drm/i915: gvt: Introduce the basic architecture of GVT-g

This patch introduces the very basic framework of GVT-g device model,
includes basic prototypes, definitions, initialization.

v12:
- Call intel_gvt_init() in driver early initialization stage. (Chris)

v8:
- Remove the GVT idr and mutex in intel_gvt_host. (Joonas)

v7:
- Refine the URL link in Kconfig. (Joonas)
- Refine the introduction of GVT-g host support in Kconfig. (Joonas)
- Remove the macro GVT_ALIGN(), use round_down() instead. (Joonas)
- Make "struct intel_gvt" a data member in struct drm_i915_private.(Joonas)
	- Remove {alloc, free}_gvt_device()
	- Rename intel_gvt_{create, destroy}_gvt_device()
	- Expost intel_gvt_init_host()
- Remove the dummy "struct intel_gvt" declaration in intel_gvt.h (Joonas)

v6:
- Refine introduction in Kconfig. (Chris)
- The exposed API functions will take struct intel_gvt * instead of
void *. (Chris/Tvrtko)
- Remove most memebers of strct intel_gvt_device_info. Will add them
in the device model patches.(Chris)
- Remove gvt_info() and gvt_err() in debug.h. (Chris)
- Move GVT kernel parameter into i915_params. (Chris)
- Remove include/drm/i915_gvt.h, as GVT-g will be built within i915.
- Remove the redundant struct i915_gvt *, as the functions in i915
will directly take struct intel_gvt *.
- Add more comments for reviewer.

v5:
Take Tvrtko's comments:
- Fix the misspelled words in Kconfig
- Let functions take drm_i915_private * instead of struct drm_device *
- Remove redundant prints/local varible initialization

v3:
Take Joonas' comments:
- Change file name i915_gvt.* to intel_gvt.*
- Move GVT kernel parameter into intel_gvt.c
- Remove redundant debug macros
- Change error handling style
- Add introductions for some stub functions
- Introduce drm/i915_gvt.h.

Take Kevin's comments:
- Move GVT-g host/guest check into intel_vgt_balloon in i915_gem_gtt.c

v2:
- Introduce i915_gvt.c.
It's necessary to introduce the stubs between i915 driver and GVT-g host,
as GVT-g components is configurable in kernel config. When disabled, the
stubs here do nothing.

Take Joonas' comments:
- Replace boolean return value with int.
- Replace customized info/warn/debug macros with DRM macros.
- Document all non-static functions like i915.
- Remove empty and unused functions.
- Replace magic number with marcos.
- Set GVT-g in kernel config to "n" by default.
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Zhi Wang <zhi.a.wang@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1466078825-6662-5-git-send-email-zhi.a.wang@intel.comSigned-off-by: Chris Wilson <chris@chris-wilson.co.uk>

drivers/gpu/drm/i915/Kconfig

@@ -57,6 +57,28 @@ config DRM_I915_USERPTR
 
 	  If in doubt, say "Y".
 
+config DRM_I915_GVT
+        bool "Enable Intel GVT-g graphics virtualization host support"
+        depends on DRM_I915
+        default n
+        help
+	  Choose this option if you want to enable Intel GVT-g graphics
+	  virtualization technology host support with integrated graphics.
+	  With GVT-g, it's possible to have one integrated graphics
+	  device shared by multiple VMs under different hypervisors.
+
+	  Note that at least one hypervisor like Xen or KVM is required for
+	  this driver to work, and it only supports newer device from
+	  Broadwell+. For further information and setup guide, you can
+	  visit: http://01.org/igvt-g.
+
+	  Now it's just a stub to support the modifications of i915 for
+	  GVT device model. It requires at least one MPT modules for Xen/KVM
+	  and other components of GVT device model to work. Use it under
+	  you own risk.
+
+	  If in doubt, say "N".
+
 menu "drm/i915 Debugging"
 depends on DRM_I915
 depends on EXPERT

drivers/gpu/drm/i915/Makefile

@@ -104,6 +104,11 @@ i915-y += i915_vgpu.o
 # legacy horrors
 i915-y += i915_dma.o
 
+ifeq ($(CONFIG_DRM_I915_GVT),y)
+i915-y += intel_gvt.o
+include $(src)/gvt/Makefile
+endif
+
 obj-$(CONFIG_DRM_I915)  += i915.o
 
