OvmfPkg: Introduce XenBus Protocol.

This protocol will be used for communication between a PV driver (like a
PV block driver) and the XenBus/XenStore.

Change in V5:
- Replace the license by the commonly used file header text.

Change in V3:
- Add disclaimer about the volatile nature of the protocol.
- Add a description on the two introduced members to the protocol.

Change in V2:
- Comment, file header
- Protocol License
- Declare xen interface version earlier
- Rename protocol from Xenbus to XenBus

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16262 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 92 insertions, 0 deletions

diff --git a/OvmfPkg/Include/Protocol/XenBus.h b/OvmfPkg/Include/Protocol/XenBus.h
new file mode 100644
index 0000000000..89bf74fbc5
--- /dev/null
+++ b/OvmfPkg/Include/Protocol/XenBus.h
@@ -0,0 +1,92 @@
+

+/** @file

+  XenBus protocol to be used between the XenBus bus driver and Xen PV devices.

+

+  DISCLAIMER: the XENBUS_PROTOCOL introduced here is a work in progress, and

+  should not be used outside of the EDK II tree.

+

+  This protocol provide the necessary for a Xen PV driver frontend to

+  communicate with the bus driver, and perform several task to

+  initialize/shutdown a PV device and perform IO with a PV backend.

+

+  Copyright (C) 2014, Citrix Ltd.

+

+  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 __PROTOCOL_XENBUS_H__

+#define __PROTOCOL_XENBUS_H__

+

+#define XENBUS_PROTOCOL_GUID \

+  {0x3d3ca290, 0xb9a5, 0x11e3, {0xb7, 0x5d, 0xb8, 0xac, 0x6f, 0x7d, 0x65, 0xe6}}

+

+///

+/// Forward declaration

+///

+typedef struct _XENBUS_PROTOCOL XENBUS_PROTOCOL;

+

+

+#include <IndustryStandard/Xen/grant_table.h>

+

+///

+/// Function prototypes

+///

+

+/**

+  Grant access to the page Frame to the domain DomainId.

+

+  @param This       A pointer to XENBUS_PROTOCOL instance.

+  @param DomainId   ID of the domain to grant acces to.

+  @param Frame      Frame Number of the page to grant access to.

+  @param ReadOnly   Provide read-only or read-write access.

+  @param RefPtr     Reference number of the grant will be writen to this pointer.

+**/

+typedef

+EFI_STATUS

+(EFIAPI *XENBUS_GRANT_ACCESS)(

+  IN  XENBUS_PROTOCOL *This,

+  IN  domid_t         DomainId,

+  IN  UINTN           Frame,

+  IN  BOOLEAN         ReadOnly,

+  OUT grant_ref_t     *refp

+  );

+

+/**

+  End access to grant Ref, previously return by XenBusGrantAccess.

+

+  @param This       A pointer to XENBUS_PROTOCOL instance.

+  @param Ref        Reference numeber of a grant previously returned by

+                    XenBusGrantAccess.

+**/

+typedef

+EFI_STATUS

+(EFIAPI *XENBUS_GRANT_END_ACCESS)(

+  IN XENBUS_PROTOCOL  *This,

+  IN grant_ref_t      Ref

+  );

+

+

+///

+/// Protocol structure

+///

+/// DISCLAIMER: the XENBUS_PROTOCOL introduced here is a work in progress, and

+/// should not be used outside of the EDK II tree.

+///

+struct _XENBUS_PROTOCOL {

+  XENBUS_GRANT_ACCESS           GrantAccess;

+  XENBUS_GRANT_END_ACCESS       GrantEndAccess;

+  //

+  // Protocol data fields

+  //

+};

+

+extern EFI_GUID gXenBusProtocolGuid;

+

+#endif