helper. It's suggested that a driver should embed a core-level viommu structure in its driver-level viommu struct and call the iommufd_viommu_alloc() helper, meanwhile the driver can also implement a viommu ops: struct my_driver_viommu { struct iommufd_viommu core; /* driver-owned properties/features */ .... };
static const struct iommufd_viommu_ops my_driver_viommu_ops = { .free = my_driver_viommu_free, /* future ops for virtualization features */ .... };
static struct iommufd_viommu my_driver_viommu_alloc(...) { struct my_driver_viommu *my_viommu = iommufd_viommu_alloc(ictx, my_driver_viommu, core, my_driver_viommu_ops); /* Init my_viommu and related HW feature */ .... return &my_viommu->core; }
static struct iommu_domain_ops my_driver_domain_ops = { .... .viommu_alloc = my_driver_viommu_alloc, };
Suggested-by: Jason Gunthorpe jgg@nvidia.com Reviewed-by: Kevin Tian kevin.tian@intel.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com --- include/linux/iommu.h | 14 ++++++++++++++ include/linux/iommufd.h | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 54 insertions(+)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index bd722f473635..2574fc8abaf2 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -42,6 +42,8 @@ struct notifier_block; struct iommu_sva; struct iommu_dma_cookie; struct iommu_fault_param; +struct iommufd_ctx; +struct iommufd_viommu;
#define IOMMU_FAULT_PERM_READ (1 << 0) /* read */ #define IOMMU_FAULT_PERM_WRITE (1 << 1) /* write */ @@ -542,6 +544,14 @@ static inline int __iommu_copy_struct_from_user_array( * @remove_dev_pasid: Remove any translation configurations of a specific * pasid, so that any DMA transactions with this pasid * will be blocked by the hardware. + * @viommu_alloc: Allocate an iommufd_viommu on a physical IOMMU instance behind + * the @dev, as the set of virtualization resources shared/passed + * to user space IOMMU instance. And associate it with a nesting + * @parent_domain. The @viommu_type must be defined in the header + * include/uapi/linux/iommufd.h + * It is required to call iommufd_viommu_alloc() helper for + * a bundled allocation of the core and the driver structures, + * using the given @ictx pointer. * @pgsize_bitmap: bitmap of all possible supported page sizes * @owner: Driver module providing these ops * @identity_domain: An always available, always attachable identity @@ -591,6 +601,10 @@ struct iommu_ops { void (*remove_dev_pasid)(struct device *dev, ioasid_t pasid, struct iommu_domain *domain);
+ struct iommufd_viommu *(*viommu_alloc)( + struct device *dev, struct iommu_domain *parent_domain, + struct iommufd_ctx *ictx, unsigned int viommu_type); + const struct iommu_domain_ops *default_domain_ops; unsigned long pgsize_bitmap; struct module *owner; diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index 2f72452fad27..457e763e8b63 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -17,6 +17,7 @@ struct iommu_group; struct iommufd_access; struct iommufd_ctx; struct iommufd_device; +struct iommufd_viommu_ops; struct page;
enum iommufd_object_type { @@ -28,6 +29,7 @@ enum iommufd_object_type { IOMMUFD_OBJ_IOAS, IOMMUFD_OBJ_ACCESS, IOMMUFD_OBJ_FAULT, + IOMMUFD_OBJ_VIOMMU, #ifdef CONFIG_IOMMUFD_TEST IOMMUFD_OBJ_SELFTEST, #endif @@ -78,6 +80,26 @@ void iommufd_access_detach(struct iommufd_access *access);
void iommufd_ctx_get(struct iommufd_ctx *ictx);
+struct iommufd_viommu { + struct iommufd_object obj; + struct iommufd_ctx *ictx; + struct iommu_device *iommu_dev; + struct iommufd_hwpt_paging *hwpt; + + const struct iommufd_viommu_ops *ops; + + unsigned int type; +}; + +/** + * struct iommufd_viommu_ops - vIOMMU specific operations + * @destroy: Clean up all driver-specific parts of an iommufd_viommu. The memory + * of the vIOMMU will be free-ed by iommufd core after calling this op + */ +struct iommufd_viommu_ops { + void (*destroy)(struct iommufd_viommu *viommu); +}; + #if IS_ENABLED(CONFIG_IOMMUFD) struct iommufd_ctx *iommufd_ctx_from_file(struct file *file); struct iommufd_ctx *iommufd_ctx_from_fd(int fd); @@ -145,4 +167,22 @@ _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size, return ERR_PTR(-EOPNOTSUPP); } #endif /* CONFIG_IOMMUFD */ + +/* + * Helpers for IOMMU driver to allocate driver structures that will be freed by + * the iommufd core. The free op will be called prior to freeing the memory. + */ +#define iommufd_viommu_alloc(ictx, drv_struct, member, viommu_ops) \ + ({ \ + drv_struct *ret; \ + \ + static_assert(__same_type(struct iommufd_viommu, \ + ((drv_struct *)NULL)->member)); \ + static_assert(offsetof(drv_struct, member.obj) == 0); \ + ret = (drv_struct *)_iommufd_object_alloc( \ + ictx, sizeof(drv_struct), IOMMUFD_OBJ_VIOMMU); \ + if (!IS_ERR(ret)) \ + ret->member.ops = viommu_ops; \ + ret; \ + }) #endif