drm/i915/gvt: vGPU HW resource management

This patch introduces the GVT-g vGPU HW resource management. Under
GVT-g virtualizaion environment, each vGPU requires portions HW
resources, including aperture, hidden GM space, and fence registers.

When creating a vGPU, GVT-g will request these HW resources from host,
and return them to host after a vGPU is destroyed.

Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/Makefile

@@ -1,5 +1,5 @@
 GVT_DIR := gvt
-GVT_SOURCE := gvt.o
+GVT_SOURCE := gvt.o aperture_gm.o
 
 ccflags-y                      += -I$(src) -I$(src)/$(GVT_DIR) -Wall
 i915-y			       += $(addprefix $(GVT_DIR)/, $(GVT_SOURCE))

drivers/gpu/drm/i915/gvt/aperture_gm.c

@@ -0,0 +1,341 @@
+/*
+ * Copyright(c) 2011-2016 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.
+ *
+ * Authors:
+ *    Kevin Tian <kevin.tian@intel.com>
+ *    Dexuan Cui
+ *
+ * Contributors:
+ *    Pei Zhang <pei.zhang@intel.com>
+ *    Min He <min.he@intel.com>
+ *    Niu Bing <bing.niu@intel.com>
+ *    Yulei Zhang <yulei.zhang@intel.com>
+ *    Zhenyu Wang <zhenyuw@linux.intel.com>
+ *    Zhi Wang <zhi.a.wang@intel.com>
+ *
+ */
+
+#include "i915_drv.h"
+
+#define MB_TO_BYTES(mb) ((mb) << 20ULL)
+#define BYTES_TO_MB(b) ((b) >> 20ULL)
+
+#define HOST_LOW_GM_SIZE MB_TO_BYTES(128)
+#define HOST_HIGH_GM_SIZE MB_TO_BYTES(384)
+#define HOST_FENCE 4
+
+static int alloc_gm(struct intel_vgpu *vgpu, bool high_gm)
+{
+	struct intel_gvt *gvt = vgpu->gvt;
+	struct drm_i915_private *dev_priv = gvt->dev_priv;
+	u32 alloc_flag, search_flag;
+	u64 start, end, size;
+	struct drm_mm_node *node;
+	int retried = 0;
+	int ret;
+
+	if (high_gm) {
+		search_flag = DRM_MM_SEARCH_BELOW;
+		alloc_flag = DRM_MM_CREATE_TOP;
+		node = &vgpu->gm.high_gm_node;
+		size = vgpu_hidden_sz(vgpu);
+		start = gvt_hidden_gmadr_base(gvt);
+		end = gvt_hidden_gmadr_end(gvt);
+	} else {
+		search_flag = DRM_MM_SEARCH_DEFAULT;
+		alloc_flag = DRM_MM_CREATE_DEFAULT;
+		node = &vgpu->gm.low_gm_node;
+		size = vgpu_aperture_sz(vgpu);
+		start = gvt_aperture_gmadr_base(gvt);
+		end = gvt_aperture_gmadr_end(gvt);
+	}
+
+	mutex_lock(&dev_priv->drm.struct_mutex);
+search_again:
+	ret = drm_mm_insert_node_in_range_generic(&dev_priv->ggtt.base.mm,
+						  node, size, 4096, 0,
+						  start, end, search_flag,
+						  alloc_flag);
+	if (ret) {
+		ret = i915_gem_evict_something(&dev_priv->ggtt.base,
+					       size, 4096, 0, start, end, 0);
+		if (ret == 0 && ++retried < 3)
+			goto search_again;
+
+		gvt_err("fail to alloc %s gm space from host, retried %d\n",
+				high_gm ? "high" : "low", retried);
+	}
+	mutex_unlock(&dev_priv->drm.struct_mutex);
+	return ret;
+}
+
+static int alloc_vgpu_gm(struct intel_vgpu *vgpu)
+{
+	struct intel_gvt *gvt = vgpu->gvt;
+	struct drm_i915_private *dev_priv = gvt->dev_priv;
+	int ret;
+
+	ret = alloc_gm(vgpu, false);
+	if (ret)
+		return ret;
+
+	ret = alloc_gm(vgpu, true);
+	if (ret)
+		goto out_free_aperture;
+
+	gvt_dbg_core("vgpu%d: alloc low GM start %llx size %llx\n", vgpu->id,
+		     vgpu_aperture_offset(vgpu), vgpu_aperture_sz(vgpu));
+
+	gvt_dbg_core("vgpu%d: alloc high GM start %llx size %llx\n", vgpu->id,
+		     vgpu_hidden_offset(vgpu), vgpu_hidden_sz(vgpu));
+
+	return 0;
+out_free_aperture:
+	mutex_lock(&dev_priv->drm.struct_mutex);
+	drm_mm_remove_node(&vgpu->gm.low_gm_node);
+	mutex_unlock(&dev_priv->drm.struct_mutex);
+	return ret;
+}
+
+static void free_vgpu_gm(struct intel_vgpu *vgpu)
+{
+	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
+
+	mutex_lock(&dev_priv->drm.struct_mutex);
+	drm_mm_remove_node(&vgpu->gm.low_gm_node);
+	drm_mm_remove_node(&vgpu->gm.high_gm_node);
+	mutex_unlock(&dev_priv->drm.struct_mutex);
+}
+
+/**
+ * intel_vgpu_write_fence - write fence registers owned by a vGPU
+ * @vgpu: vGPU instance
+ * @fence: vGPU fence register number
+ * @value: Fence register value to be written
+ *
+ * This function is used to write fence registers owned by a vGPU. The vGPU
+ * fence register number will be translated into HW fence register number.
+ *
+ */
+void intel_vgpu_write_fence(struct intel_vgpu *vgpu,
+		u32 fence, u64 value)
+{
+	struct intel_gvt *gvt = vgpu->gvt;
+	struct drm_i915_private *dev_priv = gvt->dev_priv;
+	struct drm_i915_fence_reg *reg;
+	i915_reg_t fence_reg_lo, fence_reg_hi;
+
+	if (WARN_ON(fence > vgpu_fence_sz(vgpu)))
+		return;
+
+	reg = vgpu->fence.regs[fence];
+	if (WARN_ON(!reg))
+		return;
+
+	fence_reg_lo = FENCE_REG_GEN6_LO(reg->id);
+	fence_reg_hi = FENCE_REG_GEN6_HI(reg->id);
+
+	I915_WRITE(fence_reg_lo, 0);
+	POSTING_READ(fence_reg_lo);
+
+	I915_WRITE(fence_reg_hi, upper_32_bits(value));
