diff options
| -rw-r--r-- | Makefile | 7 | ||||
| -rw-r--r-- | Makefile.objs | 5 | ||||
| -rwxr-xr-x | configure | 1 | ||||
| -rw-r--r-- | contrib/ivshmem-client/Makefile.objs | 1 | ||||
| -rw-r--r-- | contrib/ivshmem-client/ivshmem-client.c | 433 | ||||
| -rw-r--r-- | contrib/ivshmem-client/ivshmem-client.h | 212 | ||||
| -rw-r--r-- | contrib/ivshmem-client/main.c | 239 | ||||
| -rw-r--r-- | contrib/ivshmem-server/Makefile.objs | 1 | ||||
| -rw-r--r-- | contrib/ivshmem-server/ivshmem-server.c | 422 | ||||
| -rw-r--r-- | contrib/ivshmem-server/ivshmem-server.h | 167 | ||||
| -rw-r--r-- | contrib/ivshmem-server/main.c | 264 | ||||
| -rw-r--r-- | qemu-doc.texi | 10 |
12 files changed, 1759 insertions, 3 deletions
@@ -151,6 +151,8 @@ dummy := $(call unnest-vars,, \ stub-obj-y \ util-obj-y \ qga-obj-y \ + ivshmem-client-obj-y \ + ivshmem-server-obj-y \ qga-vss-dll-obj-y \ block-obj-y \ block-obj-m \ @@ -323,6 +325,11 @@ ifneq ($(EXESUF),) qemu-ga: qemu-ga$(EXESUF) $(QGA_VSS_PROVIDER) $(QEMU_GA_MSI) endif +ivshmem-client$(EXESUF): $(ivshmem-client-obj-y) + $(call LINK, $^) +ivshmem-server$(EXESUF): $(ivshmem-server-obj-y) libqemuutil.a libqemustub.a + $(call LINK, $^) + clean: # avoid old build problems by removing potentially incorrect old files rm -f config.mak op-i386.h opc-i386.h gen-op-i386.h op-arm.h opc-arm.h gen-op-arm.h diff --git a/Makefile.objs b/Makefile.objs index ecfe03c195..fe02ee2cf4 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -104,3 +104,8 @@ target-obj-y += trace/ # by libqemuutil.a. These should be moved to a separate .json schema. qga-obj-y = qga/ qga-vss-dll-obj-y = qga/ + +###################################################################### +# contrib +ivshmem-client-obj-y = contrib/ivshmem-client/ +ivshmem-server-obj-y = contrib/ivshmem-server/ @@ -4508,6 +4508,7 @@ if test "$want_tools" = "yes" ; then tools="qemu-img\$(EXESUF) qemu-io\$(EXESUF) $tools" if [ "$linux" = "yes" -o "$bsd" = "yes" -o "$solaris" = "yes" ] ; then tools="qemu-nbd\$(EXESUF) $tools" + tools="ivshmem-client\$(EXESUF) ivshmem-server\$(EXESUF) $tools" fi fi if test "$softmmu" = yes ; then diff --git a/contrib/ivshmem-client/Makefile.objs b/contrib/ivshmem-client/Makefile.objs new file mode 100644 index 0000000000..bfab2d20dd --- /dev/null +++ b/contrib/ivshmem-client/Makefile.objs @@ -0,0 +1 @@ +ivshmem-client-obj-y = ivshmem-client.o main.o diff --git a/contrib/ivshmem-client/ivshmem-client.c b/contrib/ivshmem-client/ivshmem-client.c new file mode 100644 index 0000000000..fcc0930eb6 --- /dev/null +++ b/contrib/ivshmem-client/ivshmem-client.c @@ -0,0 +1,433 @@ +/* + * 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. + */ + +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/un.h> + +#include "qemu-common.h" +#include "qemu/queue.h" + +#include "ivshmem-client.h" + +/* log a message on stdout if verbose=1 */ +#define IVSHMEM_CLIENT_DEBUG(client, fmt, ...) do { \ + if ((client)->verbose) { \ + printf(fmt, ## __VA_ARGS__); \ + } \ + } while (0) + +/* read message from the unix socket */ +static int +ivshmem_client_read_one_msg(IvshmemClient *client, long *index, int *fd) +{ + int ret; + struct msghdr msg; + struct iovec iov[1]; + union { + struct cmsghdr cmsg; + char control[CMSG_SPACE(sizeof(int))]; + } msg_control; + struct cmsghdr *cmsg; + + iov[0].iov_base = index; + iov[0].iov_len = sizeof(*index); + + memset(&msg, 0, sizeof(msg)); + msg.msg_iov = iov; + msg.msg_iovlen = 1; + msg.msg_control = &msg_control; + msg.msg_controllen = sizeof(msg_control); + + ret = recvmsg(client->sock_fd, &msg, 0); + if (ret < 0) { + IVSHMEM_CLIENT_DEBUG(client, "cannot read message: %s\n", + strerror(errno)); + return -1; + } + if (ret == 0) { + IVSHMEM_CLIENT_DEBUG(client, "lost connection to server\n"); + return -1; + } + + *fd = -1; + + for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { + + if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)) || + cmsg->cmsg_level != SOL_SOCKET || + cmsg->cmsg_type != SCM_RIGHTS) { + continue; + } + + memcpy(fd, CMSG_DATA(cmsg), sizeof(*fd)); + } + + return 0; +} + +/* free a peer when the server advertises a disconnection or when the + * client is freed */ +static void +ivshmem_client_free_peer(IvshmemClient *client, IvshmemClientPeer *peer) +{ + unsigned vector; + + QTAILQ_REMOVE(&client->peer_list, peer, next); + for (vector = 0; vector < peer->vectors_count; vector++) { + close(peer->vectors[vector]); + } + + g_free(peer); +} + +/* handle message coming from server (new peer, new vectors) */ +static int +ivshmem_client_handle_server_msg(IvshmemClient *client) +{ + IvshmemClientPeer *peer; + long peer_id; + int ret, fd; + + ret = ivshmem_client_read_one_msg(client, &peer_id, &fd); + if (ret < 0) { + return -1; + } + + /* can return a peer or the local client */ + peer = ivshmem_client_search_peer(client, peer_id); + + /* delete peer */ + if (fd == -1) { + + if (peer == NULL || peer == &client->local) { + IVSHMEM_CLIENT_DEBUG(client, "receive delete for invalid " + "peer %ld\n", peer_id); + return -1; + } + + IVSHMEM_CLIENT_DEBUG(client, "delete peer id = %ld\n", peer_id); + ivshmem_client_free_peer(client, peer); + return 0; + } + + /* new peer */ + if (peer == NULL) { + peer = g_malloc0(sizeof(*peer)); + peer->id = peer_id; + peer->vectors_count = 0; + QTAILQ_INSERT_TAIL(&client->peer_list, peer, next); + IVSHMEM_CLIENT_DEBUG(client, "new peer id = %ld\n", peer_id); + } + + /* new vector */ + IVSHMEM_CLIENT_DEBUG(client, " new vector %d (fd=%d) for peer id %ld\n", + peer->vectors_count, fd, peer->id); + peer->vectors[peer->vectors_count] = fd; + peer->vectors_count++; + + return 