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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 "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
56 * @dev: drm device *
57 *
58 * This function is called at the initialization stage, to detect whether
59 * running on a vGPU.
60 */
61void i915_check_vgpu(struct drm_device *dev)
62{
63 struct drm_i915_private *dev_priv = to_i915(dev);
64 uint64_t magic;
65 uint32_t version;
66
67 BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE);
68
69 if (!IS_HASWELL(dev))
70 return;
71
72 magic = __raw_i915_read64(dev_priv, vgtif_reg(magic));
73 if (magic != VGT_MAGIC)
74 return;
75
76 version = INTEL_VGT_IF_VERSION_ENCODE(
77 __raw_i915_read16(dev_priv, vgtif_reg(version_major)),
78 __raw_i915_read16(dev_priv, vgtif_reg(version_minor)));
79 if (version != INTEL_VGT_IF_VERSION) {
80 DRM_INFO("VGT interface version mismatch!\n");
81 return;
82 }
83
84 dev_priv->vgpu.active = true;
85 DRM_INFO("Virtual GPU for Intel GVT-g detected.\n");
86}
87
88struct _balloon_info_ {
89 /*
90 * There are up to 2 regions per mappable/unmappable graphic
91 * memory that might be ballooned. Here, index 0/1 is for mappable
92 * graphic memory, 2/3 for unmappable graphic memory.
93 */
94 struct drm_mm_node space[4];
95};
96
97static struct _balloon_info_ bl_info;
98
99/**
100 * intel_vgt_deballoon - deballoon reserved graphics address trunks
101 *
102 * This function is called to deallocate the ballooned-out graphic memory, when
103 * driver is unloaded or when ballooning fails.
104 */
105void intel_vgt_deballoon(void)
106{
107 int i;
108
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
119static 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
139 * @dev: drm device
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
154 * vGPUs in different VMs.
155 *
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 ------> +-----------+ +-----------+
177 *
178 * Returns:
179 * zero on success, non-zero if configuration invalid or ballooning failed
180 */
181int intel_vgt_balloon(struct drm_device *dev)
182{
183 struct drm_i915_private *dev_priv = to_i915(dev);
184 struct i915_address_space *ggtt_vm = &dev_priv->gtt.base;
185 unsigned long ggtt_vm_end = ggtt_vm->start + ggtt_vm->total;
186
187 unsigned long mappable_base, mappable_size, mappable_end;
188 unsigned long unmappable_base, unmappable_size, unmappable_end;
189 int ret;
190
191 mappable_base = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.base));
192 mappable_size = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.size));
193 unmappable_base = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.base));
194 unmappable_size = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.size));
195
196 mappable_end = mappable_base + mappable_size;
197 unmappable_end = unmappable_base + unmappable_size;
198
199 DRM_INFO("VGT ballooning configuration:\n");
200 DRM_INFO("Mappable graphic memory: base 0x%lx size %ldKiB\n",
201 mappable_base, mappable_size / 1024);
202 DRM_INFO("Unmappable graphic memory: base 0x%lx size %ldKiB\n",
203 unmappable_base, unmappable_size / 1024);
204
205 if (mappable_base < ggtt_vm->start ||
206 mappable_end > dev_priv->gtt.mappable_end ||
207 unmappable_base < dev_priv->gtt.mappable_end ||
208 unmappable_end > ggtt_vm_end) {
209 DRM_ERROR("Invalid ballooning configuration!\n");
210 return -EINVAL;
211 }
212
213 /* Unmappable graphic memory ballooning */
214 if (unmappable_base > dev_priv->gtt.mappable_end) {
215 ret = vgt_balloon_space(&ggtt_vm->mm,
216 &bl_info.space[2],
217 dev_priv->gtt.mappable_end,
218 unmappable_base);
219
220 if (ret)
221 goto err;
222 }
223
224 /*
225 * No need to partition out the last physical page,
226 * because it is reserved to the guard page.
