In nested translation, the stage-1 page table is user-managed but cached by the IOMMU hardware, so an update on present page table entries in the stage-1 page table should be followed with a cache invalidation.
Add an IOMMU_HWPT_INVALIDATE ioctl to support such a cache invalidation. It takes hwpt_id to specify the iommu_domain, and a multi-entry array to support multiple invalidation requests in one ioctl.
Check cache_invalidate_user op in the iommufd_hw_pagetable_alloc_nested, since all nested domains need that.
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 --- drivers/iommu/iommufd/hw_pagetable.c | 35 ++++++++++++++++++++++++ drivers/iommu/iommufd/iommufd_private.h | 9 +++++++ drivers/iommu/iommufd/main.c | 3 +++ include/uapi/linux/iommufd.h | 36 +++++++++++++++++++++++++ 4 files changed, 83 insertions(+)
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c index 362c694aac9b..6090d59c4982 100644 --- a/drivers/iommu/iommufd/hw_pagetable.c +++ b/drivers/iommu/iommufd/hw_pagetable.c @@ -238,6 +238,11 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx, rc = -EINVAL; goto out_abort; } + /* Driver is buggy by missing cache_invalidate_user in domain_ops */ + if (WARN_ON_ONCE(!hwpt->domain->ops->cache_invalidate_user)) { + rc = -EINVAL; + goto out_abort; + } return hwpt_nested;
out_abort: @@ -323,3 +328,33 @@ int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd) iommufd_put_object(&idev->obj); return rc; } + +int iommufd_hwpt_invalidate(struct iommufd_ucmd *ucmd) +{ + struct iommu_hwpt_invalidate *cmd = ucmd->cmd; + struct iommu_user_data_array data_array = { + .type = cmd->req_type, + .uptr = u64_to_user_ptr(cmd->reqs_uptr), + .entry_len = cmd->req_len, + .entry_num = cmd->req_num, + }; + struct iommufd_hw_pagetable *hwpt; + int rc = 0; + + if (cmd->req_type == IOMMU_HWPT_DATA_NONE) + return -EINVAL; + if (!cmd->reqs_uptr || !cmd->req_len || !cmd->req_num) + return -EINVAL; + + hwpt = iommufd_hw_pagetable_get_nested(ucmd, cmd->hwpt_id); + if (IS_ERR(hwpt)) + return PTR_ERR(hwpt); + + rc = hwpt->domain->ops->cache_invalidate_user(hwpt->domain, &data_array, + &cmd->out_driver_error_code); + cmd->req_num = data_array.entry_num; + if (iommufd_ucmd_respond(ucmd, sizeof(*cmd))) + return -EFAULT; + iommufd_put_object(&hwpt->obj); + return rc; +} diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index a829458fe762..7ec629599844 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -279,6 +279,7 @@ void iommufd_hwpt_paging_abort(struct iommufd_object *obj); void iommufd_hwpt_nested_destroy(struct iommufd_object *obj); void iommufd_hwpt_nested_abort(struct iommufd_object *obj); int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd); +int iommufd_hwpt_invalidate(struct iommufd_ucmd *ucmd);
static inline void iommufd_hw_pagetable_put(struct iommufd_ctx *ictx, struct iommufd_hw_pagetable *hwpt) @@ -300,6 +301,14 @@ static inline void iommufd_hw_pagetable_put(struct iommufd_ctx *ictx, refcount_dec(&hwpt->obj.users); }
+static inline struct iommufd_hw_pagetable * +iommufd_hw_pagetable_get_nested(struct iommufd_ucmd *ucmd, u32 id) +{ + return container_of(iommufd_get_object(ucmd->ictx, id, + IOMMUFD_OBJ_HWPT_NESTED), + struct iommufd_hw_pagetable, obj); +} + struct iommufd_group { struct kref ref; struct mutex lock; diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index f94c14f20918..1f2d2d262e12 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -307,6 +307,7 @@ union ucmd_buffer { struct iommu_destroy destroy; struct iommu_hw_info info; struct iommu_hwpt_alloc hwpt; + struct iommu_hwpt_invalidate cache; struct iommu_ioas_alloc alloc; struct iommu_ioas_allow_iovas allow_iovas; struct iommu_ioas_copy ioas_copy; @@ -342,6 +343,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { __reserved), IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc, __reserved), + IOCTL_OP(IOMMU_HWPT_INVALIDATE, iommufd_hwpt_invalidate, + struct iommu_hwpt_invalidate, out_driver_error_code), IOCTL_OP(IOMMU_IOAS_ALLOC, iommufd_ioas_alloc_ioctl, struct iommu_ioas_alloc, out_ioas_id), IOCTL_OP(IOMMU_IOAS_ALLOW_IOVAS, iommufd_ioas_allow_iovas, diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index d82bc663c5cd..fc305a48ab81 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -47,6 +47,7 @@ enum { IOMMUFD_CMD_VFIO_IOAS, IOMMUFD_CMD_HWPT_ALLOC, IOMMUFD_CMD_GET_HW_INFO, + IOMMUFD_CMD_HWPT_INVALIDATE, };
/** @@ -477,4 +478,39 @@ struct iommu_hw_info { __u32 __reserved; }; #define IOMMU_GET_HW_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_GET_HW_INFO) + +/** + * struct iommu_hwpt_invalidate - ioctl(IOMMU_HWPT_INVALIDATE) + * @size: sizeof(struct iommu_hwpt_invalidate) + * @hwpt_id: HWPT ID of a nested HWPT for cache invalidation + * @reqs_uptr: User pointer to an array having @req_num of cache invalidation + * requests. The request entries in the array are of fixed width + * @req_len, and contain a user data structure for invalidation + * request specific to the given hardware page table. + * @req_type: One of enum iommu_hwpt_data_type, defining the data type of all + * the entries in the invalidation request array. It should suit + * with the data_type passed per the allocation of the hwpt pointed + * by @hwpt_id. + * @req_len: Length (in bytes) of a request entry in the request array + * @req_num: Input the number of cache invalidation requests in the array. + * Output the number of requests successfully handled by kernel. + * @out_driver_error_code: Report a driver speicifc error code upon failure. + * It's optional, driver has a choice to fill it or + * not. + * + * Invalidate the iommu cache for user-managed page table. Modifications on a + * user-managed page table should be followed by this operation to sync cache. + * Each ioctl can support one or more cache invalidation requests in the array + * that has a total size of @req_len * @req_num. + */ +struct iommu_hwpt_invalidate { + __u32 size; + __u32 hwpt_id; + __aligned_u64 reqs_uptr; + __u32 req_type; + __u32 req_len; + __u32 req_num; + __u32 out_driver_error_code; +}; +#define IOMMU_HWPT_INVALIDATE _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HWPT_INVALIDATE) #endif