| Message ID | 1acc31a0de7efc9d7c3bc6ca42b985a36e19c28c.1578407802.git.jan.kiszka@siemens.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | IVSHMEM version 2 device for QEMU | expand |
A quick check by checkpatch.pl, pretty straightforward to fix.
ERROR: memory barrier without comment
#205: FILE: contrib/ivshmem2-server/ivshmem2-server.c:106:
+ smp_mb();
ERROR: spaces required around that '*' (ctx:VxV)
#753: FILE: contrib/ivshmem2-server/main.c:22:
+#define IVSHMEM_SERVER_DEFAULT_SHM_SIZE (4*1024*1024)
^
ERROR: spaces required around that '*' (ctx:VxV)
#753: FILE: contrib/ivshmem2-server/main.c:22:
+#define IVSHMEM_SERVER_DEFAULT_SHM_SIZE (4*1024*1024)
Best,
Liang
On 1/7/20 9:36 AM, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
>
> This implements the server process for ivshmem v2 device models of QEMU.
> Again, no effort has been spent yet on sharing code with the v1 server.
> Parts have been copied, others were rewritten.
>
> In addition to parameters of v1, this server now also specifies
>
> - the maximum number of peers to be connected (required to know in
> advance because of v2's state table)
> - the size of the output sections (can be 0)
> - the protocol ID to be published to all peers
>
> When a virtio protocol ID is chosen, only 2 peers can be connected.
> Furthermore, the server will signal the backend variant of the ID to the
> master instance and the frontend ID to the slave peer.
>
> To start, e.g., a server that allows virtio console over ivshmem, call
>
> ivshmem2-server -F -l 64K -n 2 -V 3 -P 0x8003
>
> TODO: specify the new server protocol.
>
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
> Makefile | 3 +
> Makefile.objs | 1 +
> configure | 1 +
> contrib/ivshmem2-server/Makefile.objs | 1 +
> contrib/ivshmem2-server/ivshmem2-server.c | 462 ++++++++++++++++++++++++++++++
> contrib/ivshmem2-server/ivshmem2-server.h | 158 ++++++++++
> contrib/ivshmem2-server/main.c | 313 ++++++++++++++++++++
> 7 files changed, 939 insertions(+)
> create mode 100644 contrib/ivshmem2-server/Makefile.objs
> create mode 100644 contrib/ivshmem2-server/ivshmem2-server.c
> create mode 100644 contrib/ivshmem2-server/ivshmem2-server.h
> create mode 100644 contrib/ivshmem2-server/main.c
>
> diff --git a/Makefile b/Makefile
> index 6b5ad1121b..33bb0eefdb 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -427,6 +427,7 @@ dummy := $(call unnest-vars,, \
> elf2dmp-obj-y \
> ivshmem-client-obj-y \
> ivshmem-server-obj-y \
> + ivshmem2-server-obj-y \
> rdmacm-mux-obj-y \
> libvhost-user-obj-y \
> vhost-user-scsi-obj-y \
> @@ -655,6 +656,8 @@ ivshmem-client$(EXESUF): $(ivshmem-client-obj-y) $(COMMON_LDADDS)
> $(call LINK, $^)
> ivshmem-server$(EXESUF): $(ivshmem-server-obj-y) $(COMMON_LDADDS)
> $(call LINK, $^)
> +ivshmem2-server$(EXESUF): $(ivshmem2-server-obj-y) $(COMMON_LDADDS)
> + $(call LINK, $^)
> endif
> vhost-user-scsi$(EXESUF): $(vhost-user-scsi-obj-y) libvhost-user.a
> $(call LINK, $^)
> diff --git a/Makefile.objs b/Makefile.objs
> index 02bf5ce11d..ce243975ef 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -115,6 +115,7 @@ qga-vss-dll-obj-y = qga/
> elf2dmp-obj-y = contrib/elf2dmp/
> ivshmem-client-obj-$(CONFIG_IVSHMEM) = contrib/ivshmem-client/
> ivshmem-server-obj-$(CONFIG_IVSHMEM) = contrib/ivshmem-server/
> +ivshmem2-server-obj-$(CONFIG_IVSHMEM) = contrib/ivshmem2-server/
> libvhost-user-obj-y = contrib/libvhost-user/
> vhost-user-scsi.o-cflags := $(LIBISCSI_CFLAGS)
> vhost-user-scsi.o-libs := $(LIBISCSI_LIBS)
> diff --git a/configure b/configure
> index 747d3b4120..1cb1427f1b 100755
> --- a/configure
> +++ b/configure
> @@ -6165,6 +6165,7 @@ if test "$want_tools" = "yes" ; then
> fi
> if [ "$ivshmem" = "yes" ]; then
> tools="ivshmem-client\$(EXESUF) ivshmem-server\$(EXESUF) $tools"
> + tools="ivshmem2-server\$(EXESUF) $tools"
> fi
> if [ "$curl" = "yes" ]; then
> tools="elf2dmp\$(EXESUF) $tools"
