xref: /linux/drivers/gpu/drm/i915/gvt/page_track.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 /*
2  * Copyright(c) 2011-2017 Intel Corporation. All rights reserved.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21  * SOFTWARE.
22  */
23 #include "i915_drv.h"
24 #include "gvt.h"
25 
26 /**
27  * intel_vgpu_find_page_track - find page track rcord of guest page
28  * @vgpu: a vGPU
29  * @gfn: the gfn of guest page
30  *
31  * Returns:
32  * A pointer to struct intel_vgpu_page_track if found, else NULL returned.
33  */
34 struct intel_vgpu_page_track *intel_vgpu_find_page_track(
35 		struct intel_vgpu *vgpu, unsigned long gfn)
36 {
37 	return radix_tree_lookup(&vgpu->page_track_tree, gfn);
38 }
39 
40 /**
41  * intel_vgpu_register_page_track - register a guest page to be tacked
42  * @vgpu: a vGPU
43  * @gfn: the gfn of guest page
44  * @handler: page track handler
45  * @priv: tracker private
46  *
47  * Returns:
48  * zero on success, negative error code if failed.
49  */
50 int intel_vgpu_register_page_track(struct intel_vgpu *vgpu, unsigned long gfn,
51 		gvt_page_track_handler_t handler, void *priv)
52 {
53 	struct intel_vgpu_page_track *track;
54 	int ret;
55 
56 	track = intel_vgpu_find_page_track(vgpu, gfn);
57 	if (track)
58 		return -EEXIST;
59 
60 	track = kzalloc(sizeof(*track), GFP_KERNEL);
61 	if (!track)
62 		return -ENOMEM;
63 
64 	track->handler = handler;
65 	track->priv_data = priv;
66 
67 	ret = radix_tree_insert(&vgpu->page_track_tree, gfn, track);
68 	if (ret) {
69 		kfree(track);
70 		return ret;
71 	}
72 
73 	return 0;
74 }
75 
76 /**
77  * intel_vgpu_unregister_page_track - unregister the tracked guest page
78  * @vgpu: a vGPU
79  * @gfn: the gfn of guest page
80  *
81  */
82 void intel_vgpu_unregister_page_track(struct intel_vgpu *vgpu,
83 		unsigned long gfn)
84 {
85 	struct intel_vgpu_page_track *track;
86 
87 	track = radix_tree_delete(&vgpu->page_track_tree, gfn);
88 	if (track) {
89 		if (track->tracked)
90 			intel_gvt_page_track_remove(vgpu, gfn);
91 		kfree(track);
92 	}
93 }
94 
95 /**
96  * intel_vgpu_enable_page_track - set write-protection on guest page
97  * @vgpu: a vGPU
98  * @gfn: the gfn of guest page
99  *
100  * Returns:
101  * zero on success, negative error code if failed.
102  */
103 int intel_vgpu_enable_page_track(struct intel_vgpu *vgpu, unsigned long gfn)
104 {
105 	struct intel_vgpu_page_track *track;
106 	int ret;
107 
108 	track = intel_vgpu_find_page_track(vgpu, gfn);
109 	if (!track)
110 		return -ENXIO;
111 
112 	if (track->tracked)
113 		return 0;
114 
115 	ret = intel_gvt_page_track_add(vgpu, gfn);
116 	if (ret)
117 		return ret;
118 	track->tracked = true;
119 	return 0;
120 }
121 
122 /**
123  * intel_vgpu_disable_page_track - cancel write-protection on guest page
124  * @vgpu: a vGPU
125  * @gfn: the gfn of guest page
126  *
127  * Returns:
128  * zero on success, negative error code if failed.
129  */
130 int intel_vgpu_disable_page_track(struct intel_vgpu *vgpu, unsigned long gfn)
131 {
132 	struct intel_vgpu_page_track *track;
133 	int ret;
134 
135 	track = intel_vgpu_find_page_track(vgpu, gfn);
136 	if (!track)
137 		return -ENXIO;
138 
139 	if (!track->tracked)
140 		return 0;
141 
142 	ret = intel_gvt_page_track_remove(vgpu, gfn);
143 	if (ret)
144 		return ret;
145 	track->tracked = false;
146 	return 0;
147 }
148 
149 /**
150  * intel_vgpu_page_track_handler - called when write to write-protected page
151  * @vgpu: a vGPU
152  * @gpa: the gpa of this write
153  * @data: the writed data
154  * @bytes: the length of this write
155  *
156  * Returns:
157  * zero on success, negative error code if failed.
158  */
159 int intel_vgpu_page_track_handler(struct intel_vgpu *vgpu, u64 gpa,
160 		void *data, unsigned int bytes)
161 {
162 	struct intel_vgpu_page_track *page_track;
163 	int ret = 0;
164 
165 	page_track = intel_vgpu_find_page_track(vgpu, gpa >> PAGE_SHIFT);
166 	if (!page_track)
167 		return -ENXIO;
168 
169 	if (unlikely(vgpu->failsafe)) {
170 		/* Remove write protection to prevent furture traps. */
171 		intel_gvt_page_track_remove(vgpu, gpa >> PAGE_SHIFT);
172 	} else {
173 		ret = page_track->handler(page_track, gpa, data, bytes);
174 		if (ret)
175 			gvt_err("guest page write error, gpa %llx\n", gpa);
176 	}
177 
178 	return ret;
179 }
180