OvmfPkg/Include/Library/VirtioLib.h

   1 /** @file
   2
   3   Declarations of utility functions used by virtio device drivers.
   4
   5   Copyright (C) 2012-2016, Red Hat, Inc.
   6   Copyright (C) 2017, AMD Inc, All rights reserved.<BR>
   7
   8   This program and the accompanying materials are licensed and made available
   9   under the terms and conditions of the BSD License which accompanies this
  10   distribution. The full text of the license may be found at
  11   http://opensource.org/licenses/bsd-license.php
  12
  13   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
  14   WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  15
  16 **/
  17
  18 #ifndef _VIRTIO_LIB_H_
  19 #define _VIRTIO_LIB_H_
  20
  21 #include <Protocol/VirtioDevice.h>
  22
  23 #include <IndustryStandard/Virtio.h>
  24
  25
  26 /**
  27
  28   Configure a virtio ring.
  29
  30   This function sets up internal storage (the guest-host communication area)
  31   and lays out several "navigation" (ie. no-ownership) pointers to parts of
  32   that storage.
  33
  34   Relevant sections from the virtio-0.9.5 spec:
  35   - 1.1 Virtqueues,
  36   - 2.3 Virtqueue Configuration.
  37
  38   @param[in]  VirtIo            The virtio device which will use the ring.
  39
  40   @param[in]                    The number of descriptors to allocate for the
  41                                 virtio ring, as requested by the host.
  42
  43   @param[out] Ring              The virtio ring to set up.
  44
  45   @retval EFI_OUT_OF_RESOURCES  AllocatePages() failed to allocate contiguous
  46                                 pages for the requested QueueSize. Fields of
  47                                 Ring have indeterminate value.
  48
  49   @retval EFI_SUCCESS           Allocation and setup successful. Ring->Base
  50                                 (and nothing else) is responsible for
  51                                 deallocation.
  52
  53 **/
  54 EFI_STATUS
  55 EFIAPI
  56 VirtioRingInit (
  57   IN  VIRTIO_DEVICE_PROTOCOL *VirtIo,
  58   IN  UINT16                 QueueSize,
  59   OUT VRING                  *Ring
  60   );
  61
  62
  63 /**
  64
  65   Tear down the internal resources of a configured virtio ring.
  66
  67   The caller is responsible to stop the host from using this ring before
  68   invoking this function: the VSTAT_DRIVER_OK bit must be clear in
  69   VhdrDeviceStatus.
  70
  71   @param[in]  VirtIo  The virtio device which was using the ring.
  72
  73   @param[out] Ring    The virtio ring to clean up.
  74
  75 **/
  76 VOID
  77 EFIAPI
  78 VirtioRingUninit (
  79   IN     VIRTIO_DEVICE_PROTOCOL *VirtIo,
  80   IN OUT VRING                  *Ring
  81   );
  82
  83
  84 //
  85 // Internal use structure for tracking the submission of a multi-descriptor
  86 // request.
  87 //
  88 typedef struct {
  89   UINT16 HeadDescIdx;
  90   UINT16 NextDescIdx;
  91 } DESC_INDICES;
  92
  93
  94 /**
  95
  96   Turn off interrupt notifications from the host, and prepare for appending
  97   multiple descriptors to the virtio ring.
  98
  99   The calling driver must be in VSTAT_DRIVER_OK state.
 100
 101   @param[in,out] Ring  The virtio ring we intend to append descriptors to.
 102
 103   @param[out] Indices  The DESC_INDICES structure to initialize.
 104
 105 **/
 106 VOID
 107 EFIAPI
 108 VirtioPrepare (
 109   IN OUT VRING        *Ring,
 110   OUT    DESC_INDICES *Indices
 111   );
 112
 113
 114 /**
 115
 116   Append a contiguous buffer for transmission / reception via the virtio ring.
 117
 118   This function implements the following section from virtio-0.9.5:
 119   - 2.4.1.1 Placing Buffers into the Descriptor Table
 120
 121   Free space is taken as granted, since the individual drivers support only
 122   synchronous requests and host side status is processed in lock-step with
 123   request submission. It is the calling driver's responsibility to verify the
 124   ring size in advance.
 125
 126   The caller is responsible for initializing *Indices with VirtioPrepare()
 127   first.
 128
 129   @param[in,out] Ring        The virtio ring to append the buffer to, as a
 130                              descriptor.
 131
 132   @param[in] BufferPhysAddr  (Guest pseudo-physical) start address of the
 133                              transmit / receive buffer.
 134
 135   @param[in] BufferSize      Number of bytes to transmit or receive.
 136
 137   @param[in] Flags           A bitmask of VRING_DESC_F_* flags. The caller
 138                              computes this mask dependent on further buffers to
 139                              append and transfer direction.
 140                              VRING_DESC_F_INDIRECT is unsupported. The
 141                              VRING_DESC.Next field is always set, but the host
 142                              only interprets it dependent on VRING_DESC_F_NEXT.
 143
 144   @param[in,out] Indices     Indices->HeadDescIdx is not accessed.
 145                              On input, Indices->NextDescIdx identifies the next
 146                              descriptor to carry the buffer. On output,
 147                              Indices->NextDescIdx is incremented by one, modulo
 148                              2^16.
 149
 150 **/
 151 VOID
 152 EFIAPI
 153 VirtioAppendDesc (
 154   IN OUT VRING        *Ring,
 155   IN     UINTN        BufferPhysAddr,
 156   IN     UINT32       BufferSize,
 157   IN     UINT16       Flags,
 158   IN OUT DESC_INDICES *Indices
 159   );
 160
 161
 162 /**
 163
 164   Notify the host about the descriptor chain just built, and wait until the
 165   host processes it.
