1 files changed, 131 insertions, 0 deletions
diff --git a/edk2/OvmfPkg/Include/IndustryStandard/Virtio.h b/edk2/OvmfPkg/Include/IndustryStandard/Virtio.h
new file mode 100644
index 000000000..05c658fa5
--- /dev/null
+++ b/edk2/OvmfPkg/Include/IndustryStandard/Virtio.h
@@ -0,0 +1,131 @@
+/** @file
+
+  Generic type and macro definitions corresponding to the virtio-0.9.5
+  specification.
+
+  Copyright (C) 2012, Red Hat, Inc.
+
+  This program and the accompanying materials are licensed and made available
+  under the terms and conditions of the BSD License which accompanies this
+  distribution. The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#ifndef _VIRTIO_H_
+#define _VIRTIO_H_
+
+#include <Base.h>
+
+
+//
+// Data in the communication area is defined as packed and accessed as
+// volatile.
+//
+// Some structures contain arrays with dynamically determined size. In such
+// cases the array and its sibling fields are replaced with pointers.
+//
+// All indices (variables and fields named *Idx) are free-running and wrap
+// around after 0xFFFF. The queue size reported by the host is always an
+// integral power of 2, not greater than 32768. Actual array indices are
+// consistently calculated by taking the remainder of a given Idx object modulo
+// QueueSize. Since 0x10000 is an integral multiple of the QueueSize, UINT16
+// wraparound is a correct wraparound modulo QueueSize too (it doesn't offset
+// the remainder class).
+//
+// virtio-0.9.5, 2.3.4 Available Ring
+//
+#define VRING_AVAIL_F_NO_INTERRUPT BIT0
+
+typedef struct {
+  volatile UINT16 *Flags;
+  volatile UINT16 *Idx;
+
+  volatile UINT16 *Ring;      // QueueSize elements
+  volatile UINT16 *UsedEvent; // unused as per negotiation
+} VRING_AVAIL;
+
+
+//
+// virtio-0.9.5, 2.3.5 Used Ring
+//
+#define VRING_USED_F_NO_NOTIFY BIT0
+
+#pragma pack(1)
+typedef struct {
+  UINT32 Id;
+  UINT32 Len;
+} VRING_USED_ELEM;
+#pragma pack()
+
+typedef struct {
+  volatile UINT16          *Flags;
+  volatile UINT16          *Idx;
+  volatile VRING_USED_ELEM *UsedElem;   // QueueSize elements
+  volatile UINT16          *AvailEvent; // unused as per negotiation
+} VRING_USED;
+
+
+//
+// virtio-0.9.5, 2.3.2 Descriptor Table
+//
+#define VRING_DESC_F_NEXT     BIT0 // more descriptors in this request
+#define VRING_DESC_F_WRITE    BIT1 // buffer to be written *by the host*
+#define VRING_DESC_F_INDIRECT BIT2 // unused
+
+#pragma pack(1)
+typedef struct {
+  UINT64 Addr;
+  UINT32 Len;
+  UINT16 Flags;
+  UINT16 Next;
+} VRING_DESC;
+#pragma pack()
+
+typedef struct {
+  UINTN               NumPages;
+  VOID                *Base;     // deallocate only this field
+  volatile VRING_DESC *Desc;     // QueueSize elements
+  VRING_AVAIL         Avail;
+  VRING_USED          Used;
+  UINT16              QueueSize;
+} VRING;
+
+
+//
+// virtio-0.9.5, 2.2.2 Virtio Header -- no MSI-X
+//
+#pragma pack(1)
+typedef struct {
+  UINT32 VhdrDeviceFeatureBits;
+  UINT32 VhdrGuestFeatureBits;
+  UINT32 VhdrQueueAddress;
+  UINT16 VhdrQueueSize;
+  UINT16 VhdrQueueSelect;
+  UINT16 VhdrQueueNotify;
+  UINT8  VhdrDeviceStatus;
+  UINT8  VhdrISR;
+} VIRTIO_HDR;
+#pragma pack()
+
+
+//
+// virtio-0.9.5, 2.2.2.1 Device Status
+//
+#define VSTAT_ACK       BIT0
+#define VSTAT_DRIVER    BIT1
+#define VSTAT_DRIVER_OK BIT2
+#define VSTAT_FAILED    BIT7
+
+//
+// virtio-0.9.5, Appendix B: Reserved (Device-Independent) Feature Bits
+//
+#define VIRTIO_F_NOTIFY_ON_EMPTY    BIT24
+#define VIRTIO_F_RING_INDIRECT_DESC BIT28
+#define VIRTIO_F_RING_EVENT_IDX     BIT29
+
+
+#endif // _VIRTIO_H_