OvmfPkg/Include/IndustryStandard/Xen/io/xs_wire.h

   1 /*
   2  * Details of the "wire" protocol between Xen Store Daemon and client
   3  * library or guest kernel.
   4  *
   5  * SPDX-License-Identifier: MIT
   6  *
   7  * Copyright (C) 2005 Rusty Russell IBM Corporation
   8  */
   9
  10 #ifndef _XS_WIRE_H
  11 #define _XS_WIRE_H
  12
  13 enum xsd_sockmsg_type {
  14   XS_DEBUG,
  15   XS_DIRECTORY,
  16   XS_READ,
  17   XS_GET_PERMS,
  18   XS_WATCH,
  19   XS_UNWATCH,
  20   XS_TRANSACTION_START,
  21   XS_TRANSACTION_END,
  22   XS_INTRODUCE,
  23   XS_RELEASE,
  24   XS_GET_DOMAIN_PATH,
  25   XS_WRITE,
  26   XS_MKDIR,
  27   XS_RM,
  28   XS_SET_PERMS,
  29   XS_WATCH_EVENT,
  30   XS_ERROR,
  31   XS_IS_DOMAIN_INTRODUCED,
  32   XS_RESUME,
  33   XS_SET_TARGET,
  34   XS_RESTRICT,
  35   XS_RESET_WATCHES,
  36
  37   XS_INVALID = 0xffff   /* Guaranteed to remain an invalid type */
  38 };
  39
  40 #define XS_WRITE_NONE         "NONE"
  41 #define XS_WRITE_CREATE       "CREATE"
  42 #define XS_WRITE_CREATE_EXCL  "CREATE|EXCL"
  43
  44 /* We hand errors as strings, for portability. */
  45 struct xsd_errors {
  46   INT32          errnum;
  47   const CHAR8    *errstring;
  48 };
  49
  50 #ifdef EINVAL
  51 #define XSD_ERROR(x)  { x, #x }
  52 /* LINTED: static unused */
  53 static struct xsd_errors xsd_errors[]
  54   #if defined (__GNUC__)
  55 __attribute__ ((unused))
  56   #endif
  57   = {
  58   XSD_ERROR (EINVAL),
  59   XSD_ERROR (EACCES),
  60   XSD_ERROR (EEXIST),
  61   XSD_ERROR (EISDIR),
  62   XSD_ERROR (ENOENT),
  63   XSD_ERROR (ENOMEM),
  64   XSD_ERROR (ENOSPC),
  65   XSD_ERROR (EIO),
  66   XSD_ERROR (ENOTEMPTY),
  67   XSD_ERROR (ENOSYS),
  68   XSD_ERROR (EROFS),
  69   XSD_ERROR (EBUSY),
  70   XSD_ERROR (EAGAIN),
  71   XSD_ERROR (EISCONN),
  72   XSD_ERROR (E2BIG)
  73   };
  74 #endif
  75
  76 struct xsd_sockmsg {
  77   UINT32    type;   /* XS_??? */
  78   UINT32    req_id; /* Request identifier, echoed in daemon's response.  */
  79   UINT32    tx_id;  /* Transaction id (0 if not related to a transaction). */
  80   UINT32    len;    /* Length of data following this. */
  81
  82   /* Generally followed by nul-terminated string(s). */
  83 };
  84
  85 enum xs_watch_type {
  86   XS_WATCH_PATH = 0,
  87   XS_WATCH_TOKEN
  88 };
  89
  90 /*
  91  * `incontents 150 xenstore_struct XenStore wire protocol.
  92  *
  93  * Inter-domain shared memory communications. */
  94 #define XENSTORE_RING_SIZE  1024
  95 typedef UINT32 XENSTORE_RING_IDX;
  96 #define MASK_XENSTORE_IDX(idx)  ((idx) & (XENSTORE_RING_SIZE-1))
  97 struct xenstore_domain_interface {
  98   CHAR8                req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
  99   CHAR8                rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
 100   XENSTORE_RING_IDX    req_cons, req_prod;
 101   XENSTORE_RING_IDX    rsp_cons, rsp_prod;
 102   UINT32               server_features; /* Bitmap of features supported by the server */
 103   UINT32               connection;
 104 };
 105
 106 /* Violating this is very bad.  See docs/misc/xenstore.txt. */
 107 #define XENSTORE_PAYLOAD_MAX  4096
 108
 109 /* Violating these just gets you an error back */
 110 #define XENSTORE_ABS_PATH_MAX  3072
 111 #define XENSTORE_REL_PATH_MAX  2048
 112
 113 /* The ability to reconnect a ring */
 114 #define XENSTORE_SERVER_FEATURE_RECONNECTION  1
 115
 116 /* Valid values for the connection field */
 117 #define XENSTORE_CONNECTED  0 /* the steady-state */
 118 #define XENSTORE_RECONNECT  1 /* guest has initiated a reconnect */
 119
 120 #endif /* _XS_WIRE_H */
 121
 122 /*
 123  * Local variables:
 124  * mode: C
 125  * c-file-style: "BSD"
 126  * c-basic-offset: 4
 127  * tab-width: 4
 128  * indent-tabs-mode: nil
 129  * End:
 130  */