0; +} + +/* init a new ivshmem client */ +int +ivshmem_client_init(IvshmemClient *client, const char *unix_sock_path, + IvshmemClientNotifCb notif_cb, void *notif_arg, + bool verbose) +{ + int ret; + unsigned i; + + memset(client, 0, sizeof(*client)); + + ret = snprintf(client->unix_sock_path, sizeof(client->unix_sock_path), + "%s", unix_sock_path); + + if (ret < 0 || ret >= sizeof(client->unix_sock_path)) { + IVSHMEM_CLIENT_DEBUG(client, "could not copy unix socket path\n"); + return -1; + } + + for (i = 0; i < IVSHMEM_CLIENT_MAX_VECTORS; i++) { + client->local.vectors[i] = -1; + } + + QTAILQ_INIT(&client->peer_list); + client->local.id = -1; + + client->notif_cb = notif_cb; + client->notif_arg = notif_arg; + client->verbose = verbose; + client->shm_fd = -1; + client->sock_fd = -1; + + return 0; +} + +/* create and connect to the unix socket */ +int +ivshmem_client_connect(IvshmemClient *client) +{ + struct sockaddr_un sun; + int fd, ret; + long tmp; + + IVSHMEM_CLIENT_DEBUG(client, "connect to client %s\n", + client->unix_sock_path); + + client->sock_fd = socket(AF_UNIX, SOCK_STREAM, 0); + if (client->sock_fd < 0) { + IVSHMEM_CLIENT_DEBUG(client, "cannot create socket: %s\n", + strerror(errno)); + return -1; + } + + sun.sun_family = AF_UNIX; + ret = snprintf(sun.sun_path, sizeof(sun.sun_path), "%s", + client->unix_sock_path); + if (ret < 0 || ret >= sizeof(sun.sun_path)) { + IVSHMEM_CLIENT_DEBUG(client, "could not copy unix socket path\n"); + goto err_close; + } + + if (connect(client->sock_fd, (struct sockaddr *)&sun, sizeof(sun)) < 0) { + IVSHMEM_CLIENT_DEBUG(client, "cannot connect to %s: %s\n", sun.sun_path, + strerror(errno)); + goto err_close; + } + + /* first, we expect our index + a fd == -1 */ + if (ivshmem_client_read_one_msg(client, &client->local.id, &fd) < 0 || + client->local.id < 0 || fd != -1) { + IVSHMEM_CLIENT_DEBUG(client, "cannot read from server\n"); + goto err_close; + } + IVSHMEM_CLIENT_DEBUG(client, "our_id=%ld\n", client->local.id); + + /* now, we expect shared mem fd + a -1 index, note that shm fd + * is not used */ + if (ivshmem_client_read_one_msg(client, &tmp, &fd) < 0 || + tmp != -1 || fd < 0) { + if (fd >= 0) { + close(fd); + } + IVSHMEM_CLIENT_DEBUG(client, "cannot read from server (2)\n"); + goto err_close; + } + client->shm_fd = fd; + IVSHMEM_CLIENT_DEBUG(client, "shm_fd=%d\n", fd); + + return 0; + +err_close: + close(client->sock_fd); + client->sock_fd = -1; + return -1; +} + +/* close connection to the server, and free all peer structures */ +void +ivshmem_client_close(IvshmemClient *client) +{ + IvshmemClientPeer *peer; + unsigned i; + + IVSHMEM_CLIENT_DEBUG(client, "close client\n"); + + while ((peer = QTAILQ_FIRST(&client->peer_list)) != NULL) { + ivshmem_client_free_peer(client, peer); + } + + close(client->shm_fd); + client->shm_fd = -1; + close(client->sock_fd); + client->sock_fd = -1; + client->local.id = -1; + for (i = 0; i < IVSHMEM_CLIENT_MAX_VECTORS; i++) { + close(client->local.vectors[i]); + client->local.vectors[i] = -1; + } + client->local.vectors_count = 0; +} + +/* get the fd_set according to the unix socket and peer list */ +void +ivshmem_client_get_fds(const IvshmemClient *client, fd_set *fds, int *maxfd) +{ + int fd; + unsigned vector; + + FD_SET(client->sock_fd, fds); + if (client->sock_fd >= *maxfd) { + *maxfd = client->sock_fd + 1; + } + + for (vector = 0; vector < client->local.vectors_count; vector++) { + fd = client->local.vectors[vector]; + FD_SET(fd, fds); + if (fd >= *maxfd) { + *maxfd = fd + 1; + } + } +} + +/* handle events from eventfd: just print a message on notification */ +static int +ivshmem_client_handle_event(IvshmemClient *client, const fd_set *cur, int maxfd) +{ + IvshmemClientPeer *peer; + uint64_t kick; + unsigned i; + int ret; + + peer = &client->local; + + for (i = 0; i < peer->vectors_count; i++) { + if (peer->vectors[i] >= maxfd || !FD_ISSET(peer->vectors[i], cur)) { + continue; + } + + ret = read(peer->vectors[i], &kick, sizeof(kick)); + if (ret < 0) { + return ret; + } + if (ret != sizeof(kick)) { + IVSHMEM_CLIENT_DEBUG(client, "invalid read size = %d\n", ret); + errno = EINVAL; + return -1; + } + IVSHMEM_CLIENT_DEBUG(client, "received event on fd %d vector %d: %" + PRIu64 "\n", peer->vectors[i], i, kick); + if (client->notif_cb != NULL) { + client->notif_cb(client, peer, i, client->notif_arg); + } + } + + return 0; +} + +/* read and handle new messages on the given fd_set */ +int +ivshmem_client_handle_fds(IvshmemClient *client, fd_set *fds, int maxfd) +{ + if (client->sock_fd < maxfd && FD_ISSET(client->sock_fd, fds) && + ivshmem_client_handle_server_msg(client) < 0 && errno != EINTR) { + IVSHMEM_CLIENT_DEBUG(client, "ivshmem_client_handle_server_msg() " + "failed\n"); + return -1; + } else if (ivshmem_client_handle_event(client, fds, maxfd) < 0 && + errno != EINTR) { + IVSHMEM_CLIENT_DEBUG(client, "ivshmem_client_handle_event() failed\n"); + return -1; + } + + return 0; +} + +/* send a notification on a vector of a peer */ +int +ivshmem_client_notify(const IvshmemClient *client, + const IvshmemClientPeer *peer, unsigned vector) +{ + uint64_t kick; + int fd; + + if (vector >= peer->vectors_count) { + IVSHMEM_CLIENT_DEBUG(client, "invalid vector %u on peer %ld\n", + vector, peer->id); + return -1; + } + fd = peer->vectors[vector]; + IVSHMEM_CLIENT_DEBUG(client, "notify peer %ld on vector %d, fd %d\n", + peer->id, vector, fd); + + kick = 1; + if (write(fd, &kick, sizeof(kick)) != sizeof(kick)) { + fprintf(stderr, "could not write to %d: %s\n", peer->vectors[vector], + strerror(errno)); + return -1; + } + return 0; +} + +/* send a notification to all