2 * An implementation of HyperV key value pair (KVP) functionality for Linux.
5 * Copyright (C) 2010, Novell, Inc.
6 * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 as published
10 * by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
15 * NON INFRINGEMENT. See the GNU General Public License for more
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
27 * Maximum value size - used for both key names and value data, and includes
28 * any applicable NULL terminators.
30 * Note: This limit is somewhat arbitrary, but falls easily within what is
31 * supported for all native guests (back to Win 2000) and what is reasonable
32 * for the IC KVP exchange functionality. Note that Windows Me/98/95 are
33 * limited to 255 character key names.
35 * MSDN recommends not storing data values larger than 2048 bytes in the
38 * Note: This value is used in defining the KVP exchange message - this value
39 * cannot be modified without affecting the message size and compatibility.
43 * bytes, including any null terminators
45 #define HV_KVP_EXCHANGE_MAX_VALUE_SIZE (2048)
49 * Maximum key size - the registry limit for the length of an entry name
50 * is 256 characters, including the null terminator
53 #define HV_KVP_EXCHANGE_MAX_KEY_SIZE (512)
56 * In Linux, we implement the KVP functionality in two components:
57 * 1) The kernel component which is packaged as part of the hv_utils driver
58 * is responsible for communicating with the host and responsible for
59 * implementing the host/guest protocol. 2) A user level daemon that is
60 * responsible for data gathering.
62 * Host/Guest Protocol: The host iterates over an index and expects the guest
63 * to assign a key name to the index and also return the value corresponding to
64 * the key. The host will have atmost one KVP transaction outstanding at any
65 * given point in time. The host side iteration stops when the guest returns
66 * an error. Microsoft has specified the following mapping of key names to
67 * host specified index:
70 * 0 FullyQualifiedDomainName
71 * 1 IntegrationServicesVersion
72 * 2 NetworkAddressIPv4
73 * 3 NetworkAddressIPv6
79 * 9 ProcessorArchitecture
81 * The Windows host expects the Key Name and Key Value to be encoded in utf16.
83 * Guest Kernel/KVP Daemon Protocol: As noted earlier, we implement all of the
84 * data gathering functionality in a user mode daemon. The user level daemon
85 * is also responsible for binding the key name to the index as well. The
86 * kernel and user-level daemon communicate using a connector channel.
88 * The user mode component first registers with the
89 * the kernel component. Subsequently, the kernel component requests, data
90 * for the specified keys. In response to this message the user mode component
91 * fills in the value corresponding to the specified key. We overload the
92 * sequence field in the cn_msg header to define our KVP message types.
95 * The kernel component simply acts as a conduit for communication between the
96 * Windows host and the user-level daemon. The kernel component passes up the
97 * index received from the Host to the user-level daemon. If the index is
98 * valid (supported), the corresponding key as well as its
99 * value (both are strings) is returned. If the index is invalid
100 * (not supported), a NULL key string is returned.
105 * The following definitions are shared with the user-mode component; do not
106 * change any of this without making the corresponding changes in
107 * the KVP user-mode component.
110 #define CN_KVP_VAL 0x1 /* This supports queries from the kernel */
111 #define CN_KVP_USER_VAL 0x2 /* This supports queries from the user */
114 KVP_REGISTER = 0, /* Register the user mode component */
115 KVP_KERNEL_GET, /* Kernel is requesting the value */
116 KVP_KERNEL_SET, /* Kernel is providing the value */
117 KVP_USER_GET, /* User is requesting the value */
118 KVP_USER_SET /* User is providing the value */
122 __u32 kvp_index; /* Key index */
123 __u8 kvp_key[HV_KVP_EXCHANGE_MAX_KEY_SIZE]; /* Key name */
124 __u8 kvp_value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE]; /* Key value */
133 * Registry value types.
138 enum hv_kvp_exchg_op {
143 KVP_OP_COUNT /* Number of operations, must be last. */
146 enum hv_kvp_exchg_pool {
147 KVP_POOL_EXTERNAL = 0,
150 KVP_POOL_AUTO_EXTERNAL,
151 KVP_POOL_AUTO_INTERNAL,
152 KVP_POOL_COUNT /* Number of pools, must be last. */
160 struct hv_kvp_exchg_msg_value {
164 u8 key[HV_KVP_EXCHANGE_MAX_KEY_SIZE];
165 u8 value[HV_KVP_EXCHANGE_MAX_VALUE_SIZE];
168 struct hv_kvp_msg_enumerate {
170 struct hv_kvp_exchg_msg_value data;
174 struct hv_kvp_hdr kvp_hdr;
175 struct hv_kvp_msg_enumerate kvp_data;
178 int hv_kvp_init(struct hv_util_service *);
179 void hv_kvp_deinit(void);
180 void hv_kvp_onchannelcallback(void *);
182 #endif /* __KERNEL__ */