1 /* SPDX-License-Identifier: MIT */
3 * Details of the "wire" protocol between Xen Store Daemon and client
4 * library or guest kernel.
5 * Copyright (C) 2005 Rusty Russell IBM Corporation
14 #define XS_DEBUG XS_CONTROL
31 XS_IS_DOMAIN_INTRODUCED,
34 /* XS_RESTRICT has been removed */
35 XS_RESET_WATCHES = XS_SET_TARGET + 2,
38 XS_TYPE_COUNT, /* Number of valid types. */
40 XS_INVALID = 0xffff /* Guaranteed to remain an invalid type */
43 #define XS_WRITE_NONE "NONE"
44 #define XS_WRITE_CREATE "CREATE"
45 #define XS_WRITE_CREATE_EXCL "CREATE|EXCL"
47 /* We hand errors as strings, for portability. */
51 const char *errstring;
53 #define XSD_ERROR(x) { x, #x }
54 static struct xsd_errors xsd_errors[] __attribute__((unused)) = {
74 uint32_t type; /* XS_??? */
75 uint32_t req_id;/* Request identifier, echoed in daemon's response. */
76 uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */
77 uint32_t len; /* Length of data following this. */
79 /* Generally followed by nul-terminated string(s). */
88 /* Inter-domain shared memory communications. */
89 #define XENSTORE_RING_SIZE 1024
90 typedef uint32_t XENSTORE_RING_IDX;
91 #define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))
92 struct xenstore_domain_interface {
93 char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
94 char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
95 XENSTORE_RING_IDX req_cons, req_prod;
96 XENSTORE_RING_IDX rsp_cons, rsp_prod;
97 uint32_t server_features; /* Bitmap of features supported by the server */
102 /* Violating this is very bad. See docs/misc/xenstore.txt. */
103 #define XENSTORE_PAYLOAD_MAX 4096
105 /* Violating these just gets you an error back */
106 #define XENSTORE_ABS_PATH_MAX 3072
107 #define XENSTORE_REL_PATH_MAX 2048
109 /* The ability to reconnect a ring */
110 #define XENSTORE_SERVER_FEATURE_RECONNECTION 1
111 /* The presence of the "error" field in the ring page */
112 #define XENSTORE_SERVER_FEATURE_ERROR 2
114 /* Valid values for the connection field */
115 #define XENSTORE_CONNECTED 0 /* the steady-state */
116 #define XENSTORE_RECONNECT 1 /* guest has initiated a reconnect */
118 /* Valid values for the error field */
119 #define XENSTORE_ERROR_NONE 0 /* No error */
120 #define XENSTORE_ERROR_COMM 1 /* Communication problem */
121 #define XENSTORE_ERROR_RINGIDX 2 /* Invalid ring index */
122 #define XENSTORE_ERROR_PROTO 3 /* Protocol violation (payload too long) */
124 #endif /* _XS_WIRE_H */