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

   1 /*
   2  * Copyright(c) 2011-2017 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 #include "i915_drv.h"
  24 #include "gvt.h"
  25
  26 /**
  27  * intel_vgpu_find_page_track - find page track rcord of guest page
  28  * @vgpu: a vGPU
  29  * @gfn: the gfn of guest page
  30  *
  31  * Returns:
  32  * A pointer to struct intel_vgpu_page_track if found, else NULL returned.
  33  */
  34 struct intel_vgpu_page_track *intel_vgpu_find_page_track(
  35                 struct intel_vgpu *vgpu, unsigned long gfn)
  36 {
  37         return radix_tree_lookup(&vgpu->page_track_tree, gfn);
  38 }
  39
  40 /**
  41  * intel_vgpu_register_page_track - register a guest page to be tacked
  42  * @vgpu: a vGPU
  43  * @gfn: the gfn of guest page
  44  *
  45  * Returns:
  46  * zero on success, negative error code if failed.
  47  */
  48 int intel_vgpu_register_page_track(struct intel_vgpu *vgpu, unsigned long gfn,
  49                 gvt_page_track_handler_t handler, void *priv)
  50 {
  51         struct intel_vgpu_page_track *track;
  52         int ret;
  53
  54         track = intel_vgpu_find_page_track(vgpu, gfn);
  55         if (track)
  56                 return -EEXIST;
  57
  58         track = kzalloc(sizeof(*track), GFP_KERNEL);
  59         if (!track)
  60                 return -ENOMEM;
  61
  62         track->handler = handler;
  63         track->priv_data = priv;
  64
  65         ret = radix_tree_insert(&vgpu->page_track_tree, gfn, track);
  66         if (ret) {
  67                 kfree(track);
  68                 return ret;
  69         }
  70
  71         return 0;
  72 }
  73
  74 /**
  75  * intel_vgpu_unregister_page_track - unregister the tracked guest page
  76  * @vgpu: a vGPU
  77  * @gfn: the gfn of guest page
  78  *
  79  */
  80 void intel_vgpu_unregister_page_track(struct intel_vgpu *vgpu,
  81                 unsigned long gfn)
  82 {
  83         struct intel_vgpu_page_track *track;
  84
  85         track = radix_tree_delete(&vgpu->page_track_tree, gfn);
  86         if (track) {
  87                 if (track->tracked)
  88                         intel_gvt_hypervisor_disable_page_track(vgpu, gfn);
  89                 kfree(track);
  90         }
  91 }
  92
  93 /**
  94  * intel_vgpu_enable_page_track - set write-protection on guest page
  95  * @vgpu: a vGPU
  96  * @gfn: the gfn of guest page
  97  *
  98  * Returns:
  99  * zero on success, negative error code if failed.
 100  */
 101 int intel_vgpu_enable_page_track(struct intel_vgpu *vgpu, unsigned long gfn)
 102 {
 103         struct intel_vgpu_page_track *track;
 104         int ret;
 105
 106         track = intel_vgpu_find_page_track(vgpu, gfn);
 107         if (!track)
 108                 return -ENXIO;
 109
 110         if (track->tracked)
 111                 return 0;
 112
 113         ret = intel_gvt_hypervisor_enable_page_track(vgpu, gfn);
 114         if (ret)
 115                 return ret;
 116         track->tracked = true;
 117         return 0;
 118 }
 119
 120 /**
 121  * intel_vgpu_enable_page_track - cancel write-protection on guest page
 122  * @vgpu: a vGPU
 123  * @gfn: the gfn of guest page
 124  *
 125  * Returns:
 126  * zero on success, negative error code if failed.
 127  */
 128 int intel_vgpu_disable_page_track(struct intel_vgpu *vgpu, unsigned long gfn)
 129 {
 130         struct intel_vgpu_page_track *track;
 131         int ret;
 132
 133         track = intel_vgpu_find_page_track(vgpu, gfn);
 134         if (!track)
 135                 return -ENXIO;
 136
 137         if (!track->tracked)
 138                 return 0;
 139
 140         ret = intel_gvt_hypervisor_disable_page_track(vgpu, gfn);
 141         if (ret)
 142                 return ret;
 143         track->tracked = false;
 144         return 0;
 145 }
 146
 147 /**
 148  * intel_vgpu_page_track_handler - called when write to write-protected page
 149  * @vgpu: a vGPU
 150  * @gpa: the gpa of this write
 151  * @data: the writed data
 152  * @bytes: the length of this write
 153  *
 154  * Returns:
 155  * zero on success, negative error code if failed.
 156  */
 157 int intel_vgpu_page_track_handler(struct intel_vgpu *vgpu, u64 gpa,
 158                 void *data, unsigned int bytes)
 159 {
 160         struct intel_vgpu_page_track *page_track;
 161         int ret = 0;
 162
 163         mutex_lock(&vgpu->vgpu_lock);
 164
 165         page_track = intel_vgpu_find_page_track(vgpu, gpa >> PAGE_SHIFT);
 166         if (!page_track) {
 167                 ret = -ENXIO;
 168                 goto out;
 169         }
 170
 171         if (unlikely(vgpu->failsafe)) {
 172                 /* Remove write protection to prevent furture traps. */
 173                 intel_vgpu_disable_page_track(vgpu, gpa >> PAGE_SHIFT);
 174         } else {
 175                 ret = page_track->handler(page_track, gpa, data, bytes);
 176                 if (ret)
 177                         gvt_err("guest page write error, gpa %llx\n", gpa);
 178         }
 179
 180 out:
 181         mutex_unlock(&vgpu->vgpu_lock);
 182         return ret;
 183 }