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author | Jason Gunthorpe <jgg@nvidia.com> | 2022-11-29 16:29:29 -0400 |
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committer | Jason Gunthorpe <jgg@nvidia.com> | 2022-11-30 20:16:49 -0400 |
commit | 2ff4bed7fee72ba1abfcff5f11ae8f8e570353f2 (patch) | |
tree | e932c21eef44174131e88a1f8cc5ffc5175589fb /include | |
parent | 658234de0d2ed3a1b86d793f4772e38a2e039b35 (diff) | |
download | linux-2ff4bed7fee72ba1abfcff5f11ae8f8e570353f2.tar.bz2 |
iommufd: File descriptor, context, kconfig and makefiles
This is the basic infrastructure of a new miscdevice to hold the iommufd
IOCTL API.
It provides:
- A miscdevice to create file descriptors to run the IOCTL interface over
- A table based ioctl dispatch and centralized extendable pre-validation
step
- An xarray mapping userspace ID's to kernel objects. The design has
multiple inter-related objects held within in a single IOMMUFD fd
- A simple usage count to build a graph of object relations and protect
against hostile userspace racing ioctls
The only IOCTL provided in this patch is the generic 'destroy any object
by handle' operation.
Link: https://lore.kernel.org/r/6-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/iommufd.h | 31 | ||||
-rw-r--r-- | include/uapi/linux/iommufd.h | 55 |
2 files changed, 86 insertions, 0 deletions
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h new file mode 100644 index 000000000000..d1817472c273 --- /dev/null +++ b/include/linux/iommufd.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2021 Intel Corporation + * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES + */ +#ifndef __LINUX_IOMMUFD_H +#define __LINUX_IOMMUFD_H + +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/err.h> + +struct iommufd_ctx; +struct file; + +void iommufd_ctx_get(struct iommufd_ctx *ictx); + +#if IS_ENABLED(CONFIG_IOMMUFD) +struct iommufd_ctx *iommufd_ctx_from_file(struct file *file); +void iommufd_ctx_put(struct iommufd_ctx *ictx); +#else /* !CONFIG_IOMMUFD */ +static inline struct iommufd_ctx *iommufd_ctx_from_file(struct file *file) +{ + return ERR_PTR(-EOPNOTSUPP); +} + +static inline void iommufd_ctx_put(struct iommufd_ctx *ictx) +{ +} +#endif /* CONFIG_IOMMUFD */ +#endif diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h new file mode 100644 index 000000000000..37de92f0534b --- /dev/null +++ b/include/uapi/linux/iommufd.h @@ -0,0 +1,55 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES. + */ +#ifndef _UAPI_IOMMUFD_H +#define _UAPI_IOMMUFD_H + +#include <linux/types.h> +#include <linux/ioctl.h> + +#define IOMMUFD_TYPE (';') + +/** + * DOC: General ioctl format + * + * The ioctl interface follows a general format to allow for extensibility. Each + * ioctl is passed in a structure pointer as the argument providing the size of + * the structure in the first u32. The kernel checks that any structure space + * beyond what it understands is 0. This allows userspace to use the backward + * compatible portion while consistently using the newer, larger, structures. + * + * ioctls use a standard meaning for common errnos: + * + * - ENOTTY: The IOCTL number itself is not supported at all + * - E2BIG: The IOCTL number is supported, but the provided structure has + * non-zero in a part the kernel does not understand. + * - EOPNOTSUPP: The IOCTL number is supported, and the structure is + * understood, however a known field has a value the kernel does not + * understand or support. + * - EINVAL: Everything about the IOCTL was understood, but a field is not + * correct. + * - ENOENT: An ID or IOVA provided does not exist. + * - ENOMEM: Out of memory. + * - EOVERFLOW: Mathematics overflowed. + * + * As well as additional errnos, within specific ioctls. + */ +enum { + IOMMUFD_CMD_BASE = 0x80, + IOMMUFD_CMD_DESTROY = IOMMUFD_CMD_BASE, +}; + +/** + * struct iommu_destroy - ioctl(IOMMU_DESTROY) + * @size: sizeof(struct iommu_destroy) + * @id: iommufd object ID to destroy. Can by any destroyable object type. + * + * Destroy any object held within iommufd. + */ +struct iommu_destroy { + __u32 size; + __u32 id; +}; +#define IOMMU_DESTROY _IO(IOMMUFD_TYPE, IOMMUFD_CMD_DESTROY) + +#endif |