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 "i915_drv.h" |
25 | #include "i915_pvinfo.h" |
26 | #include "i915_vgpu.h" |
27 | |
28 | /** |
29 | * DOC: Intel GVT-g guest support |
30 | * |
31 | * Intel GVT-g is a graphics virtualization technology which shares the |
32 | * GPU among multiple virtual machines on a time-sharing basis. Each |
33 | * virtual machine is presented a virtual GPU (vGPU), which has equivalent |
34 | * features as the underlying physical GPU (pGPU), so i915 driver can run |
35 | * seamlessly in a virtual machine. This file provides vGPU specific |
36 | * optimizations when running in a virtual machine, to reduce the complexity |
37 | * of vGPU emulation and to improve the overall performance. |
38 | * |
39 | * A primary function introduced here is so-called "address space ballooning" |
40 | * technique. Intel GVT-g partitions global graphics memory among multiple VMs, |
41 | * so each VM can directly access a portion of the memory without hypervisor's |
42 | * intervention, e.g. filling textures or queuing commands. However with the |
43 | * partitioning an unmodified i915 driver would assume a smaller graphics |
44 | * memory starting from address ZERO, then requires vGPU emulation module to |
45 | * translate the graphics address between 'guest view' and 'host view', for |
46 | * all registers and command opcodes which contain a graphics memory address. |
47 | * To reduce the complexity, Intel GVT-g introduces "address space ballooning", |
48 | * by telling the exact partitioning knowledge to each guest i915 driver, which |
49 | * then reserves and prevents non-allocated portions from allocation. Thus vGPU |
50 | * emulation module only needs to scan and validate graphics addresses without |
51 | * complexity of address translation. |
52 | * |
53 | */ |
54 | |
55 | /** |
56 | * intel_vgpu_detect - detect virtual GPU |
57 | * @dev_priv: i915 device private |
58 | * |
59 | * This function is called at the initialization stage, to detect whether |
60 | * running on a vGPU. |
61 | */ |
62 | void intel_vgpu_detect(struct drm_i915_private *dev_priv) |
63 | { |
64 | struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev); |
65 | u64 magic; |
66 | u16 version_major; |
67 | void __iomem *shared_area; |
68 | |
69 | BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE); |
70 | |
71 | /* |
72 | * This is called before we setup the main MMIO BAR mappings used via |
73 | * the uncore structure, so we need to access the BAR directly. Since |
74 | * we do not support VGT on older gens, return early so we don't have |
75 | * to consider differently numbered or sized MMIO bars |
76 | */ |
77 | if (GRAPHICS_VER(dev_priv) < 6) |
78 | return; |
79 | |
80 | shared_area = pci_iomap_range(dev: pdev, bar: 0, VGT_PVINFO_PAGE, VGT_PVINFO_SIZE); |
81 | if (!shared_area) { |
82 | drm_err(&dev_priv->drm, |
83 | "failed to map MMIO bar to check for VGT\n" ); |
84 | return; |
85 | } |
86 | |
87 | magic = readq(addr: shared_area + vgtif_offset(magic)); |
88 | if (magic != VGT_MAGIC) |
89 | goto out; |
90 | |
91 | version_major = readw(addr: shared_area + vgtif_offset(version_major)); |
92 | if (version_major < VGT_VERSION_MAJOR) { |
93 | drm_info(&dev_priv->drm, "VGT interface version mismatch!\n" ); |
94 | goto out; |
95 | } |
96 | |
97 | dev_priv->vgpu.caps = readl(addr: shared_area + vgtif_offset(vgt_caps)); |
98 | |
99 | dev_priv->vgpu.active = true; |
100 | mutex_init(&dev_priv->vgpu.lock); |
101 | drm_info(&dev_priv->drm, "Virtual GPU for Intel GVT-g detected.\n" ); |
102 | |
103 | out: |
104 | pci_iounmap(dev: pdev, shared_area); |
105 | } |
106 | |
107 | void intel_vgpu_register(struct drm_i915_private *i915) |
108 | { |
109 | /* |
110 | * Notify a valid surface after modesetting, when running inside a VM. |
111 | */ |
112 | if (intel_vgpu_active(i915)) |
113 | intel_uncore_write(uncore: &i915->uncore, vgtif_reg(display_ready), |
114 | VGT_DRV_DISPLAY_READY); |
115 | } |
116 | |
117 | bool intel_vgpu_active(struct drm_i915_private *dev_priv) |
