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 */
34struct 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 */
50int 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 */
82void 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 */
103int 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 */
130int 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 */
159int 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