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![Xiaolin Zhang](/assets/img/avatar_default.png)
vgpu ppgtt notification was split into 2 steps, the first step is to update PVINFO's pdp register and then write PVINFO's g2v_notify register with action code to tirgger ppgtt notification to GVT side. currently these steps were not atomic operations due to no any protection, so it is easy to enter race condition state during the MTBF, stress and IGT test to cause GPU hang. the solution is to add a lock to make vgpu ppgtt notication as atomic operation. Cc: stable@vger.kernel.org Signed-off-by: Xiaolin Zhang <xiaolin.zhang@intel.com> Acked-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Link: https://patchwork.freedesktop.org/patch/msgid/1566543451-13955-1-git-send-email-xiaolin.zhang@intel.com
302 lines
10 KiB
C
302 lines
10 KiB
C
/*
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* Copyright(c) 2011-2015 Intel Corporation. All rights reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the next
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* paragraph) shall be included in all copies or substantial portions of the
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* Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include "i915_vgpu.h"
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/**
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* DOC: Intel GVT-g guest support
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*
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* Intel GVT-g is a graphics virtualization technology which shares the
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* GPU among multiple virtual machines on a time-sharing basis. Each
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* virtual machine is presented a virtual GPU (vGPU), which has equivalent
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* features as the underlying physical GPU (pGPU), so i915 driver can run
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* seamlessly in a virtual machine. This file provides vGPU specific
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* optimizations when running in a virtual machine, to reduce the complexity
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* of vGPU emulation and to improve the overall performance.
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*
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* A primary function introduced here is so-called "address space ballooning"
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* technique. Intel GVT-g partitions global graphics memory among multiple VMs,
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* so each VM can directly access a portion of the memory without hypervisor's
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* intervention, e.g. filling textures or queuing commands. However with the
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* partitioning an unmodified i915 driver would assume a smaller graphics
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* memory starting from address ZERO, then requires vGPU emulation module to
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* translate the graphics address between 'guest view' and 'host view', for
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* all registers and command opcodes which contain a graphics memory address.
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* To reduce the complexity, Intel GVT-g introduces "address space ballooning",
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* by telling the exact partitioning knowledge to each guest i915 driver, which
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* then reserves and prevents non-allocated portions from allocation. Thus vGPU
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* emulation module only needs to scan and validate graphics addresses without
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* complexity of address translation.
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*
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*/
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/**
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* i915_detect_vgpu - detect virtual GPU
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* @dev_priv: i915 device private
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*
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* This function is called at the initialization stage, to detect whether
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* running on a vGPU.
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*/
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void i915_detect_vgpu(struct drm_i915_private *dev_priv)
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{
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struct pci_dev *pdev = dev_priv->drm.pdev;
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u64 magic;
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u16 version_major;
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void __iomem *shared_area;
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BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE);
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/*
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* This is called before we setup the main MMIO BAR mappings used via
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* the uncore structure, so we need to access the BAR directly. Since
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* we do not support VGT on older gens, return early so we don't have
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* to consider differently numbered or sized MMIO bars
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*/
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if (INTEL_GEN(dev_priv) < 6)
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return;
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shared_area = pci_iomap_range(pdev, 0, VGT_PVINFO_PAGE, VGT_PVINFO_SIZE);
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if (!shared_area) {
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DRM_ERROR("failed to map MMIO bar to check for VGT\n");
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return;
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}
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magic = readq(shared_area + vgtif_offset(magic));
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if (magic != VGT_MAGIC)
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goto out;
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version_major = readw(shared_area + vgtif_offset(version_major));
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if (version_major < VGT_VERSION_MAJOR) {
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DRM_INFO("VGT interface version mismatch!\n");
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goto out;
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}
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dev_priv->vgpu.caps = readl(shared_area + vgtif_offset(vgt_caps));
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dev_priv->vgpu.active = true;
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mutex_init(&dev_priv->vgpu.lock);
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DRM_INFO("Virtual GPU for Intel GVT-g detected.\n");
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out:
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pci_iounmap(pdev, shared_area);
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}
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bool intel_vgpu_has_full_ppgtt(struct drm_i915_private *dev_priv)
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{
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return dev_priv->vgpu.caps & VGT_CAPS_FULL_PPGTT;
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}
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struct _balloon_info_ {
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/*
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* There are up to 2 regions per mappable/unmappable graphic
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* memory that might be ballooned. Here, index 0/1 is for mappable
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* graphic memory, 2/3 for unmappable graphic memory.
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*/
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struct drm_mm_node space[4];
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};
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static struct _balloon_info_ bl_info;
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static void vgt_deballoon_space(struct i915_ggtt *ggtt,
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struct drm_mm_node *node)
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{
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if (!drm_mm_node_allocated(node))
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return;
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DRM_DEBUG_DRIVER("deballoon space: range [0x%llx - 0x%llx] %llu KiB.\n",
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node->start,
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node->start + node->size,
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node->size / 1024);
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ggtt->vm.reserved -= node->size;
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drm_mm_remove_node(node);
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}
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/**
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* intel_vgt_deballoon - deballoon reserved graphics address trunks
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* @ggtt: the global GGTT from which we reserved earlier
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*
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* This function is called to deallocate the ballooned-out graphic memory, when
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* driver is unloaded or when ballooning fails.