118 | { |
119 | return dev_priv->vgpu.active; |
120 | } |
121 | |
122 | bool intel_vgpu_has_full_ppgtt(struct drm_i915_private *dev_priv) |
123 | { |
124 | return dev_priv->vgpu.caps & VGT_CAPS_FULL_PPGTT; |
125 | } |
126 | |
127 | bool intel_vgpu_has_hwsp_emulation(struct drm_i915_private *dev_priv) |
128 | { |
129 | return dev_priv->vgpu.caps & VGT_CAPS_HWSP_EMULATION; |
130 | } |
131 | |
132 | bool intel_vgpu_has_huge_gtt(struct drm_i915_private *dev_priv) |
133 | { |
134 | return dev_priv->vgpu.caps & VGT_CAPS_HUGE_GTT; |
135 | } |
136 | |
137 | struct _balloon_info_ { |
138 | /* |
139 | * There are up to 2 regions per mappable/unmappable graphic |
140 | * memory that might be ballooned. Here, index 0/1 is for mappable |
141 | * graphic memory, 2/3 for unmappable graphic memory. |
142 | */ |
143 | struct drm_mm_node space[4]; |
144 | }; |
145 | |
146 | static struct _balloon_info_ bl_info; |
147 | |
148 | static void vgt_deballoon_space(struct i915_ggtt *ggtt, |
149 | struct drm_mm_node *node) |
150 | { |
151 | struct drm_i915_private *dev_priv = ggtt->vm.i915; |
152 | if (!drm_mm_node_allocated(node)) |
153 | return; |
154 | |
155 | drm_dbg(&dev_priv->drm, |
156 | "deballoon space: range [0x%llx - 0x%llx] %llu KiB.\n" , |
157 | node->start, |
158 | node->start + node->size, |
159 | node->size / 1024); |
160 | |
161 | ggtt->vm.reserved -= node->size; |
162 | drm_mm_remove_node(node); |
163 | } |
164 | |
165 | /** |
166 | * intel_vgt_deballoon - deballoon reserved graphics address trunks |
167 | * @ggtt: the global GGTT from which we reserved earlier |
168 | * |
169 | * This function is called to deallocate the ballooned-out graphic memory, when |
170 | * driver is unloaded or when ballooning fails. |
171 | */ |
172 | void intel_vgt_deballoon(struct i915_ggtt *ggtt) |
173 | { |
174 | struct drm_i915_private *dev_priv = ggtt->vm.i915; |
175 | int i; |
176 | |
177 | if (!intel_vgpu_active(dev_priv: ggtt->vm.i915)) |
178 | return; |
179 | |
180 | drm_dbg(&dev_priv->drm, "VGT deballoon.\n" ); |
181 | |
182 | for (i = 0; i < 4; i++) |
183 | vgt_deballoon_space(ggtt, node: &bl_info.space[i]); |
184 | } |
185 | |
186 | static int vgt_balloon_space(struct i915_ggtt *ggtt, |
187 | struct drm_mm_node *node, |
188 | unsigned long start, unsigned long end) |
189 | { |
190 | struct drm_i915_private *dev_priv = ggtt->vm.i915; |
191 | unsigned long size = end - start; |
192 | int ret; |
193 | |
194 | if (start >= end) |
195 | return -EINVAL; |
196 | |
197 | drm_info(&dev_priv->drm, |
198 | "balloon space: range [ 0x%lx - 0x%lx ] %lu KiB.\n" , |
199 | start, end, size / 1024); |
200 | ret = i915_gem_gtt_reserve(vm: &ggtt->vm, NULL, node, |
201 | size, offset: start, I915_COLOR_UNEVICTABLE, |
202 | flags: 0); |
203 | if (!ret) |
204 | ggtt->vm.reserved += size; |
205 | |
206 | return ret; |
207 | } |
208 | |
209 | /** |
210 | * intel_vgt_balloon - balloon out reserved graphics address trunks |
211 | * @ggtt: the global GGTT from which to reserve |
212 | * |
213 | * This function is called at the initialization stage, to balloon out the |
214 | * graphic address space allocated to other vGPUs, by marking these spaces as |
215 | * reserved. The ballooning related knowledge(starting address and size of |
216 | * the mappable/unmappable graphic memory) is described in the vgt_if structure |
217 | * in a reserved mmio range. |
218 | * |
219 | * To give an example, the drawing below depicts one typical scenario after |
220 | * ballooning. Here the vGPU1 has 2 pieces of graphic address spaces ballooned |
221 | * out each for the mappable and the non-mappable part. From the vGPU1 point of |
222 | * view, the total size is the same as the physical one, with the start address |
223 | * of its graphic space being zero. Yet there are some portions ballooned out( |
224 | * the shadow part, which are marked as reserved by drm allocator). From the |
225 | * host point of view, the graphic address space is partitioned by multiple |
226 | * vGPUs in different VMs. :: |
227 | * |
228 | * vGPU1 view Host view |