vectors of a peer */ +int +ivshmem_client_notify_all_vects(const IvshmemClient *client, + const IvshmemClientPeer *peer) +{ + unsigned vector; + int ret = 0; + + for (vector = 0; vector < peer->vectors_count; vector++) { + if (ivshmem_client_notify(client, peer, vector) < 0) { + ret = -1; + } + } + + return ret; +} + +/* send a notification to all peers */ +int +ivshmem_client_notify_broadcast(const IvshmemClient *client) +{ + IvshmemClientPeer *peer; + int ret = 0; + + QTAILQ_FOREACH(peer, &client->peer_list, next) { + if (ivshmem_client_notify_all_vects(client, peer) < 0) { + ret = -1; + } + } + + return ret; +} + +/* lookup peer from its id */ +IvshmemClientPeer * +ivshmem_client_search_peer(IvshmemClient *client, long peer_id) +{ + IvshmemClientPeer *peer; + + if (peer_id == client->local.id) { + return &client->local; + } + + QTAILQ_FOREACH(peer, &client->peer_list, next) { + if (peer->id == peer_id) { + return peer; + } + } + return NULL; +} + +/* dump our info, the list of peers their vectors on stdout */ +void +ivshmem_client_dump(const IvshmemClient *client) +{ + const IvshmemClientPeer *peer; + unsigned vector; + + /* dump local infos */ + peer = &client->local; + printf("our_id = %ld\n", peer->id); + for (vector = 0; vector < peer->vectors_count; vector++) { + printf(" vector %d is enabled (fd=%d)\n", vector, + peer->vectors[vector]); + } + + /* dump peers */ + QTAILQ_FOREACH(peer, &client->peer_list, next) { + printf("peer_id = %ld\n", peer->id); + + for (vector = 0; vector < peer->vectors_count; vector++) { + printf(" vector %d is enabled (fd=%d)\n", vector, + peer->vectors[vector]); + } + } +} diff --git a/contrib/ivshmem-client/ivshmem-client.h b/contrib/ivshmem-client/ivshmem-client.h new file mode 100644 index 0000000000..284c4a37fb --- /dev/null +++ b/contrib/ivshmem-client/ivshmem-client.h @@ -0,0 +1,212 @@ +/* + * 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_CLIENT_H_ +#define _IVSHMEM_CLIENT_H_ + +/** + * This file provides helper to implement an ivshmem client. It is used + * on the host to ask QEMU to send an interrupt to an ivshmem PCI device in a + * guest. QEMU also implements an ivshmem client similar to this one, they both + * connect to an ivshmem server. + * + * A standalone ivshmem client based on this file is provided for debug/test + * purposes. + */ + +#include <limits.h> +#include <sys/select.h> + +#include "qemu/queue.h" + +/** + * Maximum number of notification vectors supported by the client + */ +#define IVSHMEM_CLIENT_MAX_VECTORS 64 + +/** + * Structure storing a peer + * + * Each time a client connects to an ivshmem server, it is advertised to + * all connected clients through the unix socket. When our ivshmem + * client receives a notification, it creates a IvshmemClientPeer + * structure to store the infos of this peer. + * + * This structure is also used to store the information of our own + * client in (IvshmemClient)->local. + */ +typedef struct IvshmemClientPeer { + QTAILQ_ENTRY(IvshmemClientPeer) next; /**< next in list*/ + long id; /**< the id of the peer */ + int vectors[IVSHMEM_CLIENT_MAX_VECTORS]; /**< one fd per vector */ + unsigned vectors_count; /**< number of vectors */ +} IvshmemClientPeer; +QTAILQ_HEAD(IvshmemClientPeerList, IvshmemClientPeer); + +typedef struct IvshmemClientPeerList IvshmemClientPeerList; +typedef struct IvshmemClient IvshmemClient; + +/** + * Typedef of callback function used when our IvshmemClient receives a + * notification from a peer. + */ +typedef void (*IvshmemClientNotifCb)( + const IvshmemClient *client, + const IvshmemClientPeer *peer, + unsigned vect, void *arg); + +/** + * Structure describing an ivshmem client + * + * This structure stores all information related to our client: the name + * of the server unix socket, the list of peers advertised by the + * server, our own client information, and a pointer the notification + * callback function used when we receive a notification from a peer. + */ +struct IvshmemClient { + char unix_sock_path[PATH_MAX]; /**< path to unix sock */ + int sock_fd; /**< unix sock filedesc */ + int shm_fd; /**< shm file descriptor */ + + IvshmemClientPeerList peer_list; /**< list of peers */ + IvshmemClientPeer local; /**< our own infos */ + + IvshmemClientNotifCb notif_cb; /**< notification callback */ + void *notif_arg; /**< notification argument */ + + bool verbose; /**< true to enable debug */ +}; + +/** + * Initialize an ivshmem client + * + * @client: A pointer to an uninitialized IvshmemClient structure + * @unix_sock_path: The pointer to the unix socket file name + * @notif_cb: If not NULL, the pointer to the function to be called when + * our IvshmemClient receives a notification from a peer + * @notif_arg: Opaque pointer given as-is to the notification callback + * function + * @verbose: True to enable debug + * + * Returns: 0 on success, or a negative value on error + */ +int ivshmem_client_init(IvshmemClient *client, const char *unix_sock_path, + IvshmemClientNotifCb notif_cb, void *notif_arg, + bool verbose); + +/** + * Connect to the server + * + * Connect to the server unix socket, and read the first initial + * messages sent by the server, giving the ID of the client and the file + * descriptor of the shared memory. + * + * @client: The ivshmem client + * + * Returns: 0 on success, or a negative value on error + */ +int ivshmem_client_connect(IvshmemClient *client); + +/** + * Close connection to the server and free all peer structures + * + * @client: The ivshmem client + */ +void ivshmem_client_close(IvshmemClient *client); + +/** + * 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 