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 - 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 - Non-affiliated event reporting
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, };
To make the Kernel config work between a driver and the iommufd core, move the _iommufd_object_alloc helper into a new driver.c file that builds with CONFIG_IOMMUFD_DRIVER.
Suggested-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com --- drivers/iommu/iommufd/Makefile | 2 +- drivers/iommu/iommufd/iommufd_private.h | 4 -- include/linux/iommu.h | 14 +++++++ include/linux/iommufd.h | 56 +++++++++++++++++++++++++ drivers/iommu/iommufd/driver.c | 38 +++++++++++++++++ drivers/iommu/iommufd/main.c | 32 -------------- 6 files changed, 109 insertions(+), 37 deletions(-) create mode 100644 drivers/iommu/iommufd/driver.c
diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile index cf4605962bea..435124a8e1f1 100644 --- a/drivers/iommu/iommufd/Makefile +++ b/drivers/iommu/iommufd/Makefile @@ -12,4 +12,4 @@ iommufd-y := \ iommufd-$(CONFIG_IOMMUFD_TEST) += selftest.o
obj-$(CONFIG_IOMMUFD) += iommufd.o -obj-$(CONFIG_IOMMUFD_DRIVER) += iova_bitmap.o +obj-$(CONFIG_IOMMUFD_DRIVER) += iova_bitmap.o driver.o diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 1bb8c0aaecd1..5bd41257f2ef 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -202,10 +202,6 @@ iommufd_object_put_and_try_destroy(struct iommufd_ctx *ictx, iommufd_object_remove(ictx, obj, obj->id, 0); }
-struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, - size_t size, - enum iommufd_object_type type); - #define __iommufd_object_alloc(ictx, ptr, type, obj) \ container_of(_iommufd_object_alloc( \ ictx, \ diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 4ad9b9ec6c9b..14f24b5cd16f 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 suggested 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 22948dd03d67..55054fbc793c 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 + * @free: Free all driver-specific parts of an iommufd_viommu. The memory of the + * vIOMMU will be free-ed by iommufd core after calling this free op. + */ +struct iommufd_viommu_ops { + void (*free)(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); @@ -135,4 +157,38 @@ static inline int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx) return -EOPNOTSUPP; } #endif /* CONFIG_IOMMUFD */ + +#if IS_ENABLED(CONFIG_IOMMUFD_DRIVER) +struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, + size_t size, + enum iommufd_object_type type); +#else /* !CONFIG_IOMMUFD_DRIVER */ +static inline struct iommufd_object * +_iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size, + enum iommufd_object_type type) +{ + return ERR_PTR(-EOPNOTSUPP); +} +#endif /* CONFIG_IOMMUFD_DRIVER */ + +/* + * 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) \ + ({ \ + struct drv_struct *ret; \ + \ + static_assert( \ + __same_type(struct iommufd_viommu, \ + ((struct drv_struct *)NULL)->member)); \ + static_assert(offsetof(struct drv_struct, member.obj) == 0); \ + ret = container_of( \ + _iommufd_object_alloc(ictx, sizeof(struct drv_struct), \ + IOMMUFD_OBJ_VIOMMU), \ + struct drv_struct, member.obj); \ + if (!IS_ERR(ret)) \ + ret->member.ops = viommu_ops; \ + ret; \ + }) #endif diff --git a/drivers/iommu/iommufd/driver.c b/drivers/iommu/iommufd/driver.c new file mode 100644 index 000000000000..c0876d3f91c7 --- /dev/null +++ b/drivers/iommu/iommufd/driver.c @@ -0,0 +1,38 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2024, NVIDIA CORPORATION & AFFILIATES + */ + +#include "iommufd_private.h" + +struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, + size_t size, + enum iommufd_object_type type) +{ + struct iommufd_object *obj; + int rc; + + obj = kzalloc(size, GFP_KERNEL_ACCOUNT); + if (!obj) + return ERR_PTR(-ENOMEM); + obj->type = type; + /* Starts out bias'd by 1 until it is removed from the xarray */ + refcount_set(&obj->shortterm_users, 1); + refcount_set(&obj->users, 1); + + /* + * Reserve an ID in the xarray but do not publish the pointer yet since + * the caller hasn't initialized it yet. Once the pointer is published + * in the xarray and visible to other threads we can't reliably destroy + * it anymore, so the caller must complete all errorable operations + * before calling iommufd_object_finalize(). + */ + rc = xa_alloc(&ictx->objects, &obj->id, XA_ZERO_ENTRY, xa_limit_31b, + GFP_KERNEL_ACCOUNT); + if (rc) + goto out_free; + return obj; +out_free: + kfree(obj); + return ERR_PTR(rc); +} +EXPORT_SYMBOL_NS_GPL(_iommufd_object_alloc, IOMMUFD); diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index b5f5d27ee963..92bd075108e5 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -29,38 +29,6 @@ struct iommufd_object_ops { static const struct iommufd_object_ops iommufd_object_ops[]; static struct miscdevice vfio_misc_dev;
-struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx, - size_t size, - enum iommufd_object_type type) -{ - struct iommufd_object *obj; - int rc; - - obj = kzalloc(size, GFP_KERNEL_ACCOUNT); - if (!obj) - return ERR_PTR(-ENOMEM); - obj->type = type; - /* Starts out bias'd by 1 until it is removed from the xarray */ - refcount_set(&obj->shortterm_users, 1); - refcount_set(&obj->users, 1); - - /* - * Reserve an ID in the xarray but do not publish the pointer yet since - * the caller hasn't initialized it yet. Once the pointer is published - * in the xarray and visible to other threads we can't reliably destroy - * it anymore, so the caller must complete all errorable operations - * before calling iommufd_object_finalize(). - */ - rc = xa_alloc(&ictx->objects, &obj->id, XA_ZERO_ENTRY, - xa_limit_31b, GFP_KERNEL_ACCOUNT); - if (rc) - goto out_free; - return obj; -out_free: - kfree(obj); - return ERR_PTR(rc); -} - /* * Allow concurrent access to the object. *