xref: /openbmc/linux/drivers/gpu/drm/i915/intel_gvt.c (revision 4f6cce39)
1 /*
2  * Copyright(c) 2011-2016 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 "i915_drv.h"
25 #include "intel_gvt.h"
26 
27 /**
28  * DOC: Intel GVT-g host 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.
35  *
36  * To virtualize GPU resources GVT-g driver depends on hypervisor technology
37  * e.g KVM/VFIO/mdev, Xen, etc. to provide resource access trapping capability
38  * and be virtualized within GVT-g device module. More architectural design
39  * doc is available on https://01.org/group/2230/documentation-list.
40  */
41 
42 static bool is_supported_device(struct drm_i915_private *dev_priv)
43 {
44 	if (IS_BROADWELL(dev_priv))
45 		return true;
46 	if (IS_SKYLAKE(dev_priv))
47 		return true;
48 	return false;
49 }
50 
51 /**
52  * intel_gvt_init - initialize GVT components
53  * @dev_priv: drm i915 private data
54  *
55  * This function is called at the initialization stage to create a GVT device.
56  *
57  * Returns:
58  * Zero on success, negative error code if failed.
59  *
60  */
61 int intel_gvt_init(struct drm_i915_private *dev_priv)
62 {
63 	int ret;
64 
65 	if (!i915.enable_gvt) {
66 		DRM_DEBUG_DRIVER("GVT-g is disabled by kernel params\n");
67 		return 0;
68 	}
69 
70 	if (intel_vgpu_active(dev_priv)) {
71 		DRM_DEBUG_DRIVER("GVT-g is disabled for guest\n");
72 		goto bail;
73 	}
74 
75 	if (!is_supported_device(dev_priv)) {
76 		DRM_DEBUG_DRIVER("Unsupported device. GVT-g is disabled\n");
77 		goto bail;
78 	}
79 
80 	/*
81 	 * We're not in host or fail to find a MPT module, disable GVT-g
82 	 */
83 	ret = intel_gvt_init_host();
84 	if (ret) {
85 		DRM_DEBUG_DRIVER("Not in host or MPT modules not found\n");
86 		goto bail;
87 	}
88 
89 	ret = intel_gvt_init_device(dev_priv);
90 	if (ret) {
91 		DRM_DEBUG_DRIVER("Fail to init GVT device\n");
92 		goto bail;
93 	}
94 
95 	return 0;
96 
97 bail:
98 	i915.enable_gvt = 0;
99 	return 0;
100 }
101 
102 /**
103  * intel_gvt_cleanup - cleanup GVT components when i915 driver is unloading
104  * @dev_priv: drm i915 private *
105  *
106  * This function is called at the i915 driver unloading stage, to shutdown
107  * GVT components and release the related resources.
108  */
109 void intel_gvt_cleanup(struct drm_i915_private *dev_priv)
110 {
111 	if (!intel_gvt_active(dev_priv))
112 		return;
113 
114 	intel_gvt_clean_device(dev_priv);
115 }
116