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*/
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void intel_vgt_deballoon(struct i915_ggtt *ggtt)
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{
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int i;
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if (!intel_vgpu_active(ggtt->vm.i915))
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return;
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DRM_DEBUG("VGT deballoon.\n");
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for (i = 0; i < 4; i++)
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vgt_deballoon_space(ggtt, &bl_info.space[i]);
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}
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static int vgt_balloon_space(struct i915_ggtt *ggtt,
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struct drm_mm_node *node,
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unsigned long start, unsigned long end)
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{
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unsigned long size = end - start;
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int ret;
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if (start >= end)
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return -EINVAL;
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DRM_INFO("balloon space: range [ 0x%lx - 0x%lx ] %lu KiB.\n",
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start, end, size / 1024);
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ret = i915_gem_gtt_reserve(&ggtt->vm, node,
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size, start, I915_COLOR_UNEVICTABLE,
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0);
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if (!ret)
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ggtt->vm.reserved += size;
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return ret;
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}
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/**
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* intel_vgt_balloon - balloon out reserved graphics address trunks
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* @ggtt: the global GGTT from which to reserve
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*
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* This function is called at the initialization stage, to balloon out the
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* graphic address space allocated to other vGPUs, by marking these spaces as
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* reserved. The ballooning related knowledge(starting address and size of
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* the mappable/unmappable graphic memory) is described in the vgt_if structure
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* in a reserved mmio range.
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*
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* To give an example, the drawing below depicts one typical scenario after
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* ballooning. Here the vGPU1 has 2 pieces of graphic address spaces ballooned
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* out each for the mappable and the non-mappable part. From the vGPU1 point of
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* view, the total size is the same as the physical one, with the start address
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* of its graphic space being zero. Yet there are some portions ballooned out(
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* the shadow part, which are marked as reserved by drm allocator). From the
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* host point of view, the graphic address space is partitioned by multiple
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* vGPUs in different VMs. ::
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*
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* vGPU1 view Host view
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* 0 ------> +-----------+ +-----------+
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* ^ |###########| | vGPU3 |
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* | |###########| +-----------+
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* | |###########| | vGPU2 |
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* | +-----------+ +-----------+
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* mappable GM | available | ==> | vGPU1 |
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* | +-----------+ +-----------+
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* | |###########| | |
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* v |###########| | Host |
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* +=======+===========+ +===========+
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* ^ |###########| | vGPU3 |
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* | |###########| +-----------+
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* | |###########| | vGPU2 |
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* | +-----------+ +-----------+
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* unmappable GM | available | ==> | vGPU1 |
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* | +-----------+ +-----------+
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* | |###########| | |
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* | |###########| | Host |
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* v |###########| | |
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* total GM size ------> +-----------+ +-----------+
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*
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* Returns:
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* zero on success, non-zero if configuration invalid or ballooning failed
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*/
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int intel_vgt_balloon(struct i915_ggtt *ggtt)
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{
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struct intel_uncore *uncore = &ggtt->vm.i915->uncore;
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unsigned long ggtt_end = ggtt->vm.total;
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unsigned long mappable_base, mappable_size, mappable_end;
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unsigned long unmappable_base, unmappable_size, unmappable_end;
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int ret;
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if (!intel_vgpu_active(ggtt->vm.i915))
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return 0;
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mappable_base =
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intel_uncore_read(uncore, vgtif_reg(avail_rs.mappable_gmadr.base));
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mappable_size =
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intel_uncore_read(uncore, vgtif_reg(avail_rs.mappable_gmadr.size));
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unmappable_base =
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intel_uncore_read(uncore, vgtif_reg(avail_rs.nonmappable_gmadr.base));
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unmappable_size =
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intel_uncore_read(uncore, vgtif_reg(avail_rs.nonmappable_gmadr.size));
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mappable_end = mappable_base + mappable_size;
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unmappable_end = unmappable_base + unmappable_size;
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DRM_INFO("VGT ballooning configuration:\n");
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DRM_INFO("Mappable graphic memory: base 0x%lx size %ldKiB\n",
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mappable_base, mappable_size / 1024);
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DRM_INFO("Unmappable graphic memory: base 0x%lx size %ldKiB\n",
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unmappable_base, unmappable_size / 1024);
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if (mappable_end > ggtt->mappable_end ||
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unmappable_base < ggtt->mappable_end ||
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unmappable_end > ggtt_end) {
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DRM_ERROR("Invalid ballooning configuration!\n");
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return -EINVAL;
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}
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/* Unmappable graphic memory ballooning */
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if (unmappable_base > ggtt->mappable_end) {
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ret = vgt_balloon_space(ggtt, &bl_info.space[2],
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ggtt->mappable_end, unmappable_base);
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if (ret)
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goto err;
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}
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if (unmappable_end < ggtt_end) {
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ret = vgt_balloon_space(ggtt, &bl_info.space[3],
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unmappable_end, ggtt_end);
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if (ret)
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goto err_upon_mappable;
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}
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/* Mappable graphic memory ballooning */
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if (mappable_base) {
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ret = vgt_balloon_space(ggtt, &bl_info.space[0],
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0, mappable_base);
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if (ret)
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goto err_upon_unmappable;
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}
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if (mappable_end < ggtt->mappable_end) {
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ret = vgt_balloon_space(ggtt, &bl_info.space[1],
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mappable_end, ggtt->mappable_end);
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if (ret)
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goto err_below_mappable;
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}
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DRM_INFO("VGT balloon successfully\n");
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return 0;
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err_below_mappable:
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vgt_deballoon_space(ggtt, &bl_info.space[0]);
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err_upon_unmappable:
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vgt_deballoon_space(ggtt, &bl_info.space[3]);
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err_upon_mappable:
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vgt_deballoon_space(ggtt, &bl_info.space[2]);
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err:
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DRM_ERROR("VGT balloon fail\n");
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return ret;
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}
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