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Diffstat (limited to 'drivers/gpu/drm/i915/i915_vgpu.c')
-rw-r--r--drivers/gpu/drm/i915/i915_vgpu.c338
1 files changed, 338 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_vgpu.c b/drivers/gpu/drm/i915/i915_vgpu.c
new file mode 100644
index 000000000..c97323973
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_vgpu.c
@@ -0,0 +1,338 @@
+/*
+ * 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)
+{
+ struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
+ u64 magic;
+ u16 version_major;
+ void __iomem *shared_area;
+
+ BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE);
+
+ /*
+ * This is called before we setup the main MMIO BAR mappings used via
+ * the uncore structure, so we need to access the BAR directly. Since
+ * we do not support VGT on older gens, return early so we don't have
+ * to consider differently numbered or sized MMIO bars
+ */
+ if (GRAPHICS_VER(dev_priv) < 6)
+ return;
+
+ shared_area = pci_iomap_range(pdev, 0, VGT_PVINFO_PAGE, VGT_PVINFO_SIZE);
+ if (!shared_area) {
+ drm_err(&dev_priv->drm,
+ "failed to map MMIO bar to check for VGT\n");
+ return;
+ }
+
+ magic = readq(shared_area + vgtif_offset(magic));
+ if (magic != VGT_MAGIC)
+ goto out;
+
+ version_major = readw(shared_area + vgtif_offset(version_major));
+ if (version_major < VGT_VERSION_MAJOR) {
+ drm_info(&dev_priv->drm, "VGT interface version mismatch!\n");
+ goto out;
+ }
+
+ dev_priv->vgpu.caps = readl(shared_area + vgtif_offset(vgt_caps));
+
+ dev_priv->vgpu.active = true;
+ mutex_init(&dev_priv->vgpu.lock);
+ drm_info(&dev_priv->drm, "Virtual GPU for Intel GVT-g detected.\n");
+
+out:
+ pci_iounmap(pdev, shared_area);
+}
+
+void intel_vgpu_register(struct drm_i915_private *i915)
+{
+ /*
+ * Notify a valid surface after modesetting, when running inside a VM.
+ */
+ if (intel_vgpu_active(i915))
+ intel_uncore_write(&i915->uncore, vgtif_reg(display_ready),
+ VGT_DRV_DISPLAY_READY);
+}
+
+bool intel_vgpu_active(struct drm_i915_private *dev_priv)
+{
+ return dev_priv->vgpu.active;
+}
+
+bool intel_vgpu_has_full_ppgtt(struct drm_i915_private *dev_priv)
+{
+ return dev_priv->vgpu.caps & VGT_CAPS_FULL_PPGTT;
+}
+
+bool intel_vgpu_has_hwsp_emulation(struct drm_i915_private *dev_priv)
+{
+ return dev_priv->vgpu.caps & VGT_CAPS_HWSP_EMULATION;
+}
+
+bool intel_vgpu_has_huge_gtt(struct drm_i915_private *dev_priv)
+{
+ return dev_priv->vgpu.caps & VGT_CAPS_HUGE_GTT;
+}
+
+struct _balloon_info_ {
+ /*
+ * There are up to 2 regions per mappable/unmappable graphic
+ * memory that might be ballooned. Here, index 0/1 is for mappable
+ * graphic memory, 2/3 for unmappable graphic memory.
