[mirror_ubuntu-artful-kernel.git] / drivers / gpu / drm / i915 / i915_vgpu.c

/*
 * 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 "intel_drv.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.
 *
 */

/**
 * i915_check_vgpu - detect virtual GPU
 * @dev_priv: i915 device private
 *
 * This function is called at the initialization stage, to detect whether
 * running on a vGPU.
 */
void i915_check_vgpu(struct drm_i915_private *dev_priv)
{
	u64 magic;
	u16 version_major;

	BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE);

	magic = __raw_i915_read64(dev_priv, vgtif_reg(magic));
	if (magic != VGT_MAGIC)
		return;

	version_major = __raw_i915_read16(dev_priv, vgtif_reg(version_major));
	if (version_major < VGT_VERSION_MAJOR) {
		DRM_INFO("VGT interface version mismatch!\n");
		return;
	}

	dev_priv->vgpu.active = true;
	DRM_INFO("Virtual GPU for Intel GVT-g detected.\n");
}

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)
{
	DRM_DEBUG_DRIVER("deballoon space: range [0x%llx - 0x%llx] %llu KiB.\n",
			 node->start,
			 node->start + node->size,
			 node->size / 1024);

	ggtt->base.reserved -= node->size;
	drm_mm_remove_node(node);
}

/**
 * intel_vgt_deballoon - deballoon reserved graphics address trunks
 * @dev_priv: i915 device private data
 *
 * This function is called to deallocate the ballooned-out graphic memory, when
 * driver is unloaded or when ballooning fails.
 */
void intel_vgt_deballoon(struct drm_i915_private *dev_priv)
{
	int i;

	if (!intel_vgpu_active(dev_priv))
		return;

	DRM_DEBUG("VGT deballoon.\n");

	for (i = 0; i < 4; i++)
		vgt_deballoon_space(&dev_priv->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)
{
	unsigned long size = end - start;
	int ret;

	if (start >= end)
		return -EINVAL;

	DRM_INFO("balloon space: range [ 0x%lx - 0x%lx ] %lu KiB.\n",
		 start, end, size / 1024);
	ret = i915_gem_gtt_reserve(&ggtt->base, node,
				   size, start, I915_COLOR_UNEVICTABLE,
				   0);
	if (!ret)
		ggtt->base.reserved += size;

	return ret;
}

/**
 * intel_vgt_balloon - balloon out reserved graphics address trunks
 * @dev_priv: i915 device private data
 *
 * 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 drm_i915_private *dev_priv)
{
	struct i915_ggtt *ggtt = &dev_priv->ggtt;
	unsigned long ggtt_end = ggtt->base.total;

	unsigned long mappable_base, mappable_size, mappable_end;
	unsigned long unmappable_base, unmappable_size, unmappable_end;
	int ret;

	if (!intel_vgpu_active(dev_priv))
		return 0;

	mappable_base = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.base));
	mappable_size = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.size));
	unmappable_base = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.base));
	unmappable_size = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.size));

	mappable_end = mappable_base + mappable_size;
	unmappable_end = unmappable_base + unmappable_size;