+	I915_WRITE(fence_reg_lo, lower_32_bits(value));
+	POSTING_READ(fence_reg_lo);
+}
+
+static void free_vgpu_fence(struct intel_vgpu *vgpu)
+{
+	struct intel_gvt *gvt = vgpu->gvt;
+	struct drm_i915_private *dev_priv = gvt->dev_priv;
+	struct drm_i915_fence_reg *reg;
+	u32 i;
+
+	if (WARN_ON(!vgpu_fence_sz(vgpu)))
+		return;
+
+	mutex_lock(&dev_priv->drm.struct_mutex);
+	for (i = 0; i < vgpu_fence_sz(vgpu); i++) {
+		reg = vgpu->fence.regs[i];
+		intel_vgpu_write_fence(vgpu, i, 0);
+		list_add_tail(&reg->link,
+			      &dev_priv->mm.fence_list);
+	}
+	mutex_unlock(&dev_priv->drm.struct_mutex);
+}
+
+static int alloc_vgpu_fence(struct intel_vgpu *vgpu)
+{
+	struct intel_gvt *gvt = vgpu->gvt;
+	struct drm_i915_private *dev_priv = gvt->dev_priv;
+	struct drm_i915_fence_reg *reg;
+	int i;
+	struct list_head *pos, *q;
+
+	/* Request fences from host */
+	mutex_lock(&dev_priv->drm.struct_mutex);
+	i = 0;
+	list_for_each_safe(pos, q, &dev_priv->mm.fence_list) {
+		reg = list_entry(pos, struct drm_i915_fence_reg, link);
+		if (reg->pin_count || reg->vma)
+			continue;
+		list_del(pos);
+		vgpu->fence.regs[i] = reg;
+		intel_vgpu_write_fence(vgpu, i, 0);
+		if (++i == vgpu_fence_sz(vgpu))
+			break;
+	}
+	if (i != vgpu_fence_sz(vgpu))
+		goto out_free_fence;
+
+	mutex_unlock(&dev_priv->drm.struct_mutex);
+	return 0;
+out_free_fence:
+	/* Return fences to host, if fail */
+	for (i = 0; i < vgpu_fence_sz(vgpu); i++) {
+		reg = vgpu->fence.regs[i];
+		if (!reg)
+			continue;
+		list_add_tail(&reg->link,
+			      &dev_priv->mm.fence_list);
+	}
+	mutex_unlock(&dev_priv->drm.struct_mutex);
+	return -ENOSPC;
+}
+
+static void free_resource(struct intel_vgpu *vgpu)
+{
+	struct intel_gvt *gvt = vgpu->gvt;
+
+	gvt->gm.vgpu_allocated_low_gm_size -= vgpu_aperture_sz(vgpu);
+	gvt->gm.vgpu_allocated_high_gm_size -= vgpu_hidden_sz(vgpu);
+	gvt->fence.vgpu_allocated_fence_num -= vgpu_fence_sz(vgpu);
+}
+
+static int alloc_resource(struct intel_vgpu *vgpu,
+		struct intel_vgpu_creation_params *param)
+{
+	struct intel_gvt *gvt = vgpu->gvt;
+	unsigned long request, avail, max, taken;
+	const char *item;
+
+	if (!param->low_gm_sz || !param->high_gm_sz || !param->fence_sz) {
+		gvt_err("Invalid vGPU creation params\n");
+		return -EINVAL;
+	}
+
+	item = "low GM space";
+	max = gvt_aperture_sz(gvt) - HOST_LOW_GM_SIZE;
+	taken = gvt->gm.vgpu_allocated_low_gm_size;
+	avail = max - taken;
+	request = MB_TO_BYTES(param->low_gm_sz);
+
+	if (request > avail)
+		goto no_enough_resource;
+
+	vgpu_aperture_sz(vgpu) = request;
+
+	item = "high GM space";
+	max = gvt_hidden_sz(gvt) - HOST_HIGH_GM_SIZE;
+	taken = gvt->gm.vgpu_allocated_high_gm_size;
+	avail = max - taken;
+	request = MB_TO_BYTES(param->high_gm_sz);
+
+	if (request > avail)
+		goto no_enough_resource;
+
+	vgpu_hidden_sz(vgpu) = request;
+
+	item = "fence";
+	max = gvt_fence_sz(gvt) - HOST_FENCE;
+	taken = gvt->fence.vgpu_allocated_fence_num;
+	avail = max - taken;
+	request = param->fence_sz;
+
+	if (request > avail)
+		goto no_enough_resource;
+
+	vgpu_fence_sz(vgpu) = request;
+
+	gvt->gm.vgpu_allocated_low_gm_size += MB_TO_BYTES(param->low_gm_sz);
+	gvt->gm.vgpu_allocated_high_gm_size += MB_TO_BYTES(param->high_gm_sz);
+	gvt->fence.vgpu_allocated_fence_num += param->fence_sz;
+	return 0;
+
+no_enough_resource:
+	gvt_err("vgpu%d: fail to allocate resource %s\n", vgpu->id, item);
+	gvt_err("vgpu%d: request %luMB avail %luMB max %luMB taken %luMB\n",
+		vgpu->id, BYTES_TO_MB(request), BYTES_TO_MB(avail),
+		BYTES_TO_MB(max), BYTES_TO_MB(taken));
+	return -ENOSPC;
+}
+
+/**
+ * inte_gvt_free_vgpu_resource - free HW resource owned by a vGPU
+ * @vgpu: a vGPU
+ *
+ * This function is used to free the HW resource owned by a vGPU.
+ *
+ */
+void intel_vgpu_free_resource(struct intel_vgpu *vgpu)
+{
+	free_vgpu_gm(vgpu);
+	free_vgpu_fence(vgpu);
+	free_resource(vgpu);
+}
+
+/**
+ * intel_alloc_vgpu_resource - allocate HW resource for a vGPU
+ * @vgpu: vGPU
+ * @param: vGPU creation params
+ *
+ * This function is used to allocate HW resource for a vGPU. User specifies
+ * the resource configuration through the creation params.
+ *
+ * Returns:
+ * zero on success, negative error code if failed.
+ *
+ */
+int intel_vgpu_alloc_resource(struct intel_vgpu *vgpu,
+		struct intel_vgpu_creation_params *param)
+{
+	int ret;
+
+	ret = alloc_resource(vgpu, param);
+	if (ret)
+		return ret;
+
+	ret = alloc_vgpu_gm(vgpu);
+	if (ret)
+		goto out_free_resource;
+
+	ret = alloc_vgpu_fence(vgpu);
+	if (ret)
+		goto out_free_vgpu_gm;
+
+	return 0;
+
+out_free_vgpu_gm:
+	free_vgpu_gm(vgpu);
+out_free_resource:
+	free_resource(vgpu);
+	return ret;
+}

