/* * Copyright(c) 2011-2015 Intel Corporation. All rights reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include "i915_drv.h" #include "i915_pvinfo.h" #include "i915_vgpu.h" /** * DOC: Intel GVT-g guest support * * Intel GVT-g is a graphics virtualization technology which shares the * GPU among multiple virtual machines on a time-sharing basis. Each * virtual machine is presented a virtual GPU (vGPU), which has equivalent * features as the underlying physical GPU (pGPU), so i915 driver can run * seamlessly in a virtual machine. This file provides vGPU specific * optimizations when running in a virtual machine, to reduce the complexity * of vGPU emulation and to improve the overall performance. * * A primary function introduced here is so-called "address space ballooning" * technique. Intel GVT-g partitions global graphics memory among multiple VMs, * so each VM can directly access a portion of the memory without hypervisor's * intervention, e.g. filling textures or queuing commands. However with the * partitioning an unmodified i915 driver would assume a smaller graphics * memory starting from address ZERO, then requires vGPU emulation module to * translate the graphics address between 'guest view' and 'host view', for * all registers and command opcodes which contain a graphics memory address. * To reduce the complexity, Intel GVT-g introduces "address space ballooning", * by telling the exact partitioning knowledge to each guest i915 driver, which * then reserves and prevents non-allocated portions from allocation. Thus vGPU * emulation module only needs to scan and validate graphics addresses without * complexity of address translation. * */ /** * intel_vgpu_detect - detect virtual GPU * @dev_priv: i915 device private * * This function is called at the initialization stage, to detect whether * running on a vGPU. */ void intel_vgpu_detect(struct drm_i915_private *dev_priv) { … } void intel_vgpu_register(struct drm_i915_private *i915) { … } bool intel_vgpu_active(struct drm_i915_private *dev_priv) { … } bool intel_vgpu_has_full_ppgtt(struct drm_i915_private *dev_priv) { … } bool intel_vgpu_has_hwsp_emulation(struct drm_i915_private *dev_priv) { … } bool intel_vgpu_has_huge_gtt(struct drm_i915_private *dev_priv) { … } struct _balloon_info_ { … }; static struct _balloon_info_ bl_info; static void vgt_deballoon_space(struct i915_ggtt *ggtt, struct drm_mm_node *node) { … } /** * intel_vgt_deballoon - deballoon reserved graphics address trunks * @ggtt: the global GGTT from which we reserved earlier * * This function is called to deallocate the ballooned-out graphic memory, when * driver is unloaded or when ballooning fails. */ void intel_vgt_deballoon(struct i915_ggtt *ggtt) { … } static int vgt_balloon_space(struct i915_ggtt *ggtt, struct drm_mm_node *node, unsigned long start, unsigned long end) { … } /** * intel_vgt_balloon - balloon out reserved graphics address trunks * @ggtt: the global GGTT from which to reserve * * This function is called at the initialization stage, to balloon out the * graphic address space allocated to other vGPUs, by marking these spaces as * reserved. The ballooning related knowledge(starting address and size of * the mappable/unmappable graphic memory) is described in the vgt_if structure * in a reserved mmio range. * * To give an example, the drawing below depicts one typical scenario after * ballooning. Here the vGPU1 has 2 pieces of graphic address spaces ballooned * out each for the mappable and the non-mappable part. From the vGPU1 point of * view, the total size is the same as the physical one, with the start address * of its graphic space being zero. Yet there are some portions ballooned out( * the shadow part, which are marked as reserved by drm allocator). From the * host point of view, the graphic address space is partitioned by multiple * vGPUs in different VMs. :: * * vGPU1 view Host view * 0 ------> +-----------+ +-----------+ * ^ |###########| | vGPU3 | * | |###########| +-----------+ * | |###########| | vGPU2 | * | +-----------+ +-----------+ * mappable GM | available | ==> | vGPU1 | * | +-----------+ +-----------+ * | |###########| | | * v |###########| | Host | * +=======+===========+ +===========+ * ^ |###########| | vGPU3 | * | |###########| +-----------+ * | |###########| | vGPU2 | * | +-----------+ +-----------+ * unmappable GM | available | ==> | vGPU1 | * | +-----------+ +-----------+ * | |###########| | | * | |###########| | Host | * v |###########| | | * total GM size ------> +-----------+ +-----------+ * * Returns: * zero on success, non-zero if configuration invalid or ballooning failed */ int intel_vgt_balloon(struct i915_ggtt *ggtt) { … }
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