OvmfPkg/VirtioGpuDxe/Commands.c

   1 /** @file
   2
   3   VirtIo GPU initialization, and commands (primitives) for the GPU device.
   4
   5   Copyright (C) 2016, Red Hat, Inc.
   6
   7   This program and the accompanying materials are licensed and made available
   8   under the terms and conditions of the BSD License which accompanies this
   9   distribution. The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
  13   WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 #include <IndustryStandard/VirtioGpu.h>
  18 #include <Library/VirtioLib.h>
  19
  20 #include "VirtioGpu.h"
  21
  22 /**
  23   Configure the VirtIo GPU device that underlies VgpuDev.
  24
  25   @param[in,out] VgpuDev  The VGPU_DEV object to set up VirtIo messaging for.
  26                           On input, the caller is responsible for having
  27                           initialized VgpuDev->VirtIo. On output, VgpuDev->Ring
  28                           has been initialized, and synchronous VirtIo GPU
  29                           commands (primitives) can be submitted to the device.
  30
  31   @retval EFI_SUCCESS      VirtIo GPU configuration successful.
  32
  33   @retval EFI_UNSUPPORTED  The host-side configuration of the VirtIo GPU is not
  34                            supported by this driver.
  35
  36   @retval                  Error codes from underlying functions.
  37 **/
  38 EFI_STATUS
  39 VirtioGpuInit (
  40   IN OUT VGPU_DEV *VgpuDev
  41   )
  42 {
  43   UINT8      NextDevStat;
  44   EFI_STATUS Status;
  45   UINT64     Features;
  46   UINT16     QueueSize;
  47
  48   //
  49   // Execute virtio-v1.0-cs04, 3.1.1 Driver Requirements: Device
  50   // Initialization.
  51   //
  52   // 1. Reset the device.
  53   //
  54   NextDevStat = 0;
  55   Status = VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, NextDevStat);
  56   if (EFI_ERROR (Status)) {
  57     goto Failed;
  58   }
  59
  60   //
  61   // 2. Set the ACKNOWLEDGE status bit [...]
  62   //
  63   NextDevStat |= VSTAT_ACK;
  64   Status = VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, NextDevStat);
  65   if (EFI_ERROR (Status)) {
  66     goto Failed;
  67   }
  68
  69   //
  70   // 3. Set the DRIVER status bit [...]
  71   //
  72   NextDevStat |= VSTAT_DRIVER;
  73   Status = VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, NextDevStat);
  74   if (EFI_ERROR (Status)) {
  75     goto Failed;
  76   }
  77
  78   //
  79   // 4. Read device feature bits...
  80   //
  81   Status = VgpuDev->VirtIo->GetDeviceFeatures (VgpuDev->VirtIo, &Features);
  82   if (EFI_ERROR (Status)) {
  83     goto Failed;
  84   }
  85   if ((Features & VIRTIO_F_VERSION_1) == 0) {
  86     Status = EFI_UNSUPPORTED;
  87     goto Failed;
  88   }
  89   //
  90   // We only want the most basic 2D features.
  91   //
  92   Features &= VIRTIO_F_VERSION_1;
  93
  94   //
  95   // ... and write the subset of feature bits understood by the [...] driver to
  96   // the device. [...]
  97   // 5. Set the FEATURES_OK status bit.
  98   // 6. Re-read device status to ensure the FEATURES_OK bit is still set [...]
  99   //
 100   Status = Virtio10WriteFeatures (VgpuDev->VirtIo, Features, &NextDevStat);
 101   if (EFI_ERROR (Status)) {
 102     goto Failed;
 103   }
 104
 105   //
 106   // 7. Perform device-specific setup, including discovery of virtqueues for
 107   // the device [...]
 108   //
 109   Status = VgpuDev->VirtIo->SetQueueSel (VgpuDev->VirtIo,
 110                               VIRTIO_GPU_CONTROL_QUEUE);
 111   if (EFI_ERROR (Status)) {
 112     goto Failed;
 113   }
 114   Status = VgpuDev->VirtIo->GetQueueNumMax (VgpuDev->VirtIo, &QueueSize);
 115   if (EFI_ERROR (Status)) {
 116     goto Failed;
 117   }
 118
 119   //
 120   // We implement each VirtIo GPU command that we use with two descriptors:
 121   // request, response.
 122   //
 123   if (QueueSize < 2) {
 124     Status = EFI_UNSUPPORTED;
 125     goto Failed;
 126   }
 127
 128   //
 129   // [...] population of virtqueues [...]
 130   //
 131   Status = VirtioRingInit (QueueSize, &VgpuDev->Ring);
 132   if (EFI_ERROR (Status)) {
 133     goto Failed;
 134   }
 135   Status = VgpuDev->VirtIo->SetQueueAddress (VgpuDev->VirtIo, &VgpuDev->Ring);
 136   if (EFI_ERROR (Status)) {
 137     goto ReleaseQueue;
 138   }
 139
 140   //
 141   // 8. Set the DRIVER_OK status bit.
 142   //
 143   NextDevStat |= VSTAT_DRIVER_OK;
 144   Status = VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, NextDevStat);
 145   if (EFI_ERROR (Status)) {
 146     goto ReleaseQueue;
 147   }
 148
 149   return EFI_SUCCESS;
 150
 151 ReleaseQueue:
 152   VirtioRingUninit (&VgpuDev->Ring);
 153
 154 Failed:
 155   //
 156   // If any of these steps go irrecoverably wrong, the driver SHOULD set the
 157   // FAILED status bit to indicate that it has given up on the device (it can
 158   // reset the device later to restart if desired). [...]
 159   //
 160   // VirtIo access failure here should not mask the original error.
 161   //
 162   NextDevStat |= VSTAT_FAILED;
 163   VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, NextDevStat);
 164
 165   return Status;
 166 }
 167
 168 /**
 169   De-configure the VirtIo GPU device that underlies VgpuDev.
 170
 171   @param[in,out] VgpuDev  The VGPU_DEV object to tear down VirtIo messaging
 172                           for. On input, the caller is responsible for having
 173                           called VirtioGpuInit(). On output, VgpuDev->Ring has
 174                           been uninitialized; VirtIo GPU commands (primitives)
 175                           can no longer be submitted to the device.
 176 **/
 177 VOID
 178 VirtioGpuUninit (
 179   IN OUT VGPU_DEV *VgpuDev
 180   )
 181 {
 182   //
 183   // Resetting the VirtIo device makes it release its resources and forget its
 184   // configuration.
 185   //
 186   VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, 0);
 187   VirtioRingUninit (&VgpuDev->Ring);
 188 }
 189
 190 /**
 191   EFI_EVENT_NOTIFY function for the VGPU_DEV.ExitBoot event. It resets the
 192   VirtIo device, causing it to release its resources and to forget its
 193   configuration.
 194
 195   This function may only be called (that is, VGPU_DEV.ExitBoot may only be
 196   signaled) after VirtioGpuInit() returns and before VirtioGpuUninit() is
 197   called.
 198
 199   @param[in] Event    Event whose notification function is being invoked.
 200
 201   @param[in] Context  Pointer to the associated VGPU_DEV object.
 202 **/
 203 VOID
 204 EFIAPI
 205 VirtioGpuExitBoot (
 206   IN EFI_EVENT Event,
 207   IN VOID      *Context
 208   )
 209 {
 210   VGPU_DEV *VgpuDev;
 211
 212   VgpuDev = Context;
 213   VgpuDev->VirtIo->SetDeviceStatus (VgpuDev->VirtIo, 0);
 214 }