drivers/gpu/drm/i915/gvt/debug.h

@@ -24,6 +24,9 @@
 #ifndef __GVT_DEBUG_H__
 #define __GVT_DEBUG_H__
 
+#define gvt_err(fmt, args...) \
+	DRM_ERROR("gvt: "fmt, ##args)
+
 #define gvt_dbg_core(fmt, args...) \
 	DRM_DEBUG_DRIVER("gvt: core: "fmt, ##args)
 

drivers/gpu/drm/i915/gvt/gvt.c

@@ -84,7 +84,7 @@ int intel_gvt_init_host(void)
 
 static void init_device_info(struct intel_gvt *gvt)
 {
-	if (IS_BROADWELL(gvt->dev_priv))
+	if (IS_BROADWELL(gvt->dev_priv) || IS_SKYLAKE(gvt->dev_priv))
 		gvt->device_info.max_support_vgpus = 8;
 	/* This function will grow large in GVT device model patches. */
 }
@@ -135,6 +135,9 @@ int intel_gvt_init_device(struct drm_i915_private *dev_priv)
 
 	gvt_dbg_core("init gvt device\n");
 
+	mutex_init(&gvt->lock);
+	gvt->dev_priv = dev_priv;
+
 	init_device_info(gvt);
 	/*
 	 * Other initialization of GVT components will be introduce here.