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cf9d2890 YZ |
1 | /* |
2 | * Copyright(c) 2011-2015 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 "intel_drv.h" | |
25 | #include "i915_vgpu.h" | |
26 | ||
27 | /** | |
28 | * DOC: Intel GVT-g guest support | |
29 | * | |
30 | * Intel GVT-g is a graphics virtualization technology which shares the | |
31 | * GPU among multiple virtual machines on a time-sharing basis. Each | |
32 | * virtual machine is presented a virtual GPU (vGPU), which has equivalent | |
33 | * features as the underlying physical GPU (pGPU), so i915 driver can run | |
34 | * seamlessly in a virtual machine. This file provides vGPU specific | |
35 | * optimizations when running in a virtual machine, to reduce the complexity | |
36 | * of vGPU emulation and to improve the overall performance. | |
37 | * | |
38 | * A primary function introduced here is so-called "address space ballooning" | |
39 | * technique. Intel GVT-g partitions global graphics memory among multiple VMs, | |
40 | * so each VM can directly access a portion of the memory without hypervisor's | |
41 | * intervention, e.g. filling textures or queuing commands. However with the | |
42 | * partitioning an unmodified i915 driver would assume a smaller graphics | |
43 | * memory starting from address ZERO, then requires vGPU emulation module to | |
44 | * translate the graphics address between 'guest view' and 'host view', for | |
45 | * all registers and command opcodes which contain a graphics memory address. | |
46 | * To reduce the complexity, Intel GVT-g introduces "address space ballooning", | |
47 | * by telling the exact partitioning knowledge to each guest i915 driver, which | |
48 | * then reserves and prevents non-allocated portions from allocation. Thus vGPU | |
49 | * emulation module only needs to scan and validate graphics addresses without | |
50 | * complexity of address translation. | |
51 | * | |
52 | */ | |
53 | ||
54 | /** | |
55 | * i915_check_vgpu - detect virtual GPU | |
14bb2c11 | 56 | * @dev_priv: i915 device private |
cf9d2890 YZ |
57 | * |
58 | * This function is called at the initialization stage, to detect whether | |
59 | * running on a vGPU. | |
60 | */ | |
dc97997a | 61 | void i915_check_vgpu(struct drm_i915_private *dev_priv) |
cf9d2890 | 62 | { |
cf9d2890 YZ |
63 | uint64_t magic; |
64 | uint32_t version; | |
65 | ||
66 | BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE); | |
67 | ||
75aa3f63 | 68 | magic = __raw_i915_read64(dev_priv, vgtif_reg(magic)); |
cf9d2890 YZ |
69 | if (magic != VGT_MAGIC) |
70 | return; | |
71 | ||
72 | version = INTEL_VGT_IF_VERSION_ENCODE( | |
75aa3f63 VS |
73 | __raw_i915_read16(dev_priv, vgtif_reg(version_major)), |
74 | __raw_i915_read16(dev_priv, vgtif_reg(version_minor))); | |
cf9d2890 YZ |
75 | if (version != INTEL_VGT_IF_VERSION) { |
76 | DRM_INFO("VGT interface version mismatch!\n"); | |
77 | return; | |
78 | } | |
79 | ||
80 | dev_priv->vgpu.active = true; | |
81 | DRM_INFO("Virtual GPU for Intel GVT-g detected.\n"); | |
82 | } | |
5dda8fa3 YZ |
83 | |
84 | struct _balloon_info_ { | |
85 | /* | |
86 | * There are up to 2 regions per mappable/unmappable graphic | |
87 | * memory that might be ballooned. Here, index 0/1 is for mappable | |
88 | * graphic memory, 2/3 for unmappable graphic memory. | |
89 | */ | |
90 | struct drm_mm_node space[4]; | |
91 | }; | |
92 | ||
93 | static struct _balloon_info_ bl_info; | |
94 | ||