 166
 167   @param[in] VirtIo       The target virtio device to notify.
 168
 169   @param[in] VirtQueueId  Identifies the queue for the target device.
 170
 171   @param[in,out] Ring     The virtio ring with descriptors to submit.
 172
 173   @param[in] Indices      Indices->NextDescIdx is not accessed.
 174                           Indices->HeadDescIdx identifies the head descriptor
 175                           of the descriptor chain.
 176
 177   @param[out] UsedLen     On success, the total number of bytes, consecutively
 178                           across the buffers linked by the descriptor chain,
 179                           that the host wrote. May be NULL if the caller
 180                           doesn't care, or can compute the same information
 181                           from device-specific request structures linked by the
 182                           descriptor chain.
 183
 184   @return              Error code from VirtIo->SetQueueNotify() if it fails.
 185
 186   @retval EFI_SUCCESS  Otherwise, the host processed all descriptors.
 187
 188 **/
 189 EFI_STATUS
 190 EFIAPI
 191 VirtioFlush (
 192   IN     VIRTIO_DEVICE_PROTOCOL *VirtIo,
 193   IN     UINT16                 VirtQueueId,
 194   IN OUT VRING                  *Ring,
 195   IN     DESC_INDICES           *Indices,
 196   OUT    UINT32                 *UsedLen    OPTIONAL
 197   );
 198
 199
 200 /**
 201
 202   Report the feature bits to the VirtIo 1.0 device that the VirtIo 1.0 driver
 203   understands.
 204
 205   In VirtIo 1.0, a device can reject a self-inconsistent feature bitmap through
 206   the new VSTAT_FEATURES_OK status bit. (For example if the driver requests a
 207   higher level feature but clears a prerequisite feature.) This function is a
 208   small wrapper around VIRTIO_DEVICE_PROTOCOL.SetGuestFeatures() that also
 209   verifies if the VirtIo 1.0 device accepts the feature bitmap.
 210
 211   @param[in]     VirtIo        Report feature bits to this device.
 212
 213   @param[in]     Features      The set of feature bits that the driver wishes
 214                                to report. The caller is responsible to perform
 215                                any masking before calling this function; the
 216                                value is directly written with
 217                                VIRTIO_DEVICE_PROTOCOL.SetGuestFeatures().
 218
 219   @param[in,out] DeviceStatus  On input, the status byte most recently written
 220                                to the device's status register. On output (even
 221                                on error), DeviceStatus will be updated so that
 222                                it is suitable for further status bit
 223                                manipulation and writing to the device's status
 224                                register.
 225
 226   @retval  EFI_SUCCESS      The device accepted the configuration in Features.
 227
 228   @return  EFI_UNSUPPORTED  The device rejected the configuration in Features.
 229
 230   @retval  EFI_UNSUPPORTED  VirtIo->Revision is smaller than 1.0.0.
 231
 232   @return                   Error codes from the SetGuestFeatures(),
 233                             SetDeviceStatus(), GetDeviceStatus() member
 234                             functions.
 235
 236 **/
 237 EFI_STATUS
 238 EFIAPI
 239 Virtio10WriteFeatures (
 240   IN     VIRTIO_DEVICE_PROTOCOL *VirtIo,
 241   IN     UINT64                 Features,
 242   IN OUT UINT8                  *DeviceStatus
 243   );
 244
 245 /**
 246   Provides the virtio device address required to access system memory from a
 247   DMA bus master.
 248
 249   The interface follows the same usage pattern as defined in UEFI spec 2.6
 250   (Section 13.2 PCI Root Bridge I/O Protocol)
 251
 252   The VirtioMapAllBytesInSharedBuffer() is similar to VIRTIO_MAP_SHARED
 253   with exception that NumberOfBytes is IN-only parameter. The function
 254   maps all the bytes specified in NumberOfBytes param in one consecutive
 255   range.
 256
 257   @param[in]     VirtIo           The virtio device for which the mapping is
 258                                   requested.
 259
 260   @param[in]     Operation        Indicates if the bus master is going to
 261                                   read or write to system memory.
 262
 263   @param[in]     HostAddress      The system memory address to map to shared
 264                                   buffer address.
 265
 266   @param[in]     NumberOfBytes    Number of bytes to map.
 267
 268   @param[out]    DeviceAddress    The resulting shared map address for the
 269                                   bus master to access the hosts HostAddress.
 270
 271   @param[out]    Mapping          A resulting token to pass to
 272                                   VIRTIO_UNMAP_SHARED.
 273
 274
 275   @retval EFI_SUCCESS             The NumberOfBytes is succesfully mapped.
 276   @retval EFI_UNSUPPORTED         The HostAddress cannot be mapped as a
 277                                   common buffer.
 278   @retval EFI_INVALID_PARAMETER   One or more parameters are invalid.
 279   @retval EFI_OUT_OF_RESOURCES    The request could not be completed due to
 280                                   a lack of resources. This includes the case
 281                                   when NumberOfBytes bytes cannot be mapped
 282                                   in one consecutive range.
 283   @retval EFI_DEVICE_ERROR        The system hardware could not map the
 284                                   requested address.
 285 **/
 286 EFI_STATUS
 287 EFIAPI
 288 VirtioMapAllBytesInSharedBuffer (
 289   IN  VIRTIO_DEVICE_PROTOCOL  *VirtIo,
 290   IN  VIRTIO_MAP_OPERATION    Operation,
 291   IN  VOID                    *HostAddress,
 292   IN  UINTN                   NumberOfBytes,
 293   OUT EFI_PHYSICAL_ADDRESS    *DeviceAddress,
 294   OUT VOID                    **Mapping
 295   );
 296 #endif // _VIRTIO_LIB_H_