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   Portion of Copyright (C) 2013, ARM Ltd.
   8
   9   This program and the accompanying materials are licensed and made available
  10   under the terms and conditions of the BSD License which accompanies this
  11   distribution. The full text of the license may be found at
  12   http://opensource.org/licenses/bsd-license.php
  13
  14   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
  15   WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  16
  17 **/
  18
  19 #ifndef _VIRTIO_H_
  20 #define _VIRTIO_H_
  21
  22 #include <Base.h>
  23
  24 //
  25 // VirtIo Subsystem Device IDs
  26 //
  27 #define VIRTIO_SUBSYSTEM_NETWORK_CARD       1
  28 #define VIRTIO_SUBSYSTEM_BLOCK_DEVICE       2
  29 #define VIRTIO_SUBSYSTEM_CONSOLE            3
  30 #define VIRTIO_SUBSYSTEM_ENTROPY_SOURCE     4
  31 #define VIRTIO_SUBSYSTEM_MEMORY_BALLOONING  5
  32 #define VIRTIO_SUBSYSTEM_IO_MEMORY          6
  33 #define VIRTIO_SUBSYSTEM_RPMSG              7
  34 #define VIRTIO_SUBSYSTEM_SCSI_HOST          8
  35 #define VIRTIO_SUBSYSTEM_9P_TRANSPORT       9
  36 #define VIRTIO_SUBSYSTEM_MAC80211_WLAN      10
  37
  38 //
  39 // VirtIo Device Specific Configuration Offsets
  40 //
  41 #define VIRTIO_DEVICE_SPECIFIC_CONFIGURATION_OFFSET_PCI             20
  42 #define VIRTIO_DEVICE_SPECIFIC_CONFIGURATION_OFFSET_PCI_WITH_MSI_X  24
  43 #define VIRTIO_DEVICE_SPECIFIC_CONFIGURATION_OFFSET_MMIO            0x100
  44
  45 //
  46 // PCI VirtIo Header Offsets
  47 //
  48 #define VIRTIO_PCI_OFFSET_DEVICE_FEATURES           0x00
  49 #define VIRTIO_PCI_OFFSET_GUEST_FEATURES            0x04
  50 #define VIRTIO_PCI_OFFSET_QUEUE_ADDRESS             0x08
  51 #define VIRTIO_PCI_OFFSET_QUEUE_SIZE                0x0C
  52 #define VIRTIO_PCI_OFFSET_QUEUE_SELECT              0x0E
  53 #define VIRTIO_PCI_OFFSET_QUEUE_NOTIFY              0x10
  54 #define VIRTIO_PCI_OFFSET_QUEUE_DEVICE_STATUS       0x12
  55 #define VIRTIO_PCI_OFFSET_QUEUE_DEVICE_ISR          0x13
  56
  57 //
  58 // MMIO VirtIo Header Offsets
  59 //
  60 #define VIRTIO_MMIO_OFFSET_MAGIC                    0x00
  61 #define VIRTIO_MMIO_OFFSET_VERSION                  0x04
  62 #define VIRTIO_MMIO_OFFSET_DEVICE_ID                0x08
  63 #define VIRTIO_MMIO_OFFSET_VENDOR_ID                0x0C
  64 #define VIRTIO_MMIO_OFFSET_HOST_FEATURES            0x10
  65 #define VIRTIO_MMIO_OFFSET_HOST_FEATURES_SEL        0x14
  66 #define VIRTIO_MMIO_OFFSET_GUEST_FEATURES           0x20
  67 #define VIRTIO_MMIO_OFFSET_GUEST_FEATURES_SEL       0x24
  68 #define VIRTIO_MMIO_OFFSET_GUEST_PAGE_SIZE          0x28
  69 #define VIRTIO_MMIO_OFFSET_QUEUE_SEL                0x30
  70 #define VIRTIO_MMIO_OFFSET_QUEUE_NUM_MAX            0x34
  71 #define VIRTIO_MMIO_OFFSET_QUEUE_NUM                0x38
  72 #define VIRTIO_MMIO_OFFSET_QUEUE_ALIGN              0x3C
  73 #define VIRTIO_MMIO_OFFSET_QUEUE_PFN                0x40
  74 #define VIRTIO_MMIO_OFFSET_QUEUE_NOTIFY             0x50
  75 #define VIRTIO_MMIO_OFFSET_INTERRUPT_STATUS         0x60
  76 #define VIRTIO_MMIO_OFFSET_INTERRUPT_ACK            0x64
  77 #define VIRTIO_MMIO_OFFSET_STATUS                   0x70
  78
  79 //
  80 // Data in the communication area is defined as packed and accessed as
  81 // volatile.