229 | * 0 ------> +-----------+ +-----------+ |
230 | * ^ |###########| | vGPU3 | |
231 | * | |###########| +-----------+ |
232 | * | |###########| | vGPU2 | |
233 | * | +-----------+ +-----------+ |
234 | * mappable GM | available | ==> | vGPU1 | |
235 | * | +-----------+ +-----------+ |
236 | * | |###########| | | |
237 | * v |###########| | Host | |
238 | * +=======+===========+ +===========+ |
239 | * ^ |###########| | vGPU3 | |
240 | * | |###########| +-----------+ |
241 | * | |###########| | vGPU2 | |
242 | * | +-----------+ +-----------+ |
243 | * unmappable GM | available | ==> | vGPU1 | |
244 | * | +-----------+ +-----------+ |
245 | * | |###########| | | |
246 | * | |###########| | Host | |
247 | * v |###########| | | |
248 | * total GM size ------> +-----------+ +-----------+ |
249 | * |
250 | * Returns: |
251 | * zero on success, non-zero if configuration invalid or ballooning failed |
252 | */ |
253 | int intel_vgt_balloon(struct i915_ggtt *ggtt) |
254 | { |
255 | struct drm_i915_private *dev_priv = ggtt->vm.i915; |
256 | struct intel_uncore *uncore = &dev_priv->uncore; |
257 | unsigned long ggtt_end = ggtt->vm.total; |
258 | |
259 | unsigned long mappable_base, mappable_size, mappable_end; |
260 | unsigned long unmappable_base, unmappable_size, unmappable_end; |
261 | int ret; |
262 | |
263 | if (!intel_vgpu_active(dev_priv: ggtt->vm.i915)) |
264 | return 0; |
265 | |
266 | mappable_base = |
267 | intel_uncore_read(uncore, vgtif_reg(avail_rs.mappable_gmadr.base)); |
268 | mappable_size = |
269 | intel_uncore_read(uncore, vgtif_reg(avail_rs.mappable_gmadr.size)); |
270 | unmappable_base = |
271 | intel_uncore_read(uncore, vgtif_reg(avail_rs.nonmappable_gmadr.base)); |
272 | unmappable_size = |
273 | intel_uncore_read(uncore, vgtif_reg(avail_rs.nonmappable_gmadr.size)); |
274 | |
275 | mappable_end = mappable_base + mappable_size; |
276 | unmappable_end = unmappable_base + unmappable_size; |
277 | |
278 | drm_info(&dev_priv->drm, "VGT ballooning configuration:\n" ); |
279 | drm_info(&dev_priv->drm, |
280 | "Mappable graphic memory: base 0x%lx size %ldKiB\n" , |
281 | mappable_base, mappable_size / 1024); |
282 | drm_info(&dev_priv->drm, |
283 | "Unmappable graphic memory: base 0x%lx size %ldKiB\n" , |
284 | unmappable_base, unmappable_size / 1024); |
285 | |
286 | if (mappable_end > ggtt->mappable_end || |
287 | unmappable_base < ggtt->mappable_end || |
288 | unmappable_end > ggtt_end) { |
289 | drm_err(&dev_priv->drm, "Invalid ballooning configuration!\n" ); |
290 | return -EINVAL; |
291 | } |
292 | |
293 | /* Unmappable graphic memory ballooning */ |
294 | if (unmappable_base > ggtt->mappable_end) { |
295 | ret = vgt_balloon_space(ggtt, node: &bl_info.space[2], |
296 | start: ggtt->mappable_end, end: unmappable_base); |
297 | |
298 | if (ret) |
299 | goto err; |
300 | } |
301 | |
302 | if (unmappable_end < ggtt_end) { |
303 | ret = vgt_balloon_space(ggtt, node: &bl_info.space[3], |
304 | start: unmappable_end, end: ggtt_end); |
305 | if (ret) |
306 | goto err_upon_mappable; |
307 | } |
308 | |
309 | /* Mappable graphic memory ballooning */ |
310 | if (mappable_base) { |
311 | ret = vgt_balloon_space(ggtt, node: &bl_info.space[0], |
312 | start: 0, end: mappable_base); |
313 | |
314 | if (ret) |
315 | goto err_upon_unmappable; |
316 | } |
317 | |
318 | if (mappable_end < ggtt->mappable_end) { |
319 | ret = vgt_balloon_space(ggtt, node: &bl_info.space[1], |
320 | start: mappable_end, end: ggtt->mappable_end); |
321 | |
322 | if (ret) |
323 | goto err_below_mappable; |
324 | } |
325 | |
326 | drm_info(&dev_priv->drm, "VGT balloon successfully\n" ); |
327 | return 0; |
328 | |
329 | err_below_mappable: |
330 | vgt_deballoon_space(ggtt, node: &bl_info.space[0]); |
331 | err_upon_unmappable: |
332 | vgt_deballoon_space(ggtt, node: &bl_info.space[3]); |
333 | err_upon_mappable: |
334 | vgt_deballoon_space(ggtt, node: &bl_info.space[2]); |
335 | err: |
336 | drm_err(&dev_priv->drm, "VGT balloon fail\n" ); |
337 | return ret; |
338 | } |
339 | |