audk/OvmfPkg/Include/Protocol/XenBus.h

411 lines
12 KiB
C

/** @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.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#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;
typedef enum xenbus_state XenBusState;
typedef struct
{
UINT32 Id;
} XENSTORE_TRANSACTION;
#define XST_NIL ((XENSTORE_TRANSACTION *) NULL)
typedef enum {
XENSTORE_STATUS_SUCCESS = 0,
XENSTORE_STATUS_FAIL,
XENSTORE_STATUS_EINVAL,
XENSTORE_STATUS_EACCES,
XENSTORE_STATUS_EEXIST,
XENSTORE_STATUS_EISDIR,
XENSTORE_STATUS_ENOENT,
XENSTORE_STATUS_ENOMEM,
XENSTORE_STATUS_ENOSPC,
XENSTORE_STATUS_EIO,
XENSTORE_STATUS_ENOTEMPTY,
XENSTORE_STATUS_ENOSYS,
XENSTORE_STATUS_EROFS,
XENSTORE_STATUS_EBUSY,
XENSTORE_STATUS_EAGAIN,
XENSTORE_STATUS_EISCONN,
XENSTORE_STATUS_E2BIG
} XENSTORE_STATUS;
#include <IndustryStandard/Xen/grant_table.h>
#include <IndustryStandard/Xen/event_channel.h>
///
/// Function prototypes
///
/**
Get the contents of the node Node of the PV device. Returns the contents in
*Result which should be freed after use.
@param This A pointer to XENBUS_PROTOCOL instance.
@param Transaction The XenStore transaction covering this request.
@param Node The basename of the file to read.
@param Result The returned contents from this file.
@return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
indicating the type of failure.
@note The results buffer is malloced and should be free'd by the
caller.
**/
typedef
XENSTORE_STATUS
(EFIAPI *XENBUS_XS_READ)(
IN XENBUS_PROTOCOL *This,
IN CONST XENSTORE_TRANSACTION *Transaction,
IN CONST CHAR8 *Node,
OUT VOID **Result
);
/**
Get the contents of the node Node of the PV device's backend. Returns the
contents in *Result which should be freed after use.
@param This A pointer to XENBUS_PROTOCOL instance.
@param Transaction The XenStore transaction covering this request.
@param Node The basename of the file to read.
@param Result The returned contents from this file.
@return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
indicating the type of failure.
@note The results buffer is malloced and should be free'd by the
caller.
**/
typedef
XENSTORE_STATUS
(EFIAPI *XENBUS_XS_BACKEND_READ)(
IN XENBUS_PROTOCOL *This,
IN CONST XENSTORE_TRANSACTION *Transaction,
IN CONST CHAR8 *Node,
OUT VOID **Result
);
/**
Print formatted write to a XenStore node.
@param This A pointer to XENBUS_PROTOCOL instance.
@param Transaction The XenStore transaction covering this request.
@param Directory The dirname of the path to read.
@param Node The basename of the path to read.
@param Format AsciiSPrint format string followed by a variable number
of arguments.
@return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
indicating the type of write failure.
**/
typedef
XENSTORE_STATUS
(EFIAPI *XENBUS_XS_PRINTF) (
IN XENBUS_PROTOCOL *This,
IN CONST XENSTORE_TRANSACTION *Transaction,
IN CONST CHAR8 *Directory,
IN CONST CHAR8 *Node,
IN CONST CHAR8 *Format,
...
);
/**
Remove a node or directory (directories must be empty) of the PV driver's
subdirectory.
@param This A pointer to XENBUS_PROTOCOL instance.
@param Transaction The XenStore transaction covering this request.
@param Node The basename of the node to remove.
@return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
indicating the type of failure.
**/
typedef
XENSTORE_STATUS
(EFIAPI *XENBUS_XS_REMOVE) (
IN XENBUS_PROTOCOL *This,
IN CONST XENSTORE_TRANSACTION *Transaction,
IN CONST CHAR8 *Node
);
/**
Start a transaction.
Changes by others will not be seen during the lifetime of this
transaction, and changes will not be visible to others until it
is committed (XsTransactionEnd).
@param This A pointer to XENBUS_PROTOCOL instance.
@param Transaction The returned transaction.
@return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
indicating the type of failure.
**/
typedef
XENSTORE_STATUS
(EFIAPI *XENBUS_XS_TRANSACTION_START)(
IN XENBUS_PROTOCOL *This,
OUT XENSTORE_TRANSACTION *Transaction
);
/**
End a transaction.
@param This A pointer to XENBUS_PROTOCOL instance.
@param Transaction The transaction to end/commit.
@param Abort If TRUE, the transaction is discarded
instead of committed.
@return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
indicating the type of failure.
**/
typedef
XENSTORE_STATUS
(EFIAPI *XENBUS_XS_TRANSACTION_END) (
IN XENBUS_PROTOCOL *This,
IN CONST XENSTORE_TRANSACTION *Transaction,
IN BOOLEAN Abort
);
/**
Set a new state for the frontend of the PV driver.
@param This A pointer to XENBUS_PROTOCOL instance.
@param Transaction The transaction to end/commit.
@param State The new state to apply.
