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a75eb03b DM |
1 | /* |
2 | * Copyright 6WIND S.A., 2014 | |
3 | * | |
4 | * This work is licensed under the terms of the GNU GPL, version 2 or | |
5 | * (at your option) any later version. See the COPYING file in the | |
6 | * top-level directory. | |
7 | */ | |
8 | ||
2a6a4076 MA |
9 | #ifndef IVSHMEM_SERVER_H |
10 | #define IVSHMEM_SERVER_H | |
a75eb03b DM |
11 | |
12 | /** | |
13 | * The ivshmem server is a daemon that creates a unix socket in listen | |
14 | * mode. The ivshmem clients (qemu or ivshmem-client) connect to this | |
15 | * unix socket. For each client, the server will create some eventfd | |
16 | * (see EVENTFD(2)), one per vector. These fd are transmitted to all | |
17 | * clients using the SCM_RIGHTS cmsg message. Therefore, each client is | |
cb8d4c8f | 18 | * able to send a notification to another client without being |
a75eb03b DM |
19 | * "profixied" by the server. |
20 | * | |
21 | * We use this mechanism to send interruptions between guests. | |
22 | * qemu is able to transform an event on a eventfd into a PCI MSI-x | |
23 | * interruption in the guest. | |
24 | * | |
25 | * The ivshmem server is also able to share the file descriptor | |
26 | * associated to the ivshmem shared memory. | |
27 | */ | |
28 | ||
a75eb03b | 29 | #include <sys/select.h> |
a75eb03b DM |
30 | |
31 | #include "qemu/event_notifier.h" | |
32 | #include "qemu/queue.h" | |
5105b1d8 | 33 | #include "hw/misc/ivshmem.h" |
a75eb03b DM |
34 | |
35 | /** | |
36 | * Maximum number of notification vectors supported by the server | |
37 | */ | |
38 | #define IVSHMEM_SERVER_MAX_VECTORS 64 | |
39 | ||
40 | /** | |
41 | * Structure storing a peer | |
42 | * | |
43 | * Each time a client connects to an ivshmem server, a new | |
44 | * IvshmemServerPeer structure is created. This peer and all its | |
45 | * vectors are advertised to all connected clients through the connected | |
46 | * unix sockets. | |
47 | */ | |
48 | typedef struct IvshmemServerPeer { | |
49 | QTAILQ_ENTRY(IvshmemServerPeer) next; /**< next in list*/ | |
50 | int sock_fd; /**< connected unix sock */ | |
f7a199b2 | 51 | int64_t id; /**< the id of the peer */ |
a75eb03b DM |
52 | EventNotifier vectors[IVSHMEM_SERVER_MAX_VECTORS]; /**< one per vector */ |
53 | unsigned vectors_count; /**< number of vectors */ | |
54 | } IvshmemServerPeer; | |
a75eb03b DM |
55 | |
56 | /** | |
57 | * Structure describing an ivshmem server | |
58 | * | |
59 | * This structure stores all information related to our server: the name | |
60 | * of the server unix socket and the list of connected peers. | |
61 | */ | |
62 | typedef struct IvshmemServer { | |
63 | char unix_sock_path[PATH_MAX]; /**< path to unix socket */ | |
64 | int sock_fd; /**< unix sock file descriptor */ | |
65 | char shm_path[PATH_MAX]; /**< path to shm */ | |
3625c739 | 66 | bool use_shm_open; |
a75eb03b DM |
67 | size_t shm_size; /**< size of shm */ |
68 | int shm_fd; /**< shm file descriptor */ | |
69 | unsigned n_vectors; /**< number of vectors */ | |
022cffe3 | 70 | uint16_t cur_id; /**< id to be given to next client */ |
a75eb03b | 71 | bool verbose; /**< true in verbose mode */ |
b58deb34 | 72 | QTAILQ_HEAD(, IvshmemServerPeer) peer_list; /**< list of peers */ |
a75eb03b DM |
73 | } IvshmemServer; |
74 | ||
75 | /** | |
76 | * Initialize an ivshmem server | |
77 | * | |
78 | * @server: A pointer to an uninitialized IvshmemServer structure | |
