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iommufd: Introduce IOMMUFD_OBJ_VIOMMU and its related struct

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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,
    };

Link: https://patch.msgid.link/r/64685e2b79dea0f1dc56f6ede04809b72d578935.1730836219.git.nicolinc@nvidia.com
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>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
This commit is contained in:
Nicolin Chen 2024-11-05 12:04:19 -08:00 committed by Jason Gunthorpe
parent 7d4f46c237
commit 6b22d562fc
2 changed files with 54 additions and 0 deletions
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14
include/linux/iommu.h
View File

@ -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;

40
include/linux/iommufd.h
View File

@ -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);
@ -148,4 +170,22 @@ _iommufd_object_alloc(struct iommufd_ctx *ictx, size_t size,
return ERR_PTR(-EOPNOTSUPP);
}
#endif /* CONFIG_IOMMUFD_DRIVER_CORE */
/*
* 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