eventfd). The + * function will not initialize the fd_set, it is up to the caller + * to do this. + * + * @client: The ivshmem client + * @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_client_get_fds(const IvshmemClient *client, fd_set *fds, + int *maxfd); + +/** + * Read and handle new messages + * + * Given a fd_set filled by select(), handle incoming messages from + * server or peers. + * + * @client: The ivshmem client + * @fds: The fd_set containing the file descriptors to be checked. Note + * that file descriptors that are not related to our client are + * ignored. + * @maxfd: The maximum fd in fd_set, plus one. + * + * Returns: 0 on success, or a negative value on error + */ +int ivshmem_client_handle_fds(IvshmemClient *client, fd_set *fds, int maxfd); + +/** + * Send a notification to a vector of a peer + * + * @client: The ivshmem client + * @peer: The peer to be notified + * @vector: The number of the vector + * + * Returns: 0 on success, or a negative value on error + */ +int ivshmem_client_notify(const IvshmemClient *client, + const IvshmemClientPeer *peer, unsigned vector); + +/** + * Send a notification to all vectors of a peer + * + * @client: The ivshmem client + * @peer: The peer to be notified + * + * Returns: 0 on success, or a negative value on error (at least one + * notification failed) + */ +int ivshmem_client_notify_all_vects(const IvshmemClient *client, + const IvshmemClientPeer *peer); + +/** + * Broadcat a notification to all vectors of all peers + * + * @client: The ivshmem client + * + * Returns: 0 on success, or a negative value on error (at least one + * notification failed) + */ +int ivshmem_client_notify_broadcast(const IvshmemClient *client); + +/** + * Search a peer from its identifier + * + * Return the peer structure from its peer_id. If the given peer_id is + * the local id, the function returns the local peer structure. + * + * @client: The ivshmem client + * @peer_id: The identifier of the peer structure + * + * Returns: The peer structure, or NULL if not found + */ +IvshmemClientPeer * +ivshmem_client_search_peer(IvshmemClient *client, long peer_id); + +/** + * Dump information of this ivshmem client on stdout + * + * Dump the id and the vectors of the given ivshmem client and the list + * of its peers and their vectors on stdout. + * + * @client: The ivshmem client + */ +void ivshmem_client_dump(const IvshmemClient *client); + +#endif /* _IVSHMEM_CLIENT_H_ */ diff --git a/contrib/ivshmem-client/main.c b/contrib/ivshmem-client/main.c new file mode 100644 index 0000000000..44531f57be --- /dev/null +++ b/contrib/ivshmem-client/main.c @@ -0,0 +1,239 @@ +/* + * 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. + */ + +#include "qemu-common.h" + +#include "ivshmem-client.h" + +#define IVSHMEM_CLIENT_DEFAULT_VERBOSE 0 +#define IVSHMEM_CLIENT_DEFAULT_UNIX_SOCK_PATH "/tmp/ivshmem_socket" + +typedef struct IvshmemClientArgs { + bool verbose; + const char *unix_sock_path; +} IvshmemClientArgs; + +/* show ivshmem_client_usage and exit with given error code */ +static void +ivshmem_client_usage(const char *name, int code) +{ + fprintf(stderr, "%s [opts]\n", name); + fprintf(stderr, " -h: show this help\n"); + fprintf(stderr, " -v: verbose mode\n"); + fprintf(stderr, " -S <unix_sock_path>: path to the unix socket\n" + " to connect to.\n" + " default=%s\n", IVSHMEM_CLIENT_DEFAULT_UNIX_SOCK_PATH); + exit(code); +} + +/* parse the program arguments, exit on error */ +static void +ivshmem_client_parse_args(IvshmemClientArgs *args, int argc, char *argv[]) +{ + int c; + + while ((c = getopt(argc, argv, + "h" /* help */ + "v" /* verbose */ + "S:" /* unix_sock_path */ + )) != -1) { + + switch (c) { + case 'h': /* help */ + ivshmem_client_usage(argv[0], 0); + break; + + case 'v': /* verbose */ + args->verbose = 1; + break; + + case 'S': /* unix_sock_path */ + args->unix_sock_path = strdup(optarg); + break; + + default: + ivshmem_client_usage(argv[0], 1); + break; + } + } +} + +/* show command line help */ +static void +ivshmem_client_cmdline_help(void) +{ + printf("dump: dump peers (including us)\n" + "int <peer> <vector>: notify one vector on a peer\n" + "int <peer> all: notify all vectors of a peer\n" + "int all: notify all vectors of all peers (excepting us)\n"); +} + +/* read stdin and handle commands */ +static int +ivshmem_client_handle_stdin_command(IvshmemClient *client) +{ + IvshmemClientPeer *peer; + char buf[128]; + char *s, *token; + int ret; + int peer_id, vector; + + memset(buf, 0, sizeof(buf)); + ret = read(0, buf, sizeof(buf) - 1); + if (ret < 0) { + return -1; + } + + s = buf; + while ((token = strsep(&s, "\n\r;")) != NULL) { + if (!strcmp(token, "")) { + continue; + } + if (!strcmp(token, "?")) { + ivshmem_client_cmdline_help(); + } + if (!strcmp(token, "help")) { + ivshmem_client_cmdline_help(); + } else if (!strcmp(token, "dump")) { + ivshmem_client_dump(client); + } else if (!strcmp(token, "int all")) { + ivshmem_client_notify_broadcast(client); + } else if (sscanf(token, "int %d %d", &peer_id, &vector) == 2) { + peer = ivshmem_client_search_peer(client, peer_id); + if (peer == NULL) { + printf("cannot find peer_id = %d\n", peer_id); + continue; + } + ivshmem_client_notify(client, peer, vector); + } else if (sscanf(token, "int %d all", &peer_id) == 1) { + peer = ivshmem_client_search_peer(client, peer_id); + if (peer == NULL) { + printf("cannot find peer_id = %d\n", peer_id); + continue; + } + ivshmem_client_notify_all_vects(client, peer); + } else { + printf("invalid command, type help\n"); + } + } + + printf("cmd> "); + fflush(stdout); + return 0; +} + +/* listen on stdin (command line), on unix socket (notifications of new + * and dead peers), and on eventfd (IRQ request) */ +static int +ivshmem_client_poll_events(IvshmemClient *client) +{ + fd_set fds; + int ret, maxfd; + + while (1) { + + FD_ZERO(&fds); + FD_SET(0, &fds); /* add stdin in fd_set */ + maxfd = 1; + + ivshmem_client_get_fds(client, &fds, &maxfd); + + ret = select(maxfd, &fds, NULL, NULL, NULL); + if (ret < 0) { + if (errno == EINTR) { + continue; + } + + fprintf(stderr, "select error: %s\n", strerror(errno)); + break; + } + if (ret == 0) { + continue; + } + + if (FD_ISSET(0, &fds) && + ivshmem_client_handle_stdin_command(client) < 0 && errno != EINTR) { + fprintf(stderr, "ivshmem_client_handle_stdin_command() failed\n"); + break; + } + + if (ivshmem_client_handle_fds(client, &fds, maxfd) < 0) { + fprintf(stderr, "ivshmem_client_handle_fds() failed\n"); + break; + } + } + + return ret; +} + +/* callback when we receive a notification (just display it) */ +static void +ivshmem_client_notification_cb(const IvshmemClient *client, + const IvshmemClientPeer *peer, + unsigned vect, void *arg) +{ + (void)client; + (void)arg; + printf("receive notification from peer_id=%ld vector=%d\n", peer->id, vect); +} + +int +main(int argc, char *argv[]) +{ + struct sigaction sa; + IvshmemClient client; + IvshmemClientArgs args = { + .verbose = IVSHMEM_CLIENT_DEFAULT_VERBOSE, + .unix_sock_path = IVSHMEM_CLIENT_DEFAULT_UNIX_SOCK_PATH, + }; + + /* parse arguments, will exit on error */ + ivshmem_client_parse_args(&args, argc, argv); + + /* Ignore SIGPIPE, see this link for more info: + * http://www.mail-archive.com/libevent-users@monkey.org/msg01606.html */ + sa.sa_handler = SIG_IGN; + sa.sa_flags = 0; + if (sigemptyset(&sa.sa_mask) == -1 || + sigaction(SIGPIPE, &sa, 0) == -1) { + perror("failed to ignore SIGPIPE; sigaction"); + return 1; + } + + ivshmem_client_cmdline_help(); + printf("cmd> "); + fflush(stdout); + + if (ivshmem_client_init(&client, args.unix_sock_path, + ivshmem_client_notification_cb, NULL, + args.verbose) < 0) { + fprintf(stderr, "cannot init client\n"); + return 1; + } + + while (1) { + if (ivshmem_client_connect(&client) < 0) { + fprintf(stderr, "cannot connect to server, retry in 1 second\n"); + sleep(1); + continue; + } + + fprintf(stdout, "listen on server socket %d\n", client.sock_fd); + + if (ivshmem_client_poll_events(&client) == 0) { + continue; + } + + /* disconnected from server, reset all peers */ + fprintf(stdout, "disconnected from server\n"); + + ivshmem_client_close(&client); + } + + return 0; +} diff --git a/contrib/ivshmem-server/Makefile.objs b/contrib/ivshmem-server/Makefile.objs new file mode 100644 index 0000000000..c060dd3698 --- /dev/null +++ b/contrib/ivshmem-server/Makefile.objs @@ -0,0 +1 @@ +ivshmem-server-obj-y = ivshmem-server.o main.o diff --git a/contrib/ivshmem-server/ivshmem-server.c b/contrib/ivshmem-server/ivshmem-server.c new file mode 100644 index 0000000000..56b5df8ab7 --- /dev/null +++ b/contrib/ivshmem-server/ivshmem-server.c @@ -0,0 +1,422 @@ +/* + * 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. + */ +#include "qemu-common.h" +#include "qemu/sockets.h" + +#include <sys/mman.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/un.h> + +#include "ivshmem-server.h" + +/* log a message on stdout if verbose=1 */ +#define IVSHMEM_SERVER_DEBUG(server, fmt, ...) do { \ + if ((server)->verbose) { \ + printf(fmt, ## __VA_ARGS__); \ + } \ + } while (0) + +/** maximum size of a huge page, used by ivshmem_server_ftruncate() */ +#define IVSHMEM_SERVER_MAX_HUGEPAGE_SIZE (1024 * 1024 * 1024) + +/** default listen backlog (number of sockets not accepted) */ +#define IVSHMEM_SERVER_LISTEN_BACKLOG 10 + +/* send message to a client unix socket */ +static int +ivshmem_server_send_one_msg(int sock_fd, long peer_id, int fd) +{ + int ret; + struct msghdr msg; + struct iovec iov[1]; + union { + struct cmsghdr cmsg; + char control[CMSG_SPACE(sizeof(int))]; + } msg_control; + struct cmsghdr *cmsg; + + iov[0].iov_base = &peer_id; + iov[0].iov_len = sizeof(peer_id); + + memset(&msg, 0, sizeof(msg)); + msg.msg_iov = iov; + msg.msg_iovlen = 1; + + /* if fd is specified, add it in a cmsg */ + if (fd >= 0) { + memset(&msg_control, 0, sizeof(msg_control)); + msg.msg_control = &msg_control; + msg.msg_controllen = sizeof(msg_control); + cmsg = CMSG_FIRSTHDR(&msg); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + cmsg->cmsg_len = CMSG_LEN(sizeof(int)); + memcpy(CMSG_DATA(cmsg), &fd, sizeof(fd)); + } + + ret = sendmsg(sock_fd, &msg, 0); + if (ret <= 0) { + return -1; + } + + return 0; +} + +/* free a peer when the server advertises a disconnection or when the + * server is freed */ +static void +ivshmem_server_free_peer(IvshmemServer *server, IvshmemServerPeer *peer) +{ + unsigned vector; + IvshmemServerPeer *other_peer; + + IVSHMEM_SERVER_DEBUG(server, "free peer %ld\n", peer->id); + close(peer->sock_fd); + QTAILQ_REMOVE(&server->peer_list, peer, next); + + /* advertise the deletion to other peers */ + QTAILQ_FOREACH(other_peer, &server->peer_list, next) { + ivshmem_server_send_one_msg(other_peer->sock_fd, peer->id, -1); + } + + for (vector = 0; vector < peer->vectors_count; vector++) { + event_notifier_cleanup(&peer->vectors[vector]); + } + + g_free(peer); +} + +/* send the peer id and the shm_fd just after a new client connection */ +static int +ivshmem_server_send_initial_info(IvshmemServer *server, IvshmemServerPeer *peer) +{ + int ret; + + /* send the peer id to the client */ + ret = ivshmem_server_send_one_msg(peer->sock_fd, peer->id, -1); + if (ret < 0) { + IVSHMEM_SERVER_DEBUG(server, "cannot send peer