79 | * @unix_sock_path: The pointer to the unix socket file name | |
80 | * @shm_path: Path to the shared memory. The path corresponds to a POSIX | |
1e21feb6 | 81 | * shm name or a hugetlbfs mount point. |
a75eb03b DM |
82 | * @shm_size: Size of shared memory |
83 | * @n_vectors: Number of interrupt vectors per client | |
84 | * @verbose: True to enable verbose mode | |
85 | * | |
86 | * Returns: 0 on success, or a negative value on error | |
87 | */ | |
88 | int | |
89 | ivshmem_server_init(IvshmemServer *server, const char *unix_sock_path, | |
3625c739 MA |
90 | const char *shm_path, bool use_shm_open, |
91 | size_t shm_size, unsigned n_vectors, | |
a75eb03b DM |
92 | bool verbose); |
93 | ||
94 | /** | |
95 | * Open the shm, then create and bind to the unix socket | |
96 | * | |
97 | * @server: The pointer to the initialized IvshmemServer structure | |
98 | * | |
99 | * Returns: 0 on success, or a negative value on error | |
100 | */ | |
101 | int ivshmem_server_start(IvshmemServer *server); | |
102 | ||
103 | /** | |
104 | * Close the server | |
105 | * | |
106 | * Close connections to all clients, close the unix socket and the | |
107 | * shared memory file descriptor. The structure remains initialized, so | |
108 | * it is possible to call ivshmem_server_start() again after a call to | |
109 | * ivshmem_server_close(). | |
110 | * | |
111 | * @server: The ivshmem server | |
112 | */ | |
113 | void ivshmem_server_close(IvshmemServer *server); | |
114 | ||
115 | /** | |
116 | * Fill a fd_set with file descriptors to be monitored | |
117 | * | |
118 | * This function will fill a fd_set with all file descriptors that must | |
119 | * be polled (unix server socket and peers unix socket). The function | |
120 | * will not initialize the fd_set, it is up to the caller to do it. | |
121 | * | |
122 | * @server: The ivshmem server | |
123 | * @fds: The fd_set to be updated | |
124 | * @maxfd: Must be set to the max file descriptor + 1 in fd_set. This value is | |
125 | * updated if this function adds a greater fd in fd_set. | |
126 | */ | |
127 | void | |
128 | ivshmem_server_get_fds(const IvshmemServer *server, fd_set *fds, int *maxfd); | |
129 | ||
130 | /** | |
131 | * Read and handle new messages | |
132 | * | |
133 | * Given a fd_set (for instance filled by a call to select()), handle | |
134 | * incoming messages from peers. | |
135 | * | |
136 | * @server: The ivshmem server | |
137 | * @fds: The fd_set containing the file descriptors to be checked. Note that | |
138 | * file descriptors that are not related to our server are ignored. | |
139 | * @maxfd: The maximum fd in fd_set, plus one. | |
140 | * | |
141 | * Returns: 0 on success, or a negative value on error | |
142 | */ | |
143 | int ivshmem_server_handle_fds(IvshmemServer *server, fd_set *fds, int maxfd); | |
144 | ||
145 | /** | |
146 | * Search a peer from its identifier | |
147 | * | |
148 | * @server: The ivshmem server | |
149 | * @peer_id: The identifier of the peer structure | |
150 | * | |
151 | * Returns: The peer structure, or NULL if not found | |
152 | */ | |
153 | IvshmemServerPeer * | |
f7a199b2 | 154 | ivshmem_server_search_peer(IvshmemServer *server, int64_t peer_id); |
a75eb03b DM |
155 | |
156 | /** | |
157 | * Dump information of this ivshmem server and its peers on stdout | |
158 | * | |
159 | * @server: The ivshmem server | |
160 | */ | |
161 | void ivshmem_server_dump(const IvshmemServer *server); | |
162 | ||
2a6a4076 | 163 | #endif /* IVSHMEM_SERVER_H */ |