OvmfPkg/Include/IndustryStandard/Virtio.h

   1 /** @file
   2
   3   Generic type and macro definitions corresponding to the virtio-0.9.5
   4   specification.
   5
   6   Copyright (C) 2012, Red Hat, Inc.
   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_H_
  19 #define _VIRTIO_H_
  20
  21 #include <Base.h>
  22
  23 //
  24 // VirtIo Subsystem Device IDs
  25 //
  26 #define VIRTIO_SUBSYSTEM_NETWORK_CARD       1
  27 #define VIRTIO_SUBSYSTEM_BLOCK_DEVICE       2
  28 #define VIRTIO_SUBSYSTEM_CONSOLE            3
  29 #define VIRTIO_SUBSYSTEM_ENTROPY_SOURCE     4
  30 #define VIRTIO_SUBSYSTEM_MEMORY_BALLOONING  5
  31 #define VIRTIO_SUBSYSTEM_IO_MEMORY          6
  32 #define VIRTIO_SUBSYSTEM_RPMSG              7
  33 #define VIRTIO_SUBSYSTEM_SCSI_HOST          8
  34 #define VIRTIO_SUBSYSTEM_9P_TRANSPORT       9
  35 #define VIRTIO_SUBSYSTEM_MAC80211_WLAN      10
  36
  37 //
  38 // Data in the communication area is defined as packed and accessed as
  39 // volatile.
  40 //
  41 // Some structures contain arrays with dynamically determined size. In such
  42 // cases the array and its sibling fields are replaced with pointers.
  43 //
  44 // All indices (variables and fields named *Idx) are free-running and wrap
  45 // around after 0xFFFF. The queue size reported by the host is always an
  46 // integral power of 2, not greater than 32768. Actual array indices are
  47 // consistently calculated by taking the remainder of a given Idx object modulo
  48 // QueueSize. Since 0x10000 is an integral multiple of the QueueSize, UINT16
  49 // wraparound is a correct wraparound modulo QueueSize too (it doesn't offset
  50 // the remainder class).
  51 //
  52 // virtio-0.9.5, 2.3.4 Available Ring
  53 //
  54 #define VRING_AVAIL_F_NO_INTERRUPT BIT0
  55
  56 typedef struct {
  57   volatile UINT16 *Flags;
  58   volatile UINT16 *Idx;
  59
  60   volatile UINT16 *Ring;      // QueueSize elements
  61   volatile UINT16 *UsedEvent; // unused as per negotiation
  62 } VRING_AVAIL;
  63
  64
  65 //
  66 // virtio-0.9.5, 2.3.5 Used Ring
  67 //
  68 #define VRING_USED_F_NO_NOTIFY BIT0
  69
  70 #pragma pack(1)
  71 typedef struct {
  72   UINT32 Id;
  73   UINT32 Len;
  74 } VRING_USED_ELEM;
  75 #pragma pack()
  76
  77 typedef struct {
  78   volatile UINT16          *Flags;
  79   volatile UINT16          *Idx;
  80   volatile VRING_USED_ELEM *UsedElem;   // QueueSize elements
  81   volatile UINT16          *AvailEvent; // unused as per negotiation
  82 } VRING_USED;
  83
  84
  85 //
  86 // virtio-0.9.5, 2.3.2 Descriptor Table
  87 //
  88 #define VRING_DESC_F_NEXT     BIT0 // more descriptors in this request
  89 #define VRING_DESC_F_WRITE    BIT1 // buffer to be written *by the host*
  90 #define VRING_DESC_F_INDIRECT BIT2 // unused
  91
  92 #pragma pack(1)
  93 typedef struct {
  94   UINT64 Addr;
  95   UINT32 Len;
  96   UINT16 Flags;
  97   UINT16 Next;
  98 } VRING_DESC;
  99 #pragma pack()
 100
 101 typedef struct {
 102   UINTN               NumPages;
 103   VOID                *Base;     // deallocate only this field
 104   volatile VRING_DESC *Desc;     // QueueSize elements
 105   VRING_AVAIL         Avail;
 106   VRING_USED          Used;
 107   UINT16              QueueSize;
 108 } VRING;
 109
 110
 111 //
 112 // virtio-0.9.5, 2.2.2 Virtio Header -- no MSI-X
 113 //
 114 #pragma pack(1)
 115 typedef struct {
 116   UINT32 VhdrDeviceFeatureBits;
 117   UINT32 VhdrGuestFeatureBits;
 118   UINT32 VhdrQueueAddress;
 119   UINT16 VhdrQueueSize;
 120   UINT16 VhdrQueueSelect;
 121   UINT16 VhdrQueueNotify;
 122   UINT8  VhdrDeviceStatus;
 123   UINT8  VhdrISR;
 124 } VIRTIO_HDR;
 125 #pragma pack()
 126
 127
 128 //
 129 // virtio-0.9.5, 2.2.2.1 Device Status
 130 //
 131 #define VSTAT_ACK       BIT0
 132 #define VSTAT_DRIVER    BIT1
 133 #define VSTAT_DRIVER_OK BIT2
 134 #define VSTAT_FAILED    BIT7
 135
 136 //
 137 // virtio-0.9.5, Appendix B: Reserved (Device-Independent) Feature Bits
 138 //
 139 #define VIRTIO_F_NOTIFY_ON_EMPTY    BIT24
 140 #define VIRTIO_F_RING_INDIRECT_DESC BIT28
 141 #define VIRTIO_F_RING_EVENT_IDX     BIT29
 142
 143
 144 #endif // _VIRTIO_H_