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+/*
+ * Copyright 6WIND S.A., 2014
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * (at your option) any later version. See the COPYING file in the
+ * top-level directory.
+ */
+
+#ifndef _IVSHMEM_SERVER_H_
+#define _IVSHMEM_SERVER_H_
+
+/**
+ * The ivshmem server is a daemon that creates a unix socket in listen
+ * mode. The ivshmem clients (qemu or ivshmem-client) connect to this
+ * unix socket. For each client, the server will create some eventfd
+ * (see EVENTFD(2)), one per vector. These fd are transmitted to all
+ * clients using the SCM_RIGHTS cmsg message. Therefore, each client is
+ * able to send a notification to another client without beeing
+ * "profixied" by the server.
+ *
+ * We use this mechanism to send interruptions between guests.
+ * qemu is able to transform an event on a eventfd into a PCI MSI-x
+ * interruption in the guest.
+ *
+ * The ivshmem server is also able to share the file descriptor
+ * associated to the ivshmem shared memory.
+ */
+
+#include <sys/select.h>
+
+#include "qemu/event_notifier.h"
+#include "qemu/queue.h"
+#include "hw/misc/ivshmem.h"
+
+/**
+ * Maximum number of notification vectors supported by the server
+ */
+#define IVSHMEM_SERVER_MAX_VECTORS 64
+
+/**
+ * Structure storing a peer
+ *
+ * Each time a client connects to an ivshmem server, a new
+ * IvshmemServerPeer structure is created. This peer and all its
+ * vectors are advertised to all connected clients through the connected
+ * unix sockets.
+ */
+typedef struct IvshmemServerPeer {
+ QTAILQ_ENTRY(IvshmemServerPeer) next; /**< next in list*/
+ int sock_fd; /**< connected unix sock */
+ int64_t id; /**< the id of the peer */
+ EventNotifier vectors[IVSHMEM_SERVER_MAX_VECTORS]; /**< one per vector */
+ unsigned vectors_count; /**< number of vectors */
+} IvshmemServerPeer;
+QTAILQ_HEAD(IvshmemServerPeerList, IvshmemServerPeer);
+
+typedef struct IvshmemServerPeerList IvshmemServerPeerList;
+
+/**
+ * Structure describing an ivshmem server
+ *
+ * This structure stores all information related to our server: the name
+ * of the server unix socket and the list of connected peers.
+ */
+typedef struct IvshmemServer {
+ char unix_sock_path[PATH_MAX]; /**< path to unix socket */
+ int sock_fd; /**< unix sock file descriptor */
+ char shm_path[PATH_MAX]; /**< path to shm */
+ bool use_shm_open;
+ size_t shm_size; /**< size of shm */
+ int shm_fd; /**< shm file descriptor */
+ unsigned n_vectors; /**< number of vectors */
+ uint16_t cur_id; /**< id to be given to next client */
+ bool verbose; /**< true in verbose mode */
+ IvshmemServerPeerList peer_list; /**< list of peers */
+} IvshmemServer;
+
+/**
+ * Initialize an ivshmem server
+ *
+ * @server: A pointer to an uninitialized IvshmemServer structure
+ * @unix_sock_path: The pointer to the unix socket file name
+ * @shm_path: Path to the shared memory. The path corresponds to a POSIX
+ * shm name or a hugetlbfs mount point.
+ * @shm_size: Size of shared memory
+ * @n_vectors: Number of interrupt vectors per client
+ * @verbose: True to enable verbose mode
+ *
+ * Returns: 0 on success, or a negative value on error
+ */
+int
+ivshmem_server_init(IvshmemServer *server, const char *unix_sock_path,
+ const char *shm_path, bool use_shm_open,
+ size_t shm_size, unsigned n_vectors,
+ bool verbose);
+
+/**
+ * Open the shm, then create and bind to the unix socket
+ *
+ * @server: The pointer to the initialized IvshmemServer structure
+ *
+ * Returns: 0 on success, or a negative value on error
+ */
+int ivshmem_server_start(IvshmemServer *server);
+
+/**
+ * Close the server
+ *
+ * Close connections to all clients, close the unix socket and the
+ * shared memory file descriptor. The structure remains initialized, so
+ * it is possible to call ivshmem_server_start() again after a call to
+ * ivshmem_server_close().
+ *
+ * @server: The ivshmem server
+ */
+void ivshmem_server_close(IvshmemServer *server);
+
+/**
+ * Fill a fd_set with file descriptors to be monitored
+ *
+ * This function will fill a fd_set with all file descriptors that must
+ * be polled (unix server socket and peers unix socket). The function
+ * will not initialize the fd_set, it is up to the caller to do it.
+ *
+ * @server: The ivshmem server
+ * @fds: The fd_set to be updated
+ * @maxfd: Must be set to the max file descriptor + 1 in fd_set. This value is
+ * updated if this function adds a greater fd in fd_set.
+ */
+void
+ivshmem_server_get_fds(const IvshmemServer *server, fd_set *fds, int *maxfd);
+
+/**
+ * Read and handle new messages
+ *
+ * Given a fd_set (for instance filled by a call to select()), handle
+ * incoming messages from peers.
+ *
+ * @server: The ivshmem server
+ * @fds: The fd_set containing the file descriptors to be checked. Note that
+ * file descriptors that are not related to our server are ignored.
+ * @maxfd: The maximum fd in fd_set, plus one.
+ *
+ * Returns: 0 on success, or a negative value on error
+ */
+int ivshmem_server_handle_fds(IvshmemServer *server, fd_set *fds, int maxfd);
+
+/**
+ * Search a peer from its identifier
+ *
+ * @server: The ivshmem server
+ * @peer_id: The identifier of the peer structure
+ *
+ * Returns: The peer structure, or NULL if not found
+ */
+IvshmemServerPeer *
+ivshmem_server_search_peer(IvshmemServer *server, int64_t peer_id);
+
+/**
+ * Dump information of this ivshmem server and its peers on stdout
+ *
+ * @server: The ivshmem server
+ */
+void ivshmem_server_dump(const IvshmemServer *server);
+
+#endif /* _IVSHMEM_SERVER_H_ */