> diff --git a/contrib/ivshmem2-server/Makefile.objs b/contrib/ivshmem2-server/Makefile.objs
> new file mode 100644
> index 0000000000..d233e18ec8
> --- /dev/null
> +++ b/contrib/ivshmem2-server/Makefile.objs
> @@ -0,0 +1 @@
> +ivshmem2-server-obj-y = ivshmem2-server.o main.o
> diff --git a/contrib/ivshmem2-server/ivshmem2-server.c b/contrib/ivshmem2-server/ivshmem2-server.c
> new file mode 100644
> index 0000000000..b341f1fcd0
> --- /dev/null
> +++ b/contrib/ivshmem2-server/ivshmem2-server.c
> @@ -0,0 +1,462 @@
> +/*
> + * Copyright 6WIND S.A., 2014
> + * Copyright (c) Siemens AG, 2019
> + *
> + * 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/osdep.h"
> +#include "qemu/host-utils.h"
> +#include "qemu/sockets.h"
> +#include "qemu/atomic.h"
> +
> +#include <sys/socket.h>
> +#include <sys/un.h>
> +
> +#include "ivshmem2-server.h"
> +
> +/* log a message on stdout if verbose=1 */
> +#define IVSHMEM_SERVER_DEBUG(server, fmt, ...) do { \
> + if ((server)->args.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_msg(int sock_fd, void *payload, int len, 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 = payload;
> + iov[0].iov_len = len;
> +
> + 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;
> +}
> +
> +static int ivshmem_server_send_event_fd(int sock_fd, int peer_id, int vector,
> + int fd)
> +{
> + IvshmemEventFd msg = {
> + .header = {
> + .type = GUINT32_TO_LE(IVSHMEM_MSG_EVENT_FD),
> + .len = GUINT32_TO_LE(sizeof(msg)),
> + },
> + .id = GUINT32_TO_LE(peer_id),
> + .vector = GUINT32_TO_LE(vector),
> + };
> +
> + return ivshmem_server_send_msg(sock_fd, &msg, sizeof(msg), fd);
> +}
> +
> +/* 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;
> + IvshmemPeerGone msg = {
> + .header = {
> + .type = GUINT32_TO_LE(IVSHMEM_MSG_PEER_GONE),
> + .len = GUINT32_TO_LE(sizeof(msg)),
> + },
> + .id = GUINT32_TO_LE(peer->id),
> + };
> +
> + IVSHMEM_SERVER_DEBUG(server, "free peer %" PRId64 "\n", peer->id);
> + close(peer->sock_fd);
> + QTAILQ_REMOVE(&server->peer_list, peer, next);
> +
> + server->state_table[peer->id] = 0;
> + smp_mb();
> +
> + /* advertise the deletion to other peers */
> + QTAILQ_FOREACH(other_peer, &server->peer_list, next) {
> + ivshmem_server_send_msg(other_peer->sock_fd, &msg, sizeof(msg), -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)
> +{
> + IvshmemInitialInfo msg = {
> + .header = {
> + .type = GUINT32_TO_LE(IVSHMEM_MSG_INIT),
> + .len = GUINT32_TO_LE(sizeof(msg)),
> + },
> + .version = GUINT32_TO_LE(IVSHMEM_PROTOCOL_VERSION),
> + .compatible_version = GUINT32_TO_LE(IVSHMEM_PROTOCOL_VERSION),
> + .id = GUINT32_TO_LE(peer->id),
> + .max_peers = GUINT32_TO_LE(server->args.max_peers),
> + .vectors = GUINT32_TO_LE(server->args.vectors),
> + .protocol = GUINT32_TO_LE(server->args.protocol),
> + .output_section_size = GUINT64_TO_LE(server->args.output_section_size),
> + };
> + unsigned virtio_protocol;
> + int ret;
> +
> + if (server->args.protocol >= 0x8000) {
> + virtio_protocol = server->args.protocol & ~0x4000;
> + msg.protocol &= ~0x4000;
> + if (peer->id == 0) {
> + virtio_protocol |= 0x4000;
> + }
> + msg.protocol = GUINT32_TO_LE(virtio_protocol);
> + }
> +
> + ret = ivshmem_server_send_msg(peer->sock_fd, &msg, sizeof(msg),
> + server->shm_fd);
> + if (ret < 0) {
> + IVSHMEM_SERVER_DEBUG(server, "cannot send initial info: %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 */
> + /* XXX: this could use id allocation such as Linux IDA, or simply
> + * a free-list */
> + for (i = 0; i < G_MAXUINT16; i++) {
> + if (ivshmem_server_search_peer(server, i) == NULL) {
> + break;
> + }
> + }
> + if (i >= server->args.max_peers) {
> + IVSHMEM_SERVER_DEBUG(server, "cannot allocate new client id\n");
> + close(newfd);
> + g_free(peer);
> + return -1;
> + }
> + peer->id = i;
> +
> + /* create eventfd, one per vector */
