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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_vgpu.h"
25 : :
26 : : /**
27 : : * DOC: Intel GVT-g guest support
28 : : *
29 : : * Intel GVT-g is a graphics virtualization technology which shares the
30 : : * GPU among multiple virtual machines on a time-sharing basis. Each
31 : : * virtual machine is presented a virtual GPU (vGPU), which has equivalent
32 : : * features as the underlying physical GPU (pGPU), so i915 driver can run
33 : : * seamlessly in a virtual machine. This file provides vGPU specific
34 : : * optimizations when running in a virtual machine, to reduce the complexity
35 : : * of vGPU emulation and to improve the overall performance.
36 : : *
37 : : * A primary function introduced here is so-called "address space ballooning"
38 : : * technique. Intel GVT-g partitions global graphics memory among multiple VMs,
39 : : * so each VM can directly access a portion of the memory without hypervisor's
40 : : * intervention, e.g. filling textures or queuing commands. However with the
41 : : * partitioning an unmodified i915 driver would assume a smaller graphics
42 : : * memory starting from address ZERO, then requires vGPU emulation module to
43 : : * translate the graphics address between 'guest view' and 'host view', for
44 : : * all registers and command opcodes which contain a graphics memory address.
45 : : * To reduce the complexity, Intel GVT-g introduces "address space ballooning",
46 : : * by telling the exact partitioning knowledge to each guest i915 driver, which
47 : : * then reserves and prevents non-allocated portions from allocation. Thus vGPU
48 : : * emulation module only needs to scan and validate graphics addresses without
49 : : * complexity of address translation.
50 : : *
51 : : */
52 : :
53 : : /**
54 : : * i915_detect_vgpu - detect virtual GPU
55 : : * @dev_priv: i915 device private
56 : : *
57 : : * This function is called at the initialization stage, to detect whether
58 : : * running on a vGPU.
59 : : */
60 : 0 : void i915_detect_vgpu(struct drm_i915_private *dev_priv)
61 : : {
62 : 0 : struct pci_dev *pdev = dev_priv->drm.pdev;
63 : 0 : u64 magic;
64 : 0 : u16 version_major;
65 : 0 : void __iomem *shared_area;
66 : :
67 : 0 : BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE);
68 : :
69 : : /*
70 : : * This is called before we setup the main MMIO BAR mappings used via
71 : : * the uncore structure, so we need to access the BAR directly. Since
72 : : * we do not support VGT on older gens, return early so we don't have
73 : : * to consider differently numbered or sized MMIO bars
74 : : */
75 [ # # ]: 0 : if (INTEL_GEN(dev_priv) < 6)
76 : : return;
77 : :
78 : 0 : shared_area = pci_iomap_range(pdev, 0, VGT_PVINFO_PAGE, VGT_PVINFO_SIZE);
79 [ # # ]: 0 : if (!shared_area) {
80 : 0 : DRM_ERROR("failed to map MMIO bar to check for VGT\n");
81 : 0 : return;
82 : : }
83 : :
84 : 0 : magic = readq(shared_area + vgtif_offset(magic));
85 [ # # ]: 0 : if (magic != VGT_MAGIC)
86 : 0 : goto out;
87 : :
88 : 0 : version_major = readw(shared_area + vgtif_offset(version_major));
89 [ # # ]: 0 : if (version_major < VGT_VERSION_MAJOR) {
90 : 0 : DRM_INFO("VGT interface version mismatch!\n");
91 : 0 : goto out;
92 : : }
93 : :
94 : 0 : dev_priv->vgpu.caps = readl(shared_area + vgtif_offset(vgt_caps));
95 : :
96 : 0 : dev_priv->vgpu.active = true;
97 : 0 : mutex_init(&dev_priv->vgpu.lock);
98 : 0 : DRM_INFO("Virtual GPU for Intel GVT-g detected.\n");
99 : :
100 : 0 : out:
101 : 0 : pci_iounmap(pdev, shared_area);
102 : : }
103 : :
104 : 0 : bool intel_vgpu_has_full_ppgtt(struct drm_i915_private *dev_priv)
105 : : {
106 : 0 : return dev_priv->vgpu.caps & VGT_CAPS_FULL_PPGTT;
107 : : }
108 : :
109 : : struct _balloon_info_ {
110 : : /*
111 : : * There are up to 2 regions per mappable/unmappable graphic
112 : : * memory that might be ballooned. Here, index 0/1 is for mappable
113 : : * graphic memory, 2/3 for unmappable graphic memory.
