xref: /linux/drivers/gpu/drm/i915/gvt/page_track.c (revision bf4afc53b77aeaa48b5409da5c8da6bb4eff7f43)
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 
24 #include "gvt.h"
25 #include "i915_drv.h"
26 
27 /**
28  * intel_vgpu_find_page_track - find page track rcord of guest page
29  * @vgpu: a vGPU
30  * @gfn: the gfn of guest page
31  *
32  * Returns:
33  * A pointer to struct intel_vgpu_page_track if found, else NULL returned.
34  */
intel_vgpu_find_page_track(struct intel_vgpu * vgpu,unsigned long gfn)35 struct intel_vgpu_page_track *intel_vgpu_find_page_track(
36 		struct intel_vgpu *vgpu, unsigned long gfn)
37 {
38 	return radix_tree_lookup(&vgpu->page_track_tree, gfn);
39 }
40 
41 /**
42  * intel_vgpu_register_page_track - register a guest page to be tacked
43  * @vgpu: a vGPU
44  * @gfn: the gfn of guest page
45  * @handler: page track handler
46  * @priv: tracker private
47  *
48  * Returns:
49  * zero on success, negative error code if failed.
50  */
intel_vgpu_register_page_track(struct intel_vgpu * vgpu,unsigned long gfn,gvt_page_track_handler_t handler,void * priv)51 int intel_vgpu_register_page_track(struct intel_vgpu *vgpu, unsigned long gfn,
52 		gvt_page_track_handler_t handler, void *priv)
53 {
54 	struct intel_vgpu_page_track *track;
55 	int ret;
56 
57 	track = intel_vgpu_find_page_track(vgpu, gfn);
58 	if (track)
59 		return -EEXIST;
60 
61 	track = kzalloc_obj(*track);
62 	if (!track)
63 		return -ENOMEM;
64 
65 	track->handler = handler;
66 	track->priv_data = priv;
67 
68 	ret = radix_tree_insert(&vgpu->page_track_tree, gfn, track);
69 	if (ret) {
70 		kfree(track);
71 		return ret;
72 	}
73 
74 	return 0;
75 }
76 
77 /**
78  * intel_vgpu_unregister_page_track - unregister the tracked guest page
79  * @vgpu: a vGPU
80  * @gfn: the gfn of guest page
81  *
82  */
intel_vgpu_unregister_page_track(struct intel_vgpu * vgpu,unsigned long gfn)83 void intel_vgpu_unregister_page_track(struct intel_vgpu *vgpu,
84 		unsigned long gfn)
85 {
86 	struct intel_vgpu_page_track *track;
87 
88 	track = radix_tree_delete(&vgpu->page_track_tree, gfn);
89 	if (track) {
90 		if (track->tracked)
91 			intel_gvt_page_track_remove(vgpu, gfn);
92 		kfree(track);
93 	}
94 }
95 
96 /**
97  * intel_vgpu_enable_page_track - set write-protection on guest page
98  * @vgpu: a vGPU
99  * @gfn: the gfn of guest page
100  *
101  * Returns:
102  * zero on success, negative error code if failed.
103  */
intel_vgpu_enable_page_track(struct intel_vgpu * vgpu,unsigned long gfn)104 int intel_vgpu_enable_page_track(struct intel_vgpu *vgpu, unsigned long gfn)
105 {
106 	struct intel_vgpu_page_track *track;
107 	int ret;
108 
109 	track = intel_vgpu_find_page_track(vgpu, gfn);
110 	if (!track)
111 		return -ENXIO;
112 
113 	if (track->tracked)
114 		return 0;
115 
116 	ret = intel_gvt_page_track_add(vgpu, gfn);
117 	if (ret)
118 		return ret;
119 	track->tracked = true;
120 	return 0;
121 }
122 
123 /**
124  * intel_vgpu_disable_page_track - cancel write-protection on guest page
125  * @vgpu: a vGPU
126  * @gfn: the gfn of guest page
127  *
128  * Returns:
129  * zero on success, negative error code if failed.
130  */
intel_vgpu_disable_page_track(struct intel_vgpu * vgpu,unsigned long gfn)131 int intel_vgpu_disable_page_track(struct intel_vgpu *vgpu, unsigned long gfn)
132 {
133 	struct intel_vgpu_page_track *track;
134 	int ret;
135 
136 	track = intel_vgpu_find_page_track(vgpu, gfn);
137 	if (!track)
138 		return -ENXIO;
139 
140 	if (!track->tracked)
141 		return 0;
142 
143 	ret = intel_gvt_page_track_remove(vgpu, gfn);
144 	if (ret)
145 		return ret;
146 	track->tracked = false;
147 	return 0;
148 }
149 
150 /**
151  * intel_vgpu_page_track_handler - called when write to write-protected page
152  * @vgpu: a vGPU
153  * @gpa: the gpa of this write
154  * @data: the writed data
155  * @bytes: the length of this write
156  *
157  * Returns:
158  * zero on success, negative error code if failed.
159  */
intel_vgpu_page_track_handler(struct intel_vgpu * vgpu,u64 gpa,void * data,unsigned int bytes)160 int intel_vgpu_page_track_handler(struct intel_vgpu *vgpu, u64 gpa,
161 		void *data, unsigned int bytes)
162 {
163 	struct intel_vgpu_page_track *page_track;
164 	int ret = 0;
165 
166 	page_track = intel_vgpu_find_page_track(vgpu, gpa >> PAGE_SHIFT);
167 	if (!page_track)
168 		return -ENXIO;
169 
170 	if (unlikely(vgpu->failsafe)) {
171 		/* Remove write protection to prevent future traps. */
172 		intel_gvt_page_track_remove(vgpu, gpa >> PAGE_SHIFT);
173 	} else {
174 		ret = page_track->handler(page_track, gpa, data, bytes);
175 		if (ret)
176 			gvt_err("guest page write error, gpa %llx\n", gpa);
177 	}
178 
179 	return ret;
180 }
181