> + peer->vectors_count = server->args.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_event_fd(other_peer->sock_fd, peer->id, i,
> + 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_event_fd(peer->sock_fd, other_peer->id, i,
> + other_peer->vectors[i].wfd);
> + }
> + }
> +
> + /* advertise the new peer to itself */
> + for (i = 0; i < peer->vectors_count; i++) {
> + ivshmem_server_send_event_fd(peer->sock_fd, peer->id, i,
> + event_notifier_get_fd(&peer->vectors[i]));
> + }
> +
> + QTAILQ_INSERT_TAIL(&server->peer_list, peer, next);
> + IVSHMEM_SERVER_DEBUG(server, "new peer id = %" PRId64 "\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 */
> +void ivshmem_server_init(IvshmemServer *server)
> +{
> + server->sock_fd = -1;
> + server->shm_fd = -1;
> + server->state_table = NULL;
> + QTAILQ_INIT(&server->peer_list);
> +}
> +
> +/* 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;
> + void *state_table;
> +
> + /* open shm file */
> + if (server->args.use_shm_open) {
> + IVSHMEM_SERVER_DEBUG(server, "Using POSIX shared memory: %s\n",
> + server->args.shm_path);
> + shm_fd = shm_open(server->args.shm_path, O_CREAT | O_RDWR, S_IRWXU);
> + } else {
> + gchar *filename = g_strdup_printf("%s/ivshmem.XXXXXX",
> + server->args.shm_path);
> + IVSHMEM_SERVER_DEBUG(server, "Using file-backed shared memory: %s\n",
> + server->args.shm_path);
> + shm_fd = mkstemp(filename);
> + unlink(filename);
> + g_free(filename);
> + }
> +
> + if (shm_fd < 0) {
> + fprintf(stderr, "cannot open shm file %s: %s\n", server->args.shm_path,
> + strerror(errno));
> + return -1;
> + }
> + if (ivshmem_server_ftruncate(shm_fd, server->args.shm_size) < 0) {
> + fprintf(stderr, "ftruncate(%s) failed: %s\n", server->args.shm_path,
> + strerror(errno));
> + goto err_close_shm;
> + }
> + state_table = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED,
> + shm_fd, 0);
> + if (state_table == MAP_FAILED) {
> + fprintf(stderr, "mmap failed: %s\n", strerror(errno));
> + goto err_close_shm;
> + }
> +
> + IVSHMEM_SERVER_DEBUG(server, "create & bind socket %s\n",
> + server->args.unix_socket_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_unmap;
> + }
> +
> + sun.sun_family = AF_UNIX;
> + ret = snprintf(sun.sun_path, sizeof(sun.sun_path), "%s",
> + server->args.unix_socket_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;
> + server->state_table = state_table;
> +
> + return 0;
> +
> +err_close_sock:
> + close(sock_fd);
> +err_unmap:
> + munmap(state_table, 4096);
> +err_close_shm:
> + if (server->args.use_shm_open) {
> + shm_unlink(server->args.shm_path);
> + }
> + close(shm_fd);
> + shm_unlink(server->args.shm_path);
> + 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->args.unix_socket_path);
> + if (server->args.use_shm_open) {
> + shm_unlink(server->args.shm_path);
> + }
> + close(server->sock_fd);
> + munmap(server->state_table, 4096);
> + 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, int64_t peer_id)
> +{
> + IvshmemServerPeer *peer;
> +
> + QTAILQ_FOREACH(peer, &server->peer_list, next) {
> + if (peer->id == peer_id) {
> + return peer;
> + }
> + }
> + return NULL;
> +}
> diff --git a/contrib/ivshmem2-server/ivshmem2-server.h b/contrib/ivshmem2-server/ivshmem2-server.h
> new file mode 100644
> index 0000000000..3fd6166577
> --- /dev/null
> +++ b/contrib/ivshmem2-server/ivshmem2-server.h
> @@ -0,0 +1,158 @@
> +/*
> + * Copyright 6WIND S.A., 2014
> + * Copyright (c) Siemens AG, 2019
> + *
> + * 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 IVSHMEM2_SERVER_H
> +#define IVSHMEM2_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 being
> + * "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/ivshmem2.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;
> +
> +/**
> + * Structure describing ivshmem server arguments
> + */
> +typedef struct IvshmemServerArgs {
> + bool verbose; /**< true to enable verbose mode */
> + const char *unix_socket_path; /**< pointer to unