tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES
4 */
5#include <linux/vfio.h>
6#include <linux/iommufd.h>
7
8#include "vfio.h"
9
10MODULE_IMPORT_NS(IOMMUFD);
11MODULE_IMPORT_NS(IOMMUFD_VFIO);
12
13int vfio_iommufd_bind(struct vfio_device *vdev, struct iommufd_ctx *ictx)
14{
15 u32 ioas_id;
16 u32 device_id;
17 int ret;
18
19 lockdep_assert_held(&vdev->dev_set->lock);
20
21 if (vfio_device_is_noiommu(vdev)) {
22 if (!capable(CAP_SYS_RAWIO))
23 return -EPERM;
24
25 /*
26 * Require no compat ioas to be assigned to proceed. The basic
27 * statement is that the user cannot have done something that
28 * implies they expected translation to exist
29 */
30 if (!iommufd_vfio_compat_ioas_get_id(ictx, &ioas_id))
31 return -EPERM;
32 return 0;
33 }
34
35 /*
36 * If the driver doesn't provide this op then it means the device does
37 * not do DMA at all. So nothing to do.
38 */
39 if (!vdev->ops->bind_iommufd)
40 return 0;
41
42 ret = vdev->ops->bind_iommufd(vdev, ictx, &device_id);
43 if (ret)
44 return ret;
45
46 ret = iommufd_vfio_compat_ioas_get_id(ictx, &ioas_id);
47 if (ret)
48 goto err_unbind;
49 ret = vdev->ops->attach_ioas(vdev, &ioas_id);
50 if (ret)
51 goto err_unbind;
52
53 /*
54 * The legacy path has no way to return the device id or the selected
55 * pt_id
56 */
57 return 0;
58
59err_unbind:
60 if (vdev->ops->unbind_iommufd)
61 vdev->ops->unbind_iommufd(vdev);
62 return ret;
63}
64
65void vfio_iommufd_unbind(struct vfio_device *vdev)
66{
67 lockdep_assert_held(&vdev->dev_set->lock);
68
69 if (vfio_device_is_noiommu(vdev))
70 return;
71
72 if (vdev->ops->unbind_iommufd)
73 vdev->ops->unbind_iommufd(vdev);
74}
75
76/*
77 * The physical standard ops mean that the iommufd_device is bound to the
78 * physical device vdev->dev that was provided to vfio_init_group_dev(). Drivers
79 * using this ops set should call vfio_register_group_dev()
80 */
81int vfio_iommufd_physical_bind(struct vfio_device *vdev,
82 struct iommufd_ctx *ictx, u32 *out_device_id)
83{
84 struct iommufd_device *idev;
85
86 idev = iommufd_device_bind(ictx, vdev->dev, out_device_id);
87 if (IS_ERR(idev))
88 return PTR_ERR(idev);
89 vdev->iommufd_device = idev;
90 return 0;
91}
92EXPORT_SYMBOL_GPL(vfio_iommufd_physical_bind);
93
94void vfio_iommufd_physical_unbind(struct vfio_device *vdev)
95{
96 lockdep_assert_held(&vdev->dev_set->lock);
97
98 if (vdev->iommufd_attached) {
99 iommufd_device_detach(vdev->iommufd_device);
100 vdev->iommufd_attached = false;
101 }
102 iommufd_device_unbind(vdev->iommufd_device);
103 vdev->iommufd_device = NULL;
104}
105EXPORT_SYMBOL_GPL(vfio_iommufd_physical_unbind);
106
107int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
108{
109 int rc;
110
111 rc = iommufd_device_attach(vdev->iommufd_device, pt_id);
112 if (rc)
113 return rc;
114 vdev->iommufd_attached = true;
115 return 0;
116}
117EXPORT_SYMBOL_GPL(vfio_iommufd_physical_attach_ioas);
118
119/*
120 * The emulated standard ops mean that vfio_device is going to use the
121 * "mdev path" and will call vfio_pin_pages()/vfio_dma_rw(). Drivers using this
122 * ops set should call vfio_register_emulated_iommu_dev().
123 */
124
125static void vfio_emulated_unmap(void *data, unsigned long iova,
126 unsigned long length)
127{
128 struct vfio_device *vdev = data;
129
130 vdev->ops->dma_unmap(vdev, iova, length);
131}
132
133static const struct iommufd_access_ops vfio_user_ops = {
134 .needs_pin_pages = 1,
135 .unmap = vfio_emulated_unmap,
136};
137
138int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
139 struct iommufd_ctx *ictx, u32 *out_device_id)
140{
141 lockdep_assert_held(&vdev->dev_set->lock);
142
143 vdev->iommufd_ictx = ictx;
144 iommufd_ctx_get(ictx);
145 return 0;
146}
147EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_bind);
148
149void vfio_iommufd_emulated_unbind(struct vfio_device *vdev)
150{
151 lockdep_assert_held(&vdev->dev_set->lock);
152
153 if (vdev->iommufd_access) {
154 iommufd_access_destroy(vdev->iommufd_access);
155 vdev->iommufd_access = NULL;
156 }
157 iommufd_ctx_put(vdev->iommufd_ictx);
158 vdev->iommufd_ictx = NULL;
159}
160EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_unbind);
161
162int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
163{
164 struct iommufd_access *user;
165
166 lockdep_assert_held(&vdev->dev_set->lock);
167
168 user = iommufd_access_create(vdev->iommufd_ictx, *pt_id, &vfio_user_ops,
169 vdev);
170 if (IS_ERR(user))
171 return PTR_ERR(user);
172 vdev->iommufd_access = user;
173 return 0;
174}
175EXPORT_SYMBOL_GPL(vfio_iommufd_emulated_attach_ioas);