 CFLAGS_i915_trace_points.o := -I$(src)

drivers/gpu/drm/i915/gvt/Makefile

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

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

+/*
+ * 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.
+ */
+
+#ifndef __GVT_DEBUG_H__
+#define __GVT_DEBUG_H__
+
+#define gvt_dbg_core(fmt, args...) \
+	DRM_DEBUG_DRIVER("gvt: core: "fmt, ##args)
+
+/*
+ * Other GVT debug stuff will be introduced in the GVT device model patches.
+ */
+
+#endif

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

+/*
+ * 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.
+ */
+
+#include <linux/types.h>
+#include <xen/xen.h>
+
+#include "i915_drv.h"
+
+struct intel_gvt_host intel_gvt_host;
+
+static const char * const supported_hypervisors[] = {
+	[INTEL_GVT_HYPERVISOR_XEN] = "XEN",
+	[INTEL_GVT_HYPERVISOR_KVM] = "KVM",
+};
+
+/**
+ * intel_gvt_init_host - Load MPT modules and detect if we're running in host
+ * @gvt: intel gvt device
+ *
+ * This function is called at the driver loading stage. If failed to find a
+ * loadable MPT module or detect currently we're running in a VM, then GVT-g
+ * will be disabled
+ *
+ * Returns:
+ * Zero on success, negative error code if failed.
+ *
+ */
+int intel_gvt_init_host(void)
+{
+	if (intel_gvt_host.initialized)
+		return 0;
+
+	/* Xen DOM U */
+	if (xen_domain() && !xen_initial_domain())
+		return -ENODEV;
+
+	/* Try to load MPT modules for hypervisors */
+	if (xen_initial_domain()) {
+		/* In Xen dom0 */
+		intel_gvt_host.mpt = try_then_request_module(
+				symbol_get(xengt_mpt), "xengt");
+		intel_gvt_host.hypervisor_type = INTEL_GVT_HYPERVISOR_XEN;
+	} else {
+		/* not in Xen. Try KVMGT */
+		intel_gvt_host.mpt = try_then_request_module(
+				symbol_get(kvmgt_mpt), "kvm");
+		intel_gvt_host.hypervisor_type = INTEL_GVT_HYPERVISOR_KVM;
+	}
+
+	/* Fail to load MPT modules - bail out */
+	if (!intel_gvt_host.mpt)
+		return -EINVAL;
+
+	/* Try to detect if we're running in host instead of VM. */
+	if (!intel_gvt_hypervisor_detect_host())
+		return -ENODEV;
+
+	gvt_dbg_core("Running with hypervisor %s in host mode\n",
+			supported_hypervisors[intel_gvt_host.hypervisor_type]);
+
+	intel_gvt_host.initialized = true;
+	return 0;
+}
+
+static void init_device_info(struct intel_gvt *gvt)
+{
+	if (IS_BROADWELL(gvt->dev_priv))
+		gvt->device_info.max_support_vgpus = 8;
+	/* This function will grow large in GVT device model patches. */
+}
+
+/**
+ * intel_gvt_clean_device - clean a GVT device
+ * @gvt: intel gvt device
+ *
+ * This function is called at the driver unloading stage, to free the
+ * resources owned by a GVT device.
+ *
+ */
+void intel_gvt_clean_device(struct drm_i915_private *dev_priv)
+{
+	struct intel_gvt *gvt = &dev_priv->gvt;
+
+	if (WARN_ON(!gvt->initialized))
+		return;
+
+	/* Other de-initialization of GVT components will be introduced. */
+
+	gvt->initialized = false;
+}
+
+/**
+ * intel_gvt_init_device - initialize a GVT device
+ * @dev_priv: drm i915 private data
+ *
+ * This function is called at the initialization stage, to initialize
+ * necessary GVT components.
+ *
+ * Returns:
+ * Zero on success, negative error code if failed.
+ *
+ */
+int intel_gvt_init_device(struct drm_i915_private *dev_priv)
+{
+	struct intel_gvt *gvt = &dev_priv->gvt;
+	/*
+	 * Cannot initialize GVT device without intel_gvt_host gets
+	 * initialized first.
+	 */
+	if (WARN_ON(!intel_gvt_host.initialized))
+		return -EINVAL;
+
+	if (WARN_ON(gvt->initialized))
+		return -EEXIST;
+
+	gvt_dbg_core("init gvt device\n");
+
+	init_device_info(gvt);
+	/*
+	 * Other initialization of GVT components will be introduce here.
+	 */
+	gvt_dbg_core("gvt device creation is done\n");
+	gvt->initialized = true;
+	return 0;
+}