227 */
228 if (unmappable_end < ggtt_vm_end - PAGE_SIZE) {
229 ret = vgt_balloon_space(&ggtt_vm->mm,
230 &bl_info.space[3],
231 unmappable_end,
232 ggtt_vm_end - PAGE_SIZE);
233 if (ret)
234 goto err;
235 }
236
237 /* Mappable graphic memory ballooning */
238 if (mappable_base > ggtt_vm->start) {
239 ret = vgt_balloon_space(&ggtt_vm->mm,
240 &bl_info.space[0],
241 ggtt_vm->start, mappable_base);
242
243 if (ret)
244 goto err;
245 }
246
247 if (mappable_end < dev_priv->gtt.mappable_end) {
248 ret = vgt_balloon_space(&ggtt_vm->mm,
249 &bl_info.space[1],
250 mappable_end,
251 dev_priv->gtt.mappable_end);
252
253 if (ret)
254 goto err;
255 }
256
257 DRM_INFO("VGT balloon successfully\n");
258 return 0;
259
260err:
261 DRM_ERROR("VGT balloon fail\n");
262 intel_vgt_deballoon();
263 return ret;
264}
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
56 * @dev_priv: i915 device private
57 *
58 * This function is called at the initialization stage, to detect whether
59 * running on a vGPU.
60 */
61void i915_check_vgpu(struct drm_i915_private *dev_priv)
62{
63 u64 magic;
64 u16 version_major;
65
66 BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE);
67
68 magic = __raw_i915_read64(dev_priv, vgtif_reg(magic));
69 if (magic != VGT_MAGIC)
70 return;
71
72 version_major = __raw_i915_read16(dev_priv, vgtif_reg(version_major));
73 if (version_major < VGT_VERSION_MAJOR) {
74 DRM_INFO("VGT interface version mismatch!\n");
75 return;
76 }
77
78 dev_priv->vgpu.caps = __raw_i915_read32(dev_priv, vgtif_reg(vgt_caps));
79
80 dev_priv->vgpu.active = true;
81 DRM_INFO("Virtual GPU for Intel GVT-g detected.\n");
82}
83
84bool intel_vgpu_has_full_48bit_ppgtt(struct drm_i915_private *dev_priv)
85{
86 return dev_priv->vgpu.caps & VGT_CAPS_FULL_48BIT_PPGTT;
87}
88
89struct _balloon_info_ {
90 /*
91 * There are up to 2 regions per mappable/unmappable graphic
92 * memory that might be ballooned. Here, index 0/1 is for mappable
93 * graphic memory, 2/3 for unmappable graphic memory.
94 */
95 struct drm_mm_node space[4];
96};
97
98static struct _balloon_info_ bl_info;
99
100static void vgt_deballoon_space(struct i915_ggtt *ggtt,
101 struct drm_mm_node *node)
102{
103 DRM_DEBUG_DRIVER("deballoon space: range [0x%llx - 0x%llx] %llu KiB.\n",
104 node->start,
105 node->start + node->size,
106 node->size / 1024);
107
108 ggtt->base.reserved -= node->size;
109 drm_mm_remove_node(node);
110}
111
112/**
113 * intel_vgt_deballoon - deballoon reserved graphics address trunks
114 * @dev_priv: i915 device private data
115 *
116 * This function is called to deallocate the ballooned-out graphic memory, when
117 * driver is unloaded or when ballooning fails.
118 */
119void intel_vgt_deballoon(struct drm_i915_private *dev_priv)
120{
121 int i;
122
123 if (!intel_vgpu_active(dev_priv))
124 return;
125
126 DRM_DEBUG("VGT deballoon.\n");
127
128 for (i = 0; i < 4; i++)
129 vgt_deballoon_space(&dev_priv->ggtt, &bl_info.space[i]);
130}
131
132static int vgt_balloon_space(struct i915_ggtt *ggtt,
133 struct drm_mm_node *node,
134 unsigned long start, unsigned long end)
135{
136 unsigned long size = end - start;
137 int ret;
138
139 if (start >= end)
140 return -EINVAL;
141
142 DRM_INFO("balloon space: range [ 0x%lx - 0x%lx ] %lu KiB.\n",
143 start, end, size / 1024);
144 ret = i915_gem_gtt_reserve(&ggtt->base, node,
145 size, start, I915_COLOR_UNEVICTABLE,
146 0);
147 if (!ret)
148 ggtt->base.reserved += size;
149
150 return ret;
151}
152
153/**
154 * intel_vgt_balloon - balloon out reserved graphics address trunks
155 * @dev_priv: i915 device private data
156 *
157 * This function is called at the initialization stage, to balloon out the
158 * graphic address space allocated to other vGPUs, by marking these spaces as
159 * reserved. The ballooning related knowledge(starting address and size of
160 * the mappable/unmappable graphic memory) is described in the vgt_if structure
161 * in a reserved mmio range.
162 *
163 * To give an example, the drawing below depicts one typical scenario after
164 * ballooning. Here the vGPU1 has 2 pieces of graphic address spaces ballooned
165 * out each for the mappable and the non-mappable part. From the vGPU1 point of
166 * view, the total size is the same as the physical one, with the start address
167 * of its graphic space being zero. Yet there are some portions ballooned out(
168 * the shadow part, which are marked as reserved by drm allocator). From the
169 * host point of view, the graphic address space is partitioned by multiple
170 * vGPUs in different VMs. ::
171 *
172 * vGPU1 view Host view
173 * 0 ------> +-----------+ +-----------+
174 * ^ |###########| | vGPU3 |
175 * | |###########| +-----------+
176 * | |###########| | vGPU2 |
177 * | +-----------+ +-----------+
178 * mappable GM | available | ==> | vGPU1 |
179 * | +-----------+ +-----------+
180 * | |###########| | |
181 * v |###########| | Host |
182 * +=======+===========+ +===========+
183 * ^ |###########| | vGPU3 |
184 * | |###########| +-----------+
185 * | |###########| | vGPU2 |
186 * | +-----------+ +-----------+
187 * unmappable GM | available | ==> | vGPU1 |
188 * | +-----------+ +-----------+
189 * | |###########| | |
190 * | |###########| | Host |
191 * v |###########| | |
192 * total GM size ------> +-----------+ +-----------+
193 *
194 * Returns:
195 * zero on success, non-zero if configuration invalid or ballooning failed
196 */
197int intel_vgt_balloon(struct drm_i915_private *dev_priv)
198{
199 struct i915_ggtt *ggtt = &dev_priv->ggtt;
200 unsigned long ggtt_end = ggtt->base.total;
201
202 unsigned long mappable_base, mappable_size, mappable_end;
203 unsigned long unmappable_base, unmappable_size, unmappable_end;
204 int ret;
205
206 if (!intel_vgpu_active(dev_priv))
207 return 0;
208
209 mappable_base = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.base));
210 mappable_size = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.size));
211 unmappable_base = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.base));
212 unmappable_size = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.size));
213
214 mappable_end = mappable_base + mappable_size;
215 unmappable_end = unmappable_base + unmappable_size;
216
217 DRM_INFO("VGT ballooning configuration:\n");
218 DRM_INFO("Mappable graphic memory: base 0x%lx size %ldKiB\n",
219 mappable_base, mappable_size / 1024);
220 DRM_INFO("Unmappable graphic memory: base 0x%lx size %ldKiB\n",
221 unmappable_base, unmappable_size / 1024);
222
223 if (mappable_end > ggtt->mappable_end ||
224 unmappable_base < ggtt->mappable_end ||
225 unmappable_end > ggtt_end) {
226 DRM_ERROR("Invalid ballooning configuration!\n");
227 return -EINVAL;
228 }
229
230 /* Unmappable graphic memory ballooning */
231 if (unmappable_base > ggtt->mappable_end) {
232 ret = vgt_balloon_space(ggtt, &bl_info.space[2],
233 ggtt->mappable_end, unmappable_base);
234
235 if (ret)
236 goto err;
237 }
238
239 if (unmappable_end < ggtt_end) {
240 ret = vgt_balloon_space(ggtt, &bl_info.space[3],
241 unmappable_end, ggtt_end);
242 if (ret)
243 goto err_upon_mappable;
244 }
245
246 /* Mappable graphic memory ballooning */
247 if (mappable_base) {
248 ret = vgt_balloon_space(ggtt, &bl_info.space[0],
249 0, mappable_base);
250
251 if (ret)
252 goto err_upon_unmappable;
253 }
254
255 if (mappable_end < ggtt->mappable_end) {
256 ret = vgt_balloon_space(ggtt, &bl_info.space[1],
257 mappable_end, ggtt->mappable_end);
258
259 if (ret)
260 goto err_below_mappable;
261 }
262
263 DRM_INFO("VGT balloon successfully\n");
264 return 0;
265
266err_below_mappable:
267 vgt_deballoon_space(ggtt, &bl_info.space[0]);
268err_upon_unmappable:
269 vgt_deballoon_space(ggtt, &bl_info.space[3]);
270err_upon_mappable:
271 vgt_deballoon_space(ggtt, &bl_info.space[2]);
272err:
273 DRM_ERROR("VGT balloon fail\n");
274 return ret;
275}