  82 //
  83 // Some structures contain arrays with dynamically determined size. In such
  84 // cases the array and its sibling fields are replaced with pointers.
  85 //
  86 // All indices (variables and fields named *Idx) are free-running and wrap
  87 // around after 0xFFFF. The queue size reported by the host is always an
  88 // integral power of 2, not greater than 32768. Actual array indices are
  89 // consistently calculated by taking the remainder of a given Idx object modulo
  90 // QueueSize. Since 0x10000 is an integral multiple of the QueueSize, UINT16
  91 // wraparound is a correct wraparound modulo QueueSize too (it doesn't offset
  92 // the remainder class).
  93 //
  94 // virtio-0.9.5, 2.3.4 Available Ring
  95 //
  96 #define VRING_AVAIL_F_NO_INTERRUPT BIT0
  97
  98 typedef struct {
  99   volatile UINT16 *Flags;
 100   volatile UINT16 *Idx;
 101
 102   volatile UINT16 *Ring;      // QueueSize elements
 103   volatile UINT16 *UsedEvent; // unused as per negotiation
 104 } VRING_AVAIL;
 105
 106
 107 //
 108 // virtio-0.9.5, 2.3.5 Used Ring
 109 //
 110 #define VRING_USED_F_NO_NOTIFY BIT0
 111
 112 #pragma pack(1)
 113 typedef struct {
 114   UINT32 Id;
 115   UINT32 Len;
 116 } VRING_USED_ELEM;
 117 #pragma pack()
 118
 119 typedef struct {
 120   volatile UINT16          *Flags;
 121   volatile UINT16          *Idx;
 122   volatile VRING_USED_ELEM *UsedElem;   // QueueSize elements
 123   volatile UINT16          *AvailEvent; // unused as per negotiation
 124 } VRING_USED;
 125
 126
 127 //
 128 // virtio-0.9.5, 2.3.2 Descriptor Table
 129 //
 130 #define VRING_DESC_F_NEXT     BIT0 // more descriptors in this request
 131 #define VRING_DESC_F_WRITE    BIT1 // buffer to be written *by the host*
 132 #define VRING_DESC_F_INDIRECT BIT2 // unused
 133
 134 #pragma pack(1)
 135 typedef struct {
 136   UINT64 Addr;
 137   UINT32 Len;
 138   UINT16 Flags;
 139   UINT16 Next;
 140 } VRING_DESC;
 141 #pragma pack()
 142
 143 typedef struct {
 144   UINTN               NumPages;
 145   VOID                *Base;     // deallocate only this field
 146   volatile VRING_DESC *Desc;     // QueueSize elements
 147   VRING_AVAIL         Avail;
 148   VRING_USED          Used;
 149   UINT16              QueueSize;
 150 } VRING;
 151
 152
 153 //
 154 // virtio-0.9.5, 2.2.2 Virtio Header -- no MSI-X
 155 //
 156 #pragma pack(1)
 157 typedef struct {
 158   UINT32 VhdrDeviceFeatureBits;
 159   UINT32 VhdrGuestFeatureBits;
 160   UINT32 VhdrQueueAddress;
 161   UINT16 VhdrQueueSize;
 162   UINT16 VhdrQueueSelect;
 163   UINT16 VhdrQueueNotify;
 164   UINT8  VhdrDeviceStatus;
 165   UINT8  VhdrISR;
 166 } VIRTIO_HDR;
 167 #pragma pack()
 168
 169
 170 //
 171 // virtio-0.9.5, 2.2.2.1 Device Status
 172 //
 173 #define VSTAT_ACK       BIT0
 174 #define VSTAT_DRIVER    BIT1
 175 #define VSTAT_DRIVER_OK BIT2
 176 #define VSTAT_FAILED    BIT7
 177
 178 //
 179 // virtio-0.9.5, Appendix B: Reserved (Device-Independent) Feature Bits
 180 //
 181 #define VIRTIO_F_NOTIFY_ON_EMPTY    BIT24
 182 #define VIRTIO_F_RING_INDIRECT_DESC BIT28
 183 #define VIRTIO_F_RING_EVENT_IDX     BIT29
 184
 185
 186 #endif // _VIRTIO_H_