	DRM_INFO("VGT ballooning configuration:\n");
	DRM_INFO("Mappable graphic memory: base 0x%lx size %ldKiB\n",
		 mappable_base, mappable_size / 1024);
	DRM_INFO("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_ERROR("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("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_ERROR("VGT balloon fail\n");
	return ret;
}
Commit	Line	Data
cf9d2890 YZ	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
14bb2c11	56	* @dev_priv: i915 device private
cf9d2890 YZ	57	*
	58	* This function is called at the initialization stage, to detect whether
	59	* running on a vGPU.
	60	*/
dc97997a	61	void i915_check_vgpu(struct drm_i915_private *dev_priv)
cf9d2890	62	{
0c8792d0 ZW	63	u64 magic;
0c8792d0 ZW	64	u16 version_major;
cf9d2890 YZ	65
	66	BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE);
	67
75aa3f63	68	magic = __raw_i915_read64(dev_priv, vgtif_reg(magic));
cf9d2890 YZ	69	if (magic != VGT_MAGIC)
	70	return;
	71
0c8792d0 ZW	72	version_major = __raw_i915_read16(dev_priv, vgtif_reg(version_major));
0c8792d0 ZW	73	if (version_major < VGT_VERSION_MAJOR) {
cf9d2890 YZ	74	DRM_INFO("VGT interface version mismatch!\n");
	75	return;
	76	}
	77
	78	dev_priv->vgpu.active = true;
	79	DRM_INFO("Virtual GPU for Intel GVT-g detected.\n");
	80	}
5dda8fa3 YZ	81
	82	struct _balloon_info_ {
	83	/*
	84	* There are up to 2 regions per mappable/unmappable graphic
	85	* memory that might be ballooned. Here, index 0/1 is for mappable
	86	* graphic memory, 2/3 for unmappable graphic memory.
	87	*/
	88	struct drm_mm_node space[4];
	89	};
	90
	91	static struct _balloon_info_ bl_info;
	92
ff8f7975 WL	93	static void vgt_deballoon_space(struct i915_ggtt *ggtt,
	94	struct drm_mm_node *node)
	95	{
	96	DRM_DEBUG_DRIVER("deballoon space: range [0x%llx - 0x%llx] %llu KiB.\n",
	97	node->start,
	98	node->start + node->size,
	99	node->size / 1024);
	100
	101	ggtt->base.reserved -= node->size;
	102	drm_mm_remove_node(node);
	103	}
	104
5dda8fa3 YZ	105	/**
5dda8fa3 YZ	106	* intel_vgt_deballoon - deballoon reserved graphics address trunks
62f90b38	107	* @dev_priv: i915 device private data
5dda8fa3 YZ	108	*
	109	* This function is called to deallocate the ballooned-out graphic memory, when
	110	* driver is unloaded or when ballooning fails.
	111	*/
b02d22a3	112	void intel_vgt_deballoon(struct drm_i915_private *dev_priv)
5dda8fa3 YZ	113	{
	114	int i;
	115
b02d22a3 ZW	116	if (!intel_vgpu_active(dev_priv))
	117	return;
	118
5dda8fa3 YZ	119	DRM_DEBUG("VGT deballoon.\n");
5dda8fa3 YZ	120
ff8f7975 WL	121	for (i = 0; i < 4; i++)
ff8f7975 WL	122	vgt_deballoon_space(&dev_priv->ggtt, &bl_info.space[i]);
5dda8fa3 YZ	123	}
5dda8fa3 YZ	124
625d988a	125	static int vgt_balloon_space(struct i915_ggtt *ggtt,
5dda8fa3 YZ	126	struct drm_mm_node *node,
	127	unsigned long start, unsigned long end)
	128	{
	129	unsigned long size = end - start;
ff8f7975	130	int ret;
5dda8fa3	131
b368f533	132	if (start >= end)
5dda8fa3 YZ	133	return -EINVAL;
	134
	135	DRM_INFO("balloon space: range [ 0x%lx - 0x%lx ] %lu KiB.\n",
	136	start, end, size / 1024);
ff8f7975 WL	137	ret = i915_gem_gtt_reserve(&ggtt->base, node,
	138	size, start, I915_COLOR_UNEVICTABLE,
	139	0);
	140	if (!ret)
	141	ggtt->base.reserved += size;
	142
	143	return ret;
5dda8fa3 YZ	144	}
	145
	146	/**
	147	* intel_vgt_balloon - balloon out reserved graphics address trunks
62f90b38	148	* @dev_priv: i915 device private data
5dda8fa3 YZ	149	*
	150	* This function is called at the initialization stage, to balloon out the
	151	* graphic address space allocated to other vGPUs, by marking these spaces as
	152	* reserved. The ballooning related knowledge(starting address and size of
	153	* the mappable/unmappable graphic memory) is described in the vgt_if structure
	154	* in a reserved mmio range.
	155	*
	156	* To give an example, the drawing below depicts one typical scenario after
	157	* ballooning. Here the vGPU1 has 2 pieces of graphic address spaces ballooned
	158	* out each for the mappable and the non-mappable part. From the vGPU1 point of
	159	* view, the total size is the same as the physical one, with the start address