+ */
+ struct drm_mm_node space[4];
+};
+
+static struct _balloon_info_ bl_info;
+
+static void vgt_deballoon_space(struct i915_ggtt *ggtt,
+ struct drm_mm_node *node)
+{
+ struct drm_i915_private *dev_priv = ggtt->vm.i915;
+ if (!drm_mm_node_allocated(node))
+ return;
+
+ drm_dbg(&dev_priv->drm,
+ "deballoon space: range [0x%llx - 0x%llx] %llu KiB.\n",
+ node->start,
+ node->start + node->size,
+ node->size / 1024);
+
+ ggtt->vm.reserved -= node->size;
+ drm_mm_remove_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)
+{
+ struct drm_i915_private *dev_priv = ggtt->vm.i915;
+ int i;
+
+ if (!intel_vgpu_active(ggtt->vm.i915))
+ return;
+
+ drm_dbg(&dev_priv->drm, "VGT deballoon.\n");
+
+ for (i = 0; i < 4; i++)
+ vgt_deballoon_space(ggtt, &bl_info.space[i]);
+}
+
+static int vgt_balloon_space(struct i915_ggtt *ggtt,
+ struct drm_mm_node *node,
+ unsigned long start, unsigned long end)
+{
+ struct drm_i915_private *dev_priv = ggtt->vm.i915;
+ unsigned long size = end - start;
+ int ret;
+
+ if (start >= end)
+ return -EINVAL;
+
+ drm_info(&dev_priv->drm,
+ "balloon space: range [ 0x%lx - 0x%lx ] %lu KiB.\n",
+ start, end, size / 1024);
+ ret = i915_gem_gtt_reserve(&ggtt->vm, NULL, node,
+ size, start, I915_COLOR_UNEVICTABLE,
+ 0);
+ if (!ret)
+ ggtt->vm.reserved += size;
+
+ return ret;
+}
+
+/**
+ * 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)
+{
+ struct drm_i915_private *dev_priv = ggtt->vm.i915;
+ struct intel_uncore *uncore = &dev_priv->uncore;
+ unsigned long ggtt_end = ggtt->vm.total;
+
+ unsigned long mappable_base, mappable_size, mappable_end;
+ unsigned long unmappable_base, unmappable_size, unmappable_end;
+ int ret;
+
+ if (!intel_vgpu_active(ggtt->vm.i915))
+ return 0;
+
+ mappable_base =
+ intel_uncore_read(uncore, vgtif_reg(avail_rs.mappable_gmadr.base));
+ mappable_size =
+ intel_uncore_read(uncore, vgtif_reg(avail_rs.mappable_gmadr.size));
+ unmappable_base =
+ intel_uncore_read(uncore, vgtif_reg(avail_rs.nonmappable_gmadr.base));
+ unmappable_size =
+ intel_uncore_read(uncore, vgtif_reg(avail_rs.nonmappable_gmadr.size));
+
+ mappable_end = mappable_base + mappable_size;
+ unmappable_end = unmappable_base + unmappable_size;
+
+ drm_info(&dev_priv->drm, "VGT ballooning configuration:\n");
+ drm_info(&dev_priv->drm,
+ "Mappable graphic memory: base 0x%lx size %ldKiB\n",
+ mappable_base, mappable_size / 1024);
+ drm_info(&dev_priv->drm,
+ "Unmappable graphic memory: base 0x%lx size %ldKiB\n",
+ unmappable_base, unmappable_size / 1024);
+
+ if (mappable_end > ggtt->mappable_end ||
+ unmappable_base < ggtt->mappable_end ||
+ unmappable_end > ggtt_end) {
+ drm_err(&dev_priv->drm, "Invalid ballooning configuration!\n");
+ return -EINVAL;
+ }
+
+ /* Unmappable graphic memory ballooning */
+ if (unmappable_base > ggtt->mappable_end) {
+ ret = vgt_balloon_space(ggtt, &bl_info.space[2],
+ ggtt->mappable_end, unmappable_base);
+
+ if (ret)
+ goto err;
+ }
+
+ if (unmappable_end < ggtt_end) {
+ ret = vgt_balloon_space(ggtt, &bl_info.space[3],
+ unmappable_end, ggtt_end);
+ if (ret)
+ goto err_upon_mappable;
+ }
+
+ /* Mappable graphic memory ballooning */
+ if (mappable_base) {
+ ret = vgt_balloon_space(ggtt, &bl_info.space[0],
+ 0, mappable_base);
+
+ if (ret)
+ goto err_upon_unmappable;
+ }
+
+ if (mappable_end < ggtt->mappable_end) {
+ ret = vgt_balloon_space(ggtt, &bl_info.space[1],
+ mappable_end, ggtt->mappable_end);
+
+ if (ret)
+ goto err_below_mappable;
+ }
+
+ drm_info(&dev_priv->drm, "VGT balloon successfully\n");
+ return 0;
+
+err_below_mappable:
+ vgt_deballoon_space(ggtt, &bl_info.space[0]);
+err_upon_unmappable:
+ vgt_deballoon_space(ggtt, &bl_info.space[3]);
+err_upon_mappable:
+ vgt_deballoon_space(ggtt, &bl_info.space[2]);
+err:
+ drm_err(&dev_priv->drm, "VGT balloon fail\n");
+ return ret;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-04 03:32:02 +0000