114 : : */
115 : : struct drm_mm_node space[4];
116 : : };
117 : :
118 : : static struct _balloon_info_ bl_info;
119 : :
120 : : static void vgt_deballoon_space(struct i915_ggtt *ggtt,
121 : : struct drm_mm_node *node)
122 : : {
123 : : if (!drm_mm_node_allocated(node))
124 : : return;
125 : :
126 : : DRM_DEBUG_DRIVER("deballoon space: range [0x%llx - 0x%llx] %llu KiB.\n",
127 : : node->start,
128 : : node->start + node->size,
129 : : node->size / 1024);
130 : :
131 : : ggtt->vm.reserved -= node->size;
132 : : drm_mm_remove_node(node);
133 : : }
134 : :
135 : : /**
136 : : * intel_vgt_deballoon - deballoon reserved graphics address trunks
137 : : * @ggtt: the global GGTT from which we reserved earlier
138 : : *
139 : : * This function is called to deallocate the ballooned-out graphic memory, when
140 : : * driver is unloaded or when ballooning fails.
141 : : */
142 : 0 : void intel_vgt_deballoon(struct i915_ggtt *ggtt)
143 : : {
144 : 0 : int i;
145 : :
146 [ # # ]: 0 : if (!intel_vgpu_active(ggtt->vm.i915))
147 : : return;
148 : :
149 : 0 : DRM_DEBUG("VGT deballoon.\n");
150 : :
151 [ # # ]: 0 : for (i = 0; i < 4; i++)
152 : 0 : vgt_deballoon_space(ggtt, &bl_info.space[i]);
153 : : }
154 : :
155 : 0 : static int vgt_balloon_space(struct i915_ggtt *ggtt,
156 : : struct drm_mm_node *node,
157 : : unsigned long start, unsigned long end)
158 : : {
159 : 0 : unsigned long size = end - start;
160 : 0 : int ret;
161 : :
162 [ # # ]: 0 : if (start >= end)
163 : : return -EINVAL;
164 : :
165 : 0 : DRM_INFO("balloon space: range [ 0x%lx - 0x%lx ] %lu KiB.\n",
166 : : start, end, size / 1024);
167 : 0 : ret = i915_gem_gtt_reserve(&ggtt->vm, node,
168 : : size, start, I915_COLOR_UNEVICTABLE,
169 : : 0);
170 [ # # ]: 0 : if (!ret)
171 : 0 : ggtt->vm.reserved += size;
172 : :
173 : : return ret;
174 : : }
175 : :
176 : : /**
177 : : * intel_vgt_balloon - balloon out reserved graphics address trunks
178 : : * @ggtt: the global GGTT from which to reserve
179 : : *
180 : : * This function is called at the initialization stage, to balloon out the
181 : : * graphic address space allocated to other vGPUs, by marking these spaces as
182 : : * reserved. The ballooning related knowledge(starting address and size of
183 : : * the mappable/unmappable graphic memory) is described in the vgt_if structure
184 : : * in a reserved mmio range.
185 : : *
186 : : * To give an example, the drawing below depicts one typical scenario after
187 : : * ballooning. Here the vGPU1 has 2 pieces of graphic address spaces ballooned
188 : : * out each for the mappable and the non-mappable part. From the vGPU1 point of
189 : : * view, the total size is the same as the physical one, with the start address
190 : : * of its graphic space being zero. Yet there are some portions ballooned out(
191 : : * the shadow part, which are marked as reserved by drm allocator). From the
192 : : * host point of view, the graphic address space is partitioned by multiple
193 : : * vGPUs in different VMs. ::
194 : : *
195 : : * vGPU1 view Host view
196 : : * 0 ------> +-----------+ +-----------+
197 : : * ^ |###########| | vGPU3 |
198 : : * | |###########| +-----------+
199 : : * | |###########| | vGPU2 |
200 : : * | +-----------+ +-----------+
201 : : * mappable GM | available | ==> | vGPU1 |
202 : : * | +-----------+ +-----------+
203 : : * | |###########| | |
204 : : * v |###########| | Host |
205 : : * +=======+===========+ +===========+
206 : : * ^ |###########| | vGPU3 |
207 : : * | |###########| +-----------+