id: %s\n", + strerror(errno)); + return -1; + } + + /* send the shm_fd */ + ret = ivshmem_server_send_one_msg(peer->sock_fd, -1, server->shm_fd); + if (ret < 0) { + IVSHMEM_SERVER_DEBUG(server, "cannot send shm fd: %s\n", + strerror(errno)); + return -1; + } + + return 0; +} + +/* handle message on listening unix socket (new client connection) */ +static int +ivshmem_server_handle_new_conn(IvshmemServer *server) +{ + IvshmemServerPeer *peer, *other_peer; + struct sockaddr_un unaddr; + socklen_t unaddr_len; + int newfd; + unsigned i; + + /* accept the incoming connection */ + unaddr_len = sizeof(unaddr); + newfd = qemu_accept(server->sock_fd, + (struct sockaddr *)&unaddr, &unaddr_len); + + if (newfd < 0) { + IVSHMEM_SERVER_DEBUG(server, "cannot accept() %s\n", strerror(errno)); + return -1; + } + + qemu_set_nonblock(newfd); + IVSHMEM_SERVER_DEBUG(server, "accept()=%d\n", newfd); + + /* allocate new structure for this peer */ + peer = g_malloc0(sizeof(*peer)); + peer->sock_fd = newfd; + + /* get an unused peer id */ + while (ivshmem_server_search_peer(server, server->cur_id) != NULL) { + server->cur_id++; + } + peer->id = server->cur_id++; + + /* create eventfd, one per vector */ + peer->vectors_count = server->n_vectors; + for (i = 0; i < peer->vectors_count; i++) { + if (event_notifier_init(&peer->vectors[i], FALSE) < 0) { + IVSHMEM_SERVER_DEBUG(server, "cannot create eventfd\n"); + goto fail; + } + } + + /* send peer id and shm fd */ + if (ivshmem_server_send_initial_info(server, peer) < 0) { + IVSHMEM_SERVER_DEBUG(server, "cannot send initial info\n"); + goto fail; + } + + /* advertise the new peer to others */ + QTAILQ_FOREACH(other_peer, &server->peer_list, next) { + for (i = 0; i < peer->vectors_count; i++) { + ivshmem_server_send_one_msg(other_peer->sock_fd, peer->id, + peer->vectors[i].wfd); + } + } + + /* advertise the other peers to the new one */ + QTAILQ_FOREACH(other_peer, &server->peer_list, next) { + for (i = 0; i < peer->vectors_count; i++) { + ivshmem_server_send_one_msg(peer->sock_fd, other_peer->id, + other_peer->vectors[i].wfd); + } + } + + /* advertise the new peer to itself */ + for (i = 0; i < peer->vectors_count; i++) { + ivshmem_server_send_one_msg(peer->sock_fd, peer->id, + event_notifier_get_fd(&peer->vectors[i])); + } + + QTAILQ_INSERT_TAIL(&server->peer_list, peer, next); + IVSHMEM_SERVER_DEBUG(server, "new peer id = %ld\n", + peer->id); + return 0; + +fail: + while (i--) { + event_notifier_cleanup(&peer->vectors[i]); + } + close(newfd); + g_free(peer); + return -1; +} + +/* Try to ftruncate a file to next power of 2 of shmsize. + * If it fails; all power of 2 above shmsize are tested until + * we reach the maximum huge page size. This is useful + * if the shm file is in a hugetlbfs that cannot be truncated to the + * shm_size value. */ +static int +ivshmem_server_ftruncate(int fd, unsigned shmsize) +{ + int ret; + struct stat mapstat; + + /* align shmsize to next power of 2 */ + shmsize = pow2ceil(shmsize); + + if (fstat(fd, &mapstat) != -1 && mapstat.st_size == shmsize) { + return 0; + } + + while (shmsize <= IVSHMEM_SERVER_MAX_HUGEPAGE_SIZE) { + ret = ftruncate(fd, shmsize); + if (ret == 0) { + return ret; + } + shmsize *= 2; + } + + return -1; +} + +/* Init a new ivshmem server */ +int +ivshmem_server_init(IvshmemServer *server, const char *unix_sock_path, + const char *shm_path, size_t shm_size, unsigned n_vectors, + bool verbose) +{ + int ret; + + memset(server, 0, sizeof(*server)); + server->verbose = verbose; + + ret = snprintf(server->unix_sock_path, sizeof(server->unix_sock_path), + "%s", unix_sock_path); + if (ret < 0 || ret >= sizeof(server->unix_sock_path)) { + IVSHMEM_SERVER_DEBUG(server, "could not copy unix socket path\n"); + return -1; + } + ret = snprintf(server->shm_path, sizeof(server->shm_path), + "%s", shm_path); + if (ret < 0 || ret >= sizeof(server->shm_path)) { + IVSHMEM_SERVER_DEBUG(server, "could not copy shm path\n"); + return -1; + } + + server->shm_size = shm_size; + server->n_vectors = n_vectors; + + QTAILQ_INIT(&server->peer_list); + + return 0; +} + +/* open shm, create and bind to the unix socket */ +int +ivshmem_server_start(IvshmemServer *server) +{ + struct sockaddr_un sun; + int shm_fd, sock_fd, ret; + + /* open shm file */ + shm_fd = shm_open(server->shm_path, O_CREAT|O_RDWR, S_IRWXU); + if (shm_fd < 0) { + fprintf(stderr, "cannot open shm file %s: %s\n", server->shm_path, + strerror(errno)); + return -1; + } + if (ivshmem_server_ftruncate(shm_fd, server->shm_size) < 0) { + fprintf(stderr, "ftruncate(%s) failed: %s\n", server->shm_path, + strerror(errno)); + goto err_close_shm; + } + + IVSHMEM_SERVER_DEBUG(server, "create & bind socket %s\n", + server->unix_sock_path); + + /* create the unix listening socket */ + sock_fd = socket(AF_UNIX, SOCK_STREAM, 0); + if (sock_fd < 0) { + IVSHMEM_SERVER_DEBUG(server, "cannot create socket: %s\n", + strerror(errno)); + goto err_close_shm; + } + + sun.sun_family = AF_UNIX; + ret = snprintf(sun.sun_path, sizeof(sun.sun_path), "%s", + server->unix_sock_path); + if (ret < 0 || ret >= sizeof(sun.sun_path)) { + IVSHMEM_SERVER_DEBUG(server, "could not copy unix socket path\n"); + goto err_close_sock; + } + if (bind(sock_fd, (struct sockaddr *)&sun, sizeof(sun)) < 0) { + IVSHMEM_SERVER_DEBUG(server, "cannot connect to %s: %s\n", sun.sun_path, + strerror(errno)); + goto err_close_sock; + } + + if (listen(sock_fd, IVSHMEM_SERVER_LISTEN_BACKLOG) < 0) { + IVSHMEM_SERVER_DEBUG(server, "listen() failed: %s\n", strerror(errno)); + goto err_close_sock; + } + + server->sock_fd = sock_fd; + server->shm_fd = shm_fd; + + return 0; + +err_close_sock: + close(sock_fd); +err_close_shm: + close(shm_fd); + return -1; +} + +/* close connections to clients, the unix socket and the shm fd */ +void +ivshmem_server_close(IvshmemServer *server) +{ + IvshmemServerPeer *peer, *npeer; + + IVSHMEM_SERVER_DEBUG(server, "close server\n"); + + QTAILQ_FOREACH_SAFE(peer, &server->peer_list, next, npeer) { + ivshmem_server_free_peer(server, peer); + } + + unlink(server->unix_sock_path); + close(server->sock_fd); + close(server->shm_fd); + server->sock_fd = -1; + server->shm_fd = -1; +} + +/* get the fd_set according to the unix socket and the peer list */ +void +ivshmem_server_get_fds(const IvshmemServer *server, fd_set *fds, int *maxfd) +{ + IvshmemServerPeer *peer; + + if (server->sock_fd == -1) { + return; + } + + FD_SET(server->sock_fd, fds); + if (server->sock_fd >= *maxfd) { + *maxfd = server->sock_fd + 1; + } + + QTAILQ_FOREACH(peer, &server->peer_list, next) { + FD_SET(peer->sock_fd, fds); + if (peer->sock_fd >= *maxfd) { + *maxfd = peer->sock_fd + 1; + } + } +} + +/* process incoming messages on the sockets in fd_set */ +int +ivshmem_server_handle_fds(IvshmemServer *server, fd_set *fds, int maxfd) +{ + IvshmemServerPeer *peer, *peer_next; + + if (server->sock_fd < maxfd && FD_ISSET(server->sock_fd, fds) && + ivshmem_server_handle_new_conn(server) < 0 && errno != EINTR) { + IVSHMEM_SERVER_DEBUG(server, "ivshmem_server_handle_new_conn() " + "failed\n"); + return -1; + } + + QTAILQ_FOREACH_SAFE(peer, &server->peer_list, next, peer_next) { + /* any message from a peer socket result in a close() */ + IVSHMEM_SERVER_DEBUG(server, "peer->sock_fd=%d\n", peer->sock_fd); + if (peer->sock_fd < maxfd && FD_ISSET(peer->sock_fd, fds)) { + ivshmem_server_free_peer(server, peer); + } + } + + return 0; +} + +/* lookup peer from its id */ +IvshmemServerPeer * +ivshmem_server_search_peer(IvshmemServer *server, long peer_id) +{ + IvshmemServerPeer *peer; + + QTAILQ_FOREACH(peer, &server->peer_list, next) { + if (peer->id == peer_id) { + return peer; + } + } + return NULL; +} + +/* dump our info, the list of peers their vectors on stdout */ +void +ivshmem_server_dump(const IvshmemServer *server) +{ + const IvshmemServerPeer *peer; + unsigned vector; + + /* dump peers */ + QTAILQ_FOREACH(peer, &server->peer_list, next) { + printf("peer_id = %ld\n", peer->id); + + for (vector = 0; vector < peer->vectors_count; vector++) { + printf(" vector %d is enabled (fd=%d)\n", vector, + event_notifier_get_fd(&peer->vectors[vector])); + } + } +} diff --git a/contrib/ivshmem-server/ivshmem-server.h b/contrib/ivshmem-server/ivshmem-server.h new file mode 100644 index 0000000000..bf7de7a7ca --- /dev/null +++ b/contrib/ivshmem-server/ivshmem-server.h @@ -0,0 +1,167 @@ +/* + * 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 <limits.h> +#include <sys/select.h> +#include <stdint.h> +#include <stdbool.h> + +#include "qemu/event_notifier.h" +#include "qemu/queue.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 */ + long 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 */ + size_t shm_size; /**< size of shm */ + int shm_fd; /**< shm file descriptor */ + unsigned n_vectors; /**< number of vectors */ + long 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. To use a real file, for instance in a hugetlbfs, + * it is possible to use /../../abspath/to/file. + * @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, 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, long 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_ */ diff --git a/contrib/ivshmem-server/main.c b/contrib/ivshmem-server/main.c new file mode 100644 index 0000000000..064de02277 --- /dev/null +++ b/contrib/ivshmem-server/main.c @@ -0,0 +1,264 @@ +/* + * 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. + */ + +#include "qemu-common.h" + +#include "ivshmem-server.h" + +#define IVSHMEM_SERVER_DEFAULT_VERBOSE 0 +#define IVSHMEM_SERVER_DEFAULT_FOREGROUND 0 +#define IVSHMEM_SERVER_DEFAULT_PID_FILE "/var/run/ivshmem-server.pid" +#define IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "/tmp/ivshmem_socket" +#define IVSHMEM_SERVER_DEFAULT_SHM_PATH "ivshmem" +#define IVSHMEM_SERVER_DEFAULT_SHM_SIZE (4*1024*1024) +#define IVSHMEM_SERVER_DEFAULT_N_VECTORS 1 + +/* used to quit on signal SIGTERM */ +static int ivshmem_server_quit; + +/* arguments given by the user */ +typedef struct IvshmemServerArgs { + bool verbose; + bool foreground; + const char *pid_file; + const char *unix_socket_path; + const char *shm_path; + uint64_t shm_size; + unsigned n_vectors; +} IvshmemServerArgs; + +/* show ivshmem_server_usage and exit with given error code */ +static void +ivshmem_server_usage(const char *name, int code) +{ + fprintf(stderr, "%s [opts]\n", name); + fprintf(stderr, " -h: show this help\n"); + fprintf(stderr, " -v: verbose mode\n"); + fprintf(stderr, " -F: foreground mode (default is to daemonize)\n"); + fprintf(stderr, " -p <pid_file>: path to the PID file (used in daemon\n" + " mode only).\n" + " Default=%s\n", IVSHMEM_SERVER_DEFAULT_SHM_PATH); + fprintf(stderr, " -S <unix_socket_path>: path to the unix socket\n" + " to listen to.\n" + " Default=%s\n", IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH); + fprintf(stderr, " -m <shm_path>: path to the shared memory.\n" + " The path corresponds to a POSIX shm name. To use a\n" + " real file, for instance in a hugetlbfs, use\n" + " /../../abspath/to/file.\n" + " default=%s\n", IVSHMEM_SERVER_DEFAULT_SHM_PATH); + fprintf(stderr, " -l <size>: size of shared memory in bytes. The suffix\n" + " K, M and G can be used (ex: 1K means 1024).