f7a199b2b4
The current ivshmem protocol uses 'long' for integers. But the sizeof(long) depends on the host and the endianess is not defined, which may cause portability troubles. Instead, switch to using little-endian int64_t. This breaks the protocol, except on x64 little-endian host where this change should be compatible. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
214 lines
6.8 KiB
C
214 lines
6.8 KiB
C
/*
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* Copyright 6WIND S.A., 2014
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or
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* (at your option) any later version. See the COPYING file in the
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* top-level directory.
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*/
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#ifndef _IVSHMEM_CLIENT_H_
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#define _IVSHMEM_CLIENT_H_
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/**
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* This file provides helper to implement an ivshmem client. It is used
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* on the host to ask QEMU to send an interrupt to an ivshmem PCI device in a
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* guest. QEMU also implements an ivshmem client similar to this one, they both
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* connect to an ivshmem server.
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*
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* A standalone ivshmem client based on this file is provided for debug/test
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* purposes.
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*/
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#include <limits.h>
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#include <sys/select.h>
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#include "qemu/queue.h"
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#include "hw/misc/ivshmem.h"
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/**
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* Maximum number of notification vectors supported by the client
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*/
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#define IVSHMEM_CLIENT_MAX_VECTORS 64
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/**
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* Structure storing a peer
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*
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* Each time a client connects to an ivshmem server, it is advertised to
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* all connected clients through the unix socket. When our ivshmem
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* client receives a notification, it creates a IvshmemClientPeer
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* structure to store the infos of this peer.
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*
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* This structure is also used to store the information of our own
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* client in (IvshmemClient)->local.
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*/
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typedef struct IvshmemClientPeer {
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QTAILQ_ENTRY(IvshmemClientPeer) next; /**< next in list*/
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int64_t id; /**< the id of the peer */
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int vectors[IVSHMEM_CLIENT_MAX_VECTORS]; /**< one fd per vector */
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unsigned vectors_count; /**< number of vectors */
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} IvshmemClientPeer;
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QTAILQ_HEAD(IvshmemClientPeerList, IvshmemClientPeer);
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typedef struct IvshmemClientPeerList IvshmemClientPeerList;
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typedef struct IvshmemClient IvshmemClient;
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/**
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* Typedef of callback function used when our IvshmemClient receives a
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* notification from a peer.
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*/
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typedef void (*IvshmemClientNotifCb)(
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const IvshmemClient *client,
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const IvshmemClientPeer *peer,
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unsigned vect, void *arg);
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/**
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* Structure describing an ivshmem client
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*
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* This structure stores all information related to our client: the name
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* of the server unix socket, the list of peers advertised by the
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* server, our own client information, and a pointer the notification
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* callback function used when we receive a notification from a peer.
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*/
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struct IvshmemClient {
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char unix_sock_path[PATH_MAX]; /**< path to unix sock */
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int sock_fd; /**< unix sock filedesc */
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int shm_fd; /**< shm file descriptor */
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IvshmemClientPeerList peer_list; /**< list of peers */
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IvshmemClientPeer local; /**< our own infos */
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IvshmemClientNotifCb notif_cb; /**< notification callback */
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void *notif_arg; /**< notification argument */
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bool verbose; /**< true to enable debug */
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};
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/**
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* Initialize an ivshmem client
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*
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* @client: A pointer to an uninitialized IvshmemClient structure
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* @unix_sock_path: The pointer to the unix socket file name
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* @notif_cb: If not NULL, the pointer to the function to be called when
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* our IvshmemClient receives a notification from a peer
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* @notif_arg: Opaque pointer given as-is to the notification callback
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* function
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* @verbose: True to enable debug
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*
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* Returns: 0 on success, or a negative value on error
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*/
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int ivshmem_client_init(IvshmemClient *client, const char *unix_sock_path,
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IvshmemClientNotifCb notif_cb, void *notif_arg,
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bool verbose);
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/**
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* Connect to the server
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*
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* Connect to the server unix socket, and read the first initial
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* messages sent by the server, giving the ID of the client and the file
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* descriptor of the shared memory.
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*
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* @client: The ivshmem client
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*
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* Returns: 0 on success, or a negative value on error
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*/
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int ivshmem_client_connect(IvshmemClient *client);
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/**
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* Close connection to the server and free all peer structures
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*
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* @client: The ivshmem client
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*/
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void ivshmem_client_close(IvshmemClient *client);
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/**
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* Fill a fd_set with file descriptors to be monitored
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*
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* This function will fill a fd_set with all file descriptors
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* that must be polled (unix server socket and peers eventfd). The
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* function will not initialize the fd_set, it is up to the caller
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* to do this.
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*
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* @client: The ivshmem client
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* @fds: The fd_set to be updated
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* @maxfd: Must be set to the max file descriptor + 1 in fd_set. This value is
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* updated if this function adds a greater fd in fd_set.
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*/
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void ivshmem_client_get_fds(const IvshmemClient *client, fd_set *fds,
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int *maxfd);
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/**
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* Read and handle new messages
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*
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* Given a fd_set filled by select(), handle incoming messages from
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* server or peers.
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*
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* @client: The ivshmem client
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* @fds: The fd_set containing the file descriptors to be checked. Note
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* that file descriptors that are not related to our client are
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* ignored.
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* @maxfd: The maximum fd in fd_set, plus one.
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*
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* Returns: 0 on success, or a negative value on error
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*/
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int ivshmem_client_handle_fds(IvshmemClient *client, fd_set *fds, int maxfd);
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/**
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* Send a notification to a vector of a peer
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*
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* @client: The ivshmem client
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* @peer: The peer to be notified
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* @vector: The number of the vector
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*
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* Returns: 0 on success, or a negative value on error
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*/
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int ivshmem_client_notify(const IvshmemClient *client,
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const IvshmemClientPeer *peer, unsigned vector);
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/**
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* Send a notification to all vectors of a peer
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*
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* @client: The ivshmem client
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* @peer: The peer to be notified
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*
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* Returns: 0 on success, or a negative value on error (at least one
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* notification failed)
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*/
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int ivshmem_client_notify_all_vects(const IvshmemClient *client,
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const IvshmemClientPeer *peer);
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/**
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* Broadcat a notification to all vectors of all peers
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*
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* @client: The ivshmem client
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*
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* Returns: 0 on success, or a negative value on error (at least one
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* notification failed)
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*/
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int ivshmem_client_notify_broadcast(const IvshmemClient *client);
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/**
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* Search a peer from its identifier
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*
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* Return the peer structure from its peer_id. If the given peer_id is
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* the local id, the function returns the local peer structure.
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*
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* @client: The ivshmem client
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* @peer_id: The identifier of the peer structure
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*
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* Returns: The peer structure, or NULL if not found
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*/
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IvshmemClientPeer *
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ivshmem_client_search_peer(IvshmemClient *client, int64_t peer_id);
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/**
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* Dump information of this ivshmem client on stdout
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*
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* Dump the id and the vectors of the given ivshmem client and the list
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* of its peers and their vectors on stdout.
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*
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* @client: The ivshmem client
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*/
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void ivshmem_client_dump(const IvshmemClient *client);
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#endif /* _IVSHMEM_CLIENT_H_ */
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