95 | /** | |
96 | * intel_vgt_deballoon - deballoon reserved graphics address trunks | |
62f90b38 | 97 | * @dev_priv: i915 device private data |
5dda8fa3 YZ |
98 | * |
99 | * This function is called to deallocate the ballooned-out graphic memory, when | |
100 | * driver is unloaded or when ballooning fails. | |
101 | */ | |
b02d22a3 | 102 | void intel_vgt_deballoon(struct drm_i915_private *dev_priv) |
5dda8fa3 YZ |
103 | { |
104 | int i; | |
105 | ||
b02d22a3 ZW |
106 | if (!intel_vgpu_active(dev_priv)) |
107 | return; | |
108 | ||
5dda8fa3 YZ |
109 | DRM_DEBUG("VGT deballoon.\n"); |
110 | ||
111 | for (i = 0; i < 4; i++) { | |
112 | if (bl_info.space[i].allocated) | |
113 | drm_mm_remove_node(&bl_info.space[i]); | |
114 | } | |
115 | ||
116 | memset(&bl_info, 0, sizeof(bl_info)); | |
117 | } | |
118 | ||
119 | static int vgt_balloon_space(struct drm_mm *mm, | |
120 | struct drm_mm_node *node, | |
121 | unsigned long start, unsigned long end) | |
122 | { | |
123 | unsigned long size = end - start; | |
124 | ||
125 | if (start == end) | |
126 | return -EINVAL; | |
127 | ||
128 | DRM_INFO("balloon space: range [ 0x%lx - 0x%lx ] %lu KiB.\n", | |
129 | start, end, size / 1024); | |
130 | ||
131 | node->start = start; | |
132 | node->size = size; | |
133 | ||
134 | return drm_mm_reserve_node(mm, node); | |
135 | } | |
136 | ||
137 | /** | |
138 | * intel_vgt_balloon - balloon out reserved graphics address trunks | |
62f90b38 | 139 | * @dev_priv: i915 device private data |
5dda8fa3 YZ |
140 | * |
141 | * This function is called at the initialization stage, to balloon out the | |
142 | * graphic address space allocated to other vGPUs, by marking these spaces as | |
143 | * reserved. The ballooning related knowledge(starting address and size of | |
144 | * the mappable/unmappable graphic memory) is described in the vgt_if structure | |
145 | * in a reserved mmio range. | |
146 | * | |
147 | * To give an example, the drawing below depicts one typical scenario after | |
148 | * ballooning. Here the vGPU1 has 2 pieces of graphic address spaces ballooned | |
149 | * out each for the mappable and the non-mappable part. From the vGPU1 point of | |
150 | * view, the total size is the same as the physical one, with the start address | |
151 | * of its graphic space being zero. Yet there are some portions ballooned out( | |
152 | * the shadow part, which are marked as reserved by drm allocator). From the | |
153 | * host point of view, the graphic address space is partitioned by multiple | |
da5335b8 | 154 | * vGPUs in different VMs. :: |
5dda8fa3 | 155 | * |
62cacc79 DV |
156 | * vGPU1 view Host view |
157 | * 0 ------> +-----------+ +-----------+ | |
158 | * ^ |###########| | vGPU3 | | |
159 | * | |###########| +-----------+ | |
160 | * | |###########| | vGPU2 | | |
161 | * | +-----------+ +-----------+ | |
162 | * mappable GM | available | ==> | vGPU1 | | |
163 | * | +-----------+ +-----------+ | |
164 | * | |###########| | | | |
165 | * v |###########| | Host | | |
166 | * +=======+===========+ +===========+ | |
167 | * ^ |###########| | vGPU3 | | |
168 | * | |###########| +-----------+ | |
169 | * | |###########| | vGPU2 | | |
170 | * | +-----------+ +-----------+ | |
171 | * unmappable GM | available | ==> | vGPU1 | | |
172 | * | +-----------+ +-----------+ | |
173 | * | |###########| | | | |
174 | * | |###########| | Host | | |
175 | * v |###########| | | | |
176 | * total GM size ------> +-----------+ +-----------+ | |