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

+/*
+ * 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.
+ */
+
+#ifndef _GVT_H_
+#define _GVT_H_
+
+#include "debug.h"
+#include "hypercall.h"
+
+#define GVT_MAX_VGPU 8
+
+enum {
+	INTEL_GVT_HYPERVISOR_XEN = 0,
+	INTEL_GVT_HYPERVISOR_KVM,
+};
+
+struct intel_gvt_host {
+	bool initialized;
+	int hypervisor_type;
+	struct intel_gvt_mpt *mpt;
+};
+
+extern struct intel_gvt_host intel_gvt_host;
+
+/* Describe per-platform limitations. */
+struct intel_gvt_device_info {
+	u32 max_support_vgpus;
+	/* This data structure will grow bigger in GVT device model patches */
+};
+
+struct intel_vgpu {
+	struct intel_gvt *gvt;
+	int id;
+	unsigned long handle; /* vGPU handle used by hypervisor MPT modules */
+};
+
+struct intel_gvt {
+	struct mutex lock;
+	bool initialized;
+
+	struct drm_i915_private *dev_priv;
+	struct idr vgpu_idr;	/* vGPU IDR pool */
+
+	struct intel_gvt_device_info device_info;
+};
+
+#include "mpt.h"
+
+#endif

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

+/*
+ * 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.
+ */
+
+#ifndef _GVT_HYPERCALL_H_
+#define _GVT_HYPERCALL_H_
+
+/*
+ * Specific GVT-g MPT modules function collections. Currently GVT-g supports
+ * both Xen and KVM by providing dedicated hypervisor-related MPT modules.
+ */
+struct intel_gvt_mpt {
+	int (*detect_host)(void);
+};
+
+extern struct intel_gvt_mpt xengt_mpt;
+extern struct intel_gvt_mpt kvmgt_mpt;
+
+#endif /* _GVT_HYPERCALL_H_ */

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

+/*
+ * 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.
+ */
+
+#ifndef _GVT_MPT_H_
+#define _GVT_MPT_H_
+
+/**
+ * DOC: Hypervisor Service APIs for GVT-g Core Logic
+ *
+ * This is the glue layer between specific hypervisor MPT modules and GVT-g core
+ * logic. Each kind of hypervisor MPT module provides a collection of function
+ * callbacks and will be attached to GVT host when the driver is loading.
+ * GVT-g core logic will call these APIs to request specific services from
+ * hypervisor.
+ */
+
+/**
+ * intel_gvt_hypervisor_detect_host - check if GVT-g is running within
+ * hypervisor host/privilged domain
+ *
+ * Returns:
+ * Zero on success, -ENODEV if current kernel is running inside a VM
+ */
+static inline int intel_gvt_hypervisor_detect_host(void)
+{
+	return intel_gvt_host.mpt->detect_host();
+}
+
+#endif /* _GVT_MPT_H_ */

drivers/gpu/drm/i915/i915_dma.c

@@ -1120,6 +1120,10 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
 	if (ret < 0)
 		return ret;
 
+	ret = intel_gvt_init(dev_priv);
+	if (ret < 0)
+		goto err_workqueues;
+
 	/* This must be called before any calls to HAS_PCH_* */
 	intel_detect_pch(dev);
 
@@ -1145,6 +1149,10 @@ static int i915_driver_init_early(struct drm_i915_private *dev_priv,
 			 "It may not be fully functional.\n");
 
 	return 0;
+
+err_workqueues:
+	i915_workqueues_cleanup(dev_priv);
+	return ret;
 }
 
 /**
@@ -1516,6 +1524,8 @@ int i915_driver_unload(struct drm_device *dev)
 
 	intel_fbdev_fini(dev);
 
+	intel_gvt_cleanup(dev_priv);
+
 	ret = i915_gem_suspend(dev);
 	if (ret) {
 		DRM_ERROR("failed to idle hardware: %d\n", ret);

drivers/gpu/drm/i915/i915_drv.h

@@ -61,6 +61,8 @@
 #include "i915_gem_gtt.h"
 #include "i915_gem_render_state.h"
 
+#include "intel_gvt.h"
+
 /* General customization:
  */
 
@@ -1741,6 +1743,8 @@ struct drm_i915_private {
 
 	struct i915_virtual_gpu vgpu;
 