@return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
indicating the type of failure.
**/
typedef
XENSTORE_STATUS
(EFIAPI *XENBUS_SET_STATE)(
IN XENBUS_PROTOCOL *This,
IN CONST XENSTORE_TRANSACTION *Transaction,
IN XenBusState State
);
/**
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 written 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
);
/**
Allocate a port that can be bind from domain DomainId.
@param This A pointer to the XENBUS_PROTOCOL.
@param DomainId The domain ID that can bind the newly allocated port.
@param Port A pointer to a evtchn_port_t that will contain the newly
allocated port.
@retval UINT32 The return value from the hypercall, 0 if success.
**/
typedef
UINT32
(EFIAPI *XENBUS_EVENT_CHANNEL_ALLOCATE) (
IN XENBUS_PROTOCOL *This,
IN domid_t DomainId,
OUT evtchn_port_t *Port
);
/**
Send an event to the remote end of the channel whose local endpoint is Port.
@param This A pointer to the XENBUS_PROTOCOL.
@param Port Local port to the the event from.
@retval UINT32 The return value from the hypercall, 0 if success.
**/
typedef
UINT32
(EFIAPI *XENBUS_EVENT_CHANNEL_NOTIFY) (
IN XENBUS_PROTOCOL *This,
IN evtchn_port_t Port
);
/**
Close a local event channel Port.
@param This A pointer to the XENBUS_PROTOCOL.
@param Port The event channel to close.
@retval UINT32 The return value from the hypercall, 0 if success.
**/
typedef
UINT32
(EFIAPI *XENBUS_EVENT_CHANNEL_CLOSE) (
IN XENBUS_PROTOCOL *This,
IN evtchn_port_t Port
);
/**
Register a XenStore watch.
XenStore watches allow a client to wait for changes to an object in the
XenStore.
@param This A pointer to the XENBUS_PROTOCOL.
@param Node The basename of the path to watch.
@param Token A token.
@return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
indicating the type of write failure. EEXIST errors from the
XenStore are suppressed, allowing multiple, physically different,
xenbus_watch objects, to watch the same path in the XenStore.
**/
typedef
XENSTORE_STATUS
(EFIAPI *XENBUS_REGISTER_WATCH) (
IN XENBUS_PROTOCOL *This,
IN CONST CHAR8 *Node,
OUT VOID **Token
);
/**
Register a XenStore watch on a backend's node.
XenStore watches allow a client to wait for changes to an object in the
XenStore.
@param This A pointer to the XENBUS_PROTOCOL.
@param Node The basename of the path to watch.
@param Token A token.
@return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
indicating the type of write failure. EEXIST errors from the
XenStore are suppressed, allowing multiple, physically different,
xenbus_watch objects, to watch the same path in the XenStore.
**/
typedef
XENSTORE_STATUS
(EFIAPI *XENBUS_REGISTER_WATCH_BACKEND) (
IN XENBUS_PROTOCOL *This,
IN CONST CHAR8 *Node,
OUT VOID **Token
);
/**
Unregister a XenStore watch.
@param This A pointer to the XENBUS_PROTOCOL.
@param Token An token previously returned by a successful
call to RegisterWatch ().
**/
typedef
VOID
(EFIAPI *XENBUS_UNREGISTER_WATCH) (
IN XENBUS_PROTOCOL *This,
IN VOID *Token
);
/**
Block until the node watch by Token change.
@param This A pointer to the XENBUS_PROTOCOL.
@param Token An token previously returned by a successful
call to RegisterWatch or RegisterWatchBackend.
@return On success, XENSTORE_STATUS_SUCCESS. Otherwise an errno value
indicating the type of failure.
**/
typedef
XENSTORE_STATUS
(EFIAPI *XENBUS_WAIT_FOR_WATCH) (
IN XENBUS_PROTOCOL *This,
IN VOID *Token
);
///
/// 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_XS_READ XsRead;
XENBUS_XS_BACKEND_READ XsBackendRead;
XENBUS_XS_PRINTF XsPrintf;
XENBUS_XS_REMOVE XsRemove;
XENBUS_XS_TRANSACTION_START XsTransactionStart;
XENBUS_XS_TRANSACTION_END XsTransactionEnd;
XENBUS_SET_STATE SetState;
XENBUS_GRANT_ACCESS GrantAccess;
XENBUS_GRANT_END_ACCESS GrantEndAccess;
XENBUS_EVENT_CHANNEL_ALLOCATE EventChannelAllocate;
XENBUS_EVENT_CHANNEL_NOTIFY EventChannelNotify;
XENBUS_EVENT_CHANNEL_CLOSE EventChannelClose;
XENBUS_REGISTER_WATCH RegisterWatch;
XENBUS_REGISTER_WATCH_BACKEND RegisterWatchBackend;
XENBUS_UNREGISTER_WATCH UnregisterWatch;
XENBUS_WAIT_FOR_WATCH WaitForWatch;
//
// Protocol data fields
//
CONST CHAR8 *Type;
UINT16 DeviceId;
CONST CHAR8 *Node;
CONST CHAR8 *Backend;
};
extern EFI_GUID gXenBusProtocolGuid;
#endif