\n" + " default=%u\n", IVSHMEM_SERVER_DEFAULT_SHM_SIZE); + fprintf(stderr, " -n <n_vects>: number of vectors.\n" + " default=%u\n", IVSHMEM_SERVER_DEFAULT_N_VECTORS); + + exit(code); +} + +/* parse the program arguments, exit on error */ +static void +ivshmem_server_parse_args(IvshmemServerArgs *args, int argc, char *argv[]) +{ + int c; + unsigned long long v; + Error *errp = NULL; + + while ((c = getopt(argc, argv, + "h" /* help */ + "v" /* verbose */ + "F" /* foreground */ + "p:" /* pid_file */ + "S:" /* unix_socket_path */ + "m:" /* shm_path */ + "l:" /* shm_size */ + "n:" /* n_vectors */ + )) != -1) { + + switch (c) { + case 'h': /* help */ + ivshmem_server_usage(argv[0], 0); + break; + + case 'v': /* verbose */ + args->verbose = 1; + break; + + case 'F': /* foreground */ + args->foreground = 1; + break; + + case 'p': /* pid_file */ + args->pid_file = strdup(optarg); + break; + + case 'S': /* unix_socket_path */ + args->unix_socket_path = strdup(optarg); + break; + + case 'm': /* shm_path */ + args->shm_path = strdup(optarg); + break; + + case 'l': /* shm_size */ + parse_option_size("shm_size", optarg, &args->shm_size, &errp); + if (errp) { + fprintf(stderr, "cannot parse shm size: %s\n", + error_get_pretty(errp)); + error_free(errp); + ivshmem_server_usage(argv[0], 1); + } + break; + + case 'n': /* n_vectors */ + if (parse_uint_full(optarg, &v, 0) < 0) { + fprintf(stderr, "cannot parse n_vectors\n"); + ivshmem_server_usage(argv[0], 1); + } + args->n_vectors = v; + break; + + default: + ivshmem_server_usage(argv[0], 1); + break; + } + } + + if (args->n_vectors > IVSHMEM_SERVER_MAX_VECTORS) { + fprintf(stderr, "too many requested vectors (max is %d)\n", + IVSHMEM_SERVER_MAX_VECTORS); + ivshmem_server_usage(argv[0], 1); + } + + if (args->verbose == 1 && args->foreground == 0) { + fprintf(stderr, "cannot use verbose in daemon mode\n"); + ivshmem_server_usage(argv[0], 1); + } +} + +/* wait for events on listening server unix socket and connected client + * sockets */ +static int +ivshmem_server_poll_events(IvshmemServer *server) +{ + fd_set fds; + int ret = 0, maxfd; + + while (!ivshmem_server_quit) { + + FD_ZERO(&fds); + maxfd = 0; + ivshmem_server_get_fds(server, &fds, &maxfd); + + ret = select(maxfd, &fds, NULL, NULL, NULL); + + if (ret < 0) { + if (errno == EINTR) { + continue; + } + + fprintf(stderr, "select error: %s\n", strerror(errno)); + break; + } + if (ret == 0) { + continue; + } + + if (ivshmem_server_handle_fds(server, &fds, maxfd) < 0) { + fprintf(stderr, "ivshmem_server_handle_fds() failed\n"); + break; + } + } + + return ret; +} + +static void +ivshmem_server_quit_cb(int signum) +{ + ivshmem_server_quit = 1; +} + +int +main(int argc, char *argv[]) +{ + IvshmemServer server; + struct sigaction sa, sa_quit; + IvshmemServerArgs args = { + .verbose = IVSHMEM_SERVER_DEFAULT_VERBOSE, + .foreground = IVSHMEM_SERVER_DEFAULT_FOREGROUND, + .pid_file = IVSHMEM_SERVER_DEFAULT_PID_FILE, + .unix_socket_path = IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH, + .shm_path = IVSHMEM_SERVER_DEFAULT_SHM_PATH, + .shm_size = IVSHMEM_SERVER_DEFAULT_SHM_SIZE, + .n_vectors = IVSHMEM_SERVER_DEFAULT_N_VECTORS, + }; + int ret = 1; + + /* parse arguments, will exit on error */ + ivshmem_server_parse_args(&args, argc, argv); + + /* Ignore SIGPIPE, see this link for more info: + * http://www.mail-archive.com/libevent-users@monkey.org/msg01606.html */ + sa.sa_handler = SIG_IGN; + sa.sa_flags = 0; + if (sigemptyset(&sa.sa_mask) == -1 || + sigaction(SIGPIPE, &sa, 0) == -1) { + perror("failed to ignore SIGPIPE; sigaction"); + goto err; + } + + sa_quit.sa_handler = ivshmem_server_quit_cb; + sa_quit.sa_flags = 0; + if (sigemptyset(&sa_quit.sa_mask) == -1 || + sigaction(SIGTERM, &sa_quit, 0) == -1) { + perror("failed to add SIGTERM handler; sigaction"); + goto err; + } + + /* init the ivshms structure */ + if (ivshmem_server_init(&server, args.unix_socket_path, args.shm_path, + args.shm_size, args.n_vectors, args.verbose) < 0) { + fprintf(stderr, "cannot init server\n"); + goto err; + } + + /* start the ivshmem server (open shm & unix socket) */ + if (ivshmem_server_start(&server) < 0) { + fprintf(stderr, "cannot bind\n"); + goto err; + } + + /* daemonize if asked to */ + if (!args.foreground) { + FILE *fp; + + if (qemu_daemon(1, 1) < 0) { + fprintf(stderr, "cannot daemonize: %s\n", strerror(errno)); + goto err_close; + } + + /* write pid file */ + fp = fopen(args.pid_file, "w"); + if (fp == NULL) { + fprintf(stderr, "cannot write pid file: %s\n", strerror(errno)); + goto err_close; + } + + fprintf(fp, "%d\n", (int) getpid()); + fclose(fp); + } + + ivshmem_server_poll_events(&server); + fprintf(stdout, "server disconnected\n"); + ret = 0; + +err_close: + ivshmem_server_close(&server); +err: + return ret; +} diff --git a/qemu-doc.texi b/qemu-doc.texi index 5b81aa052d..afa226303b 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -1266,9 +1266,13 @@ is qemu.git/contrib/ivshmem-server. An example syntax when using the shared memory server is: @example -qemu-system-i386 -device ivshmem,size=<size in format accepted by -m>[,chardev=<id>] - [,msi=on][,ioeventfd=on][,vectors=n][,role=peer|master] -qemu-system-i386 -chardev socket,path=<path>,id=<id> +# First start the ivshmem server once and for all +ivshmem-server -p <pidfile> -S <path> -m <shm name> -l <shm size> -n <vectors n> + +# Then start your qemu instances with matching arguments +qemu-system-i386 -device ivshmem,size=<shm size>,vectors=<vectors n>,chardev=<id> + [,msi=on][,ioeventfd=on][,role=peer|master] + -chardev socket,path=<path>,id=<id> @end example When using the server, the guest will be assigned a VM ID (>=0) that allows guests |