+	struct intel_gvt gvt;
+
 	struct intel_guc guc;
 
 	struct intel_csr csr;
@@ -2953,6 +2957,12 @@ void intel_uncore_forcewake_put__locked(struct drm_i915_private *dev_priv,
 u64 intel_uncore_edram_size(struct drm_i915_private *dev_priv);
 
 void assert_forcewakes_inactive(struct drm_i915_private *dev_priv);
+
+static inline bool intel_gvt_active(struct drm_i915_private *dev_priv)
+{
+	return dev_priv->gvt.initialized;
+}
+
 static inline bool intel_vgpu_active(struct drm_i915_private *dev_priv)
 {
 	return dev_priv->vgpu.active;

drivers/gpu/drm/i915/i915_params.c

@@ -60,6 +60,7 @@ struct i915_params i915 __read_mostly = {
 	.enable_dp_mst = true,
 	.inject_load_failure = 0,
 	.enable_dpcd_backlight = false,
+	.enable_gvt = false,
 };
 
 module_param_named(modeset, i915.modeset, int, 0400);
@@ -222,3 +223,7 @@ MODULE_PARM_DESC(inject_load_failure,
 module_param_named(enable_dpcd_backlight, i915.enable_dpcd_backlight, bool, 0600);
 MODULE_PARM_DESC(enable_dpcd_backlight,
 	"Enable support for DPCD backlight control (default:false)");
+
+module_param_named(enable_gvt, i915.enable_gvt, bool, 0600);
+MODULE_PARM_DESC(enable_gvt,
+	"Enable support for Intel GVT-g graphics virtualization host support(default:false)");

drivers/gpu/drm/i915/i915_params.h

@@ -63,6 +63,7 @@ struct i915_params {
 	bool nuclear_pageflip;
 	bool enable_dp_mst;
 	bool enable_dpcd_backlight;
+	bool enable_gvt;
 };
 
 extern struct i915_params i915 __read_mostly;

drivers/gpu/drm/i915/intel_gvt.c

+/*
+ * 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.
+ */
+
+#include "i915_drv.h"
+#include "intel_gvt.h"
+
+/**
+ * DOC: Intel GVT-g host 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 the englightments
+ * of GVT and the necessary components used by GVT in i915 driver.
+ */
+
+static bool is_supported_device(struct drm_i915_private *dev_priv)
+{
+	if (IS_BROADWELL(dev_priv))
+		return true;
+	return false;
+}
+
+/**
+ * intel_gvt_init - initialize GVT components
+ * @dev_priv: drm i915 private data
+ *
+ * This function is called at the initialization stage to create a GVT device.
+ *
+ * Returns:
+ * Zero on success, negative error code if failed.
+ *
+ */
+int intel_gvt_init(struct drm_i915_private *dev_priv)
+{
+	int ret;
+
+	if (!i915.enable_gvt) {
+		DRM_DEBUG_DRIVER("GVT-g is disabled by kernel params\n");
+		return 0;
+	}
+
+	if (!is_supported_device(dev_priv)) {
+		DRM_DEBUG_DRIVER("Unsupported device. GVT-g is disabled\n");
+		return 0;
+	}
+
+	/*
+	 * We're not in host or fail to find a MPT module, disable GVT-g
+	 */
+	ret = intel_gvt_init_host();
+	if (ret) {
+		DRM_DEBUG_DRIVER("Not in host or MPT modules not found\n");
+		return 0;
+	}
+
+	ret = intel_gvt_init_device(dev_priv);
+	if (ret) {
+		DRM_DEBUG_DRIVER("Fail to init GVT device\n");
+		return 0;
+	}
+
+	return 0;
+}
+
+/**
+ * intel_gvt_cleanup - cleanup GVT components when i915 driver is unloading
+ * @dev_priv: drm i915 private *
+ *
+ * This function is called at the i915 driver unloading stage, to shutdown
+ * GVT components and release the related resources.
+ */
+void intel_gvt_cleanup(struct drm_i915_private *dev_priv)
+{
+	if (!intel_gvt_active(dev_priv))
+		return;
+
+	intel_gvt_clean_device(dev_priv);
+}

drivers/gpu/drm/i915/intel_gvt.h

+/*
+ * 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.
+ */
+
+#ifndef _INTEL_GVT_H_
+#define _INTEL_GVT_H_
+
+#include "gvt/gvt.h"
+
+#ifdef CONFIG_DRM_I915_GVT
+int intel_gvt_init(struct drm_i915_private *dev_priv);
+void intel_gvt_cleanup(struct drm_i915_private *dev_priv);
+int intel_gvt_init_device(struct drm_i915_private *dev_priv);
+void intel_gvt_clean_device(struct drm_i915_private *dev_priv);
+int intel_gvt_init_host(void);
+#else
+static inline int intel_gvt_init(struct drm_i915_private *dev_priv)
+{
+	return 0;
+}
+static inline void intel_gvt_cleanup(struct drm_i915_private *dev_priv)
+{
+}
+#endif
+
+#endif /* _INTEL_GVT_H_ */