5dda8fa3 YZ |
177 | * |
178 | * Returns: | |
179 | * zero on success, non-zero if configuration invalid or ballooning failed | |
180 | */ | |
b02d22a3 | 181 | int intel_vgt_balloon(struct drm_i915_private *dev_priv) |
5dda8fa3 | 182 | { |
72e96d64 JL |
183 | struct i915_ggtt *ggtt = &dev_priv->ggtt; |
184 | unsigned long ggtt_end = ggtt->base.start + ggtt->base.total; | |
5dda8fa3 YZ |
185 | |
186 | unsigned long mappable_base, mappable_size, mappable_end; | |
187 | unsigned long unmappable_base, unmappable_size, unmappable_end; | |
188 | int ret; | |
189 | ||
b02d22a3 ZW |
190 | if (!intel_vgpu_active(dev_priv)) |
191 | return 0; | |
192 | ||
5dda8fa3 YZ |
193 | mappable_base = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.base)); |
194 | mappable_size = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.size)); | |
195 | unmappable_base = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.base)); | |
196 | unmappable_size = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.size)); | |
197 | ||
198 | mappable_end = mappable_base + mappable_size; | |
199 | unmappable_end = unmappable_base + unmappable_size; | |
200 | ||
201 | DRM_INFO("VGT ballooning configuration:\n"); | |
202 | DRM_INFO("Mappable graphic memory: base 0x%lx size %ldKiB\n", | |
203 | mappable_base, mappable_size / 1024); | |
204 | DRM_INFO("Unmappable graphic memory: base 0x%lx size %ldKiB\n", | |
205 | unmappable_base, unmappable_size / 1024); | |
206 | ||
72e96d64 JL |
207 | if (mappable_base < ggtt->base.start || |
208 | mappable_end > ggtt->mappable_end || | |
209 | unmappable_base < ggtt->mappable_end || | |
210 | unmappable_end > ggtt_end) { | |
5dda8fa3 YZ |
211 | DRM_ERROR("Invalid ballooning configuration!\n"); |
212 | return -EINVAL; | |
213 | } | |
214 | ||
215 | /* Unmappable graphic memory ballooning */ | |
72e96d64 JL |
216 | if (unmappable_base > ggtt->mappable_end) { |
217 | ret = vgt_balloon_space(&ggtt->base.mm, | |
5dda8fa3 | 218 | &bl_info.space[2], |
72e96d64 | 219 | ggtt->mappable_end, |
5dda8fa3 YZ |
220 | unmappable_base); |
221 | ||
222 | if (ret) | |
223 | goto err; | |
224 | } | |
225 | ||
226 | /* | |
227 | * No need to partition out the last physical page, | |
228 | * because it is reserved to the guard page. | |
229 | */ | |
72e96d64 JL |
230 | if (unmappable_end < ggtt_end - PAGE_SIZE) { |
231 | ret = vgt_balloon_space(&ggtt->base.mm, | |
5dda8fa3 YZ |
232 | &bl_info.space[3], |
233 | unmappable_end, | |
72e96d64 | 234 | ggtt_end - PAGE_SIZE); |
5dda8fa3 YZ |
235 | if (ret) |
236 | goto err; | |
237 | } | |
238 | ||
239 | /* Mappable graphic memory ballooning */ | |
72e96d64 JL |
240 | if (mappable_base > ggtt->base.start) { |
241 | ret = vgt_balloon_space(&ggtt->base.mm, | |
5dda8fa3 | 242 | &bl_info.space[0], |
72e96d64 | 243 | ggtt->base.start, mappable_base); |
5dda8fa3 YZ |
244 | |
245 | if (ret) | |
246 | goto err; | |
247 | } | |
248 | ||
72e96d64 JL |
249 | if (mappable_end < ggtt->mappable_end) { |
250 | ret = vgt_balloon_space(&ggtt->base.mm, | |
5dda8fa3 YZ |
251 | &bl_info.space[1], |
252 | mappable_end, | |
72e96d64 | 253 | ggtt->mappable_end); |
5dda8fa3 YZ |
254 | |
255 | if (ret) | |
256 | goto err; | |
257 | } | |
258 | ||
259 | DRM_INFO("VGT balloon successfully\n"); | |
260 | return 0; | |
261 | ||
262 | err: | |
263 | DRM_ERROR("VGT balloon fail\n"); | |
b02d22a3 | 264 | intel_vgt_deballoon(dev_priv); |
5dda8fa3 YZ |
265 | return ret; |
266 | } |