	160	* of its graphic space being zero. Yet there are some portions ballooned out(
	161	* the shadow part, which are marked as reserved by drm allocator). From the
	162	* host point of view, the graphic address space is partitioned by multiple
da5335b8	163	* vGPUs in different VMs. ::
5dda8fa3	164	*
62cacc79 DV	165	* vGPU1 view Host view
	166	* 0 ------> +-----------+ +-----------+
	167	* ^ \|###########\| \| vGPU3 \|
	168	* \| \|###########\| +-----------+
	169	* \| \|###########\| \| vGPU2 \|
	170	* \| +-----------+ +-----------+
	171	* mappable GM \| available \| ==> \| vGPU1 \|
	172	* \| +-----------+ +-----------+
	173	* \| \|###########\| \| \|
	174	* v \|###########\| \| Host \|
	175	* +=======+===========+ +===========+
	176	* ^ \|###########\| \| vGPU3 \|
	177	* \| \|###########\| +-----------+
	178	* \| \|###########\| \| vGPU2 \|
	179	* \| +-----------+ +-----------+
	180	* unmappable GM \| available \| ==> \| vGPU1 \|
	181	* \| +-----------+ +-----------+
	182	* \| \|###########\| \| \|
	183	* \| \|###########\| \| Host \|
	184	* v \|###########\| \| \|
	185	* total GM size ------> +-----------+ +-----------+
5dda8fa3 YZ	186	*
	187	* Returns:
	188	* zero on success, non-zero if configuration invalid or ballooning failed
	189	*/
b02d22a3	190	int intel_vgt_balloon(struct drm_i915_private *dev_priv)
5dda8fa3	191	{
72e96d64	192	struct i915_ggtt *ggtt = &dev_priv->ggtt;
381b943b	193	unsigned long ggtt_end = ggtt->base.total;
5dda8fa3 YZ	194
	195	unsigned long mappable_base, mappable_size, mappable_end;
	196	unsigned long unmappable_base, unmappable_size, unmappable_end;
	197	int ret;
	198
b02d22a3 ZW	199	if (!intel_vgpu_active(dev_priv))
	200	return 0;
	201
5dda8fa3 YZ	202	mappable_base = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.base));
	203	mappable_size = I915_READ(vgtif_reg(avail_rs.mappable_gmadr.size));
	204	unmappable_base = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.base));
	205	unmappable_size = I915_READ(vgtif_reg(avail_rs.nonmappable_gmadr.size));
	206
	207	mappable_end = mappable_base + mappable_size;
	208	unmappable_end = unmappable_base + unmappable_size;
	209
	210	DRM_INFO("VGT ballooning configuration:\n");
	211	DRM_INFO("Mappable graphic memory: base 0x%lx size %ldKiB\n",
	212	mappable_base, mappable_size / 1024);
	213	DRM_INFO("Unmappable graphic memory: base 0x%lx size %ldKiB\n",
	214	unmappable_base, unmappable_size / 1024);
	215
381b943b	216	if (mappable_end > ggtt->mappable_end \|\|
72e96d64 JL	217	unmappable_base < ggtt->mappable_end \|\|
72e96d64 JL	218	unmappable_end > ggtt_end) {
5dda8fa3 YZ	219	DRM_ERROR("Invalid ballooning configuration!\n");
	220	return -EINVAL;
	221	}
	222
	223	/* Unmappable graphic memory ballooning */
72e96d64	224	if (unmappable_base > ggtt->mappable_end) {
625d988a CW	225	ret = vgt_balloon_space(ggtt, &bl_info.space[2],
625d988a CW	226	ggtt->mappable_end, unmappable_base);
5dda8fa3 YZ	227
	228	if (ret)
	229	goto err;
	230	}
	231
fa7e8b55	232	if (unmappable_end < ggtt_end) {
625d988a	233	ret = vgt_balloon_space(ggtt, &bl_info.space[3],
fa7e8b55	234	unmappable_end, ggtt_end);
5dda8fa3	235	if (ret)
ff8f7975	236	goto err_upon_mappable;
5dda8fa3 YZ	237	}
	238
	239	/* Mappable graphic memory ballooning */
381b943b	240	if (mappable_base) {
625d988a	241	ret = vgt_balloon_space(ggtt, &bl_info.space[0],
381b943b	242	0, mappable_base);
5dda8fa3 YZ	243
5dda8fa3 YZ	244	if (ret)
ff8f7975	245	goto err_upon_unmappable;
5dda8fa3 YZ	246	}
5dda8fa3 YZ	247
72e96d64	248	if (mappable_end < ggtt->mappable_end) {
625d988a CW	249	ret = vgt_balloon_space(ggtt, &bl_info.space[1],
625d988a CW	250	mappable_end, ggtt->mappable_end);
5dda8fa3 YZ	251
5dda8fa3 YZ	252	if (ret)
ff8f7975	253	goto err_below_mappable;
5dda8fa3 YZ	254	}
	255
	256	DRM_INFO("VGT balloon successfully\n");
	257	return 0;
	258
ff8f7975 WL	259	err_below_mappable:
	260	vgt_deballoon_space(ggtt, &bl_info.space[0]);
	261	err_upon_unmappable:
	262	vgt_deballoon_space(ggtt, &bl_info.space[3]);
	263	err_upon_mappable:
	264	vgt_deballoon_space(ggtt, &bl_info.space[2]);
5dda8fa3 YZ	265	err:
5dda8fa3 YZ	266	DRM_ERROR("VGT balloon fail\n");
5dda8fa3 YZ	267	return ret;
5dda8fa3 YZ	268	}