208 : : * | |###########| | vGPU2 |
209 : : * | +-----------+ +-----------+
210 : : * unmappable GM | available | ==> | vGPU1 |
211 : : * | +-----------+ +-----------+
212 : : * | |###########| | |
213 : : * | |###########| | Host |
214 : : * v |###########| | |
215 : : * total GM size ------> +-----------+ +-----------+
216 : : *
217 : : * Returns:
218 : : * zero on success, non-zero if configuration invalid or ballooning failed
219 : : */
220 : 0 : int intel_vgt_balloon(struct i915_ggtt *ggtt)
221 : : {
222 : 0 : struct intel_uncore *uncore = &ggtt->vm.i915->uncore;
223 : 0 : unsigned long ggtt_end = ggtt->vm.total;
224 : :
225 : 0 : unsigned long mappable_base, mappable_size, mappable_end;
226 : 0 : unsigned long unmappable_base, unmappable_size, unmappable_end;
227 : 0 : int ret;
228 : :
229 [ # # ]: 0 : if (!intel_vgpu_active(ggtt->vm.i915))
230 : : return 0;
231 : :
232 : 0 : mappable_base =
233 : 0 : intel_uncore_read(uncore, vgtif_reg(avail_rs.mappable_gmadr.base));
234 : 0 : mappable_size =
235 : 0 : intel_uncore_read(uncore, vgtif_reg(avail_rs.mappable_gmadr.size));
236 : 0 : unmappable_base =
237 : 0 : intel_uncore_read(uncore, vgtif_reg(avail_rs.nonmappable_gmadr.base));
238 : 0 : unmappable_size =
239 : 0 : intel_uncore_read(uncore, vgtif_reg(avail_rs.nonmappable_gmadr.size));
240 : :
241 : 0 : mappable_end = mappable_base + mappable_size;
242 : 0 : unmappable_end = unmappable_base + unmappable_size;
243 : :
244 : 0 : DRM_INFO("VGT ballooning configuration:\n");
245 : 0 : DRM_INFO("Mappable graphic memory: base 0x%lx size %ldKiB\n",
246 : : mappable_base, mappable_size / 1024);
247 : 0 : DRM_INFO("Unmappable graphic memory: base 0x%lx size %ldKiB\n",
248 : : unmappable_base, unmappable_size / 1024);
249 : :
250 [ # # # # ]: 0 : if (mappable_end > ggtt->mappable_end ||
251 [ # # ]: 0 : unmappable_base < ggtt->mappable_end ||
252 : : unmappable_end > ggtt_end) {
253 : 0 : DRM_ERROR("Invalid ballooning configuration!\n");
254 : 0 : return -EINVAL;
255 : : }
256 : :
257 : : /* Unmappable graphic memory ballooning */
258 [ # # ]: 0 : if (unmappable_base > ggtt->mappable_end) {
259 : 0 : ret = vgt_balloon_space(ggtt, &bl_info.space[2],
260 : : ggtt->mappable_end, unmappable_base);
261 : :
262 [ # # ]: 0 : if (ret)
263 : 0 : goto err;
264 : : }
265 : :
266 [ # # ]: 0 : if (unmappable_end < ggtt_end) {
267 : 0 : ret = vgt_balloon_space(ggtt, &bl_info.space[3],
268 : : unmappable_end, ggtt_end);
269 [ # # ]: 0 : if (ret)
270 : 0 : goto err_upon_mappable;
271 : : }
272 : :
273 : : /* Mappable graphic memory ballooning */
274 [ # # ]: 0 : if (mappable_base) {
275 : 0 : ret = vgt_balloon_space(ggtt, &bl_info.space[0],
276 : : 0, mappable_base);
277 : :
278 [ # # ]: 0 : if (ret)
279 : 0 : goto err_upon_unmappable;
280 : : }
281 : :
282 [ # # ]: 0 : if (mappable_end < ggtt->mappable_end) {
283 : 0 : ret = vgt_balloon_space(ggtt, &bl_info.space[1],
284 : : mappable_end, ggtt->mappable_end);
285 : :
286 [ # # ]: 0 : if (ret)
287 : 0 : goto err_below_mappable;
288 : : }
289 : :
290 : 0 : DRM_INFO("VGT balloon successfully\n");
291 : 0 : return 0;
292 : :
293 : : err_below_mappable:
294 : 0 : vgt_deballoon_space(ggtt, &bl_info.space[0]);
295 : 0 : err_upon_unmappable:
296 : 0 : vgt_deballoon_space(ggtt, &bl_info.space[3]);
297 : 0 : err_upon_mappable:
298 : 0 : vgt_deballoon_space(ggtt, &bl_info.space[2]);
299 : 0 : err:
300 : 0 : DRM_ERROR("VGT balloon fail\n");
301 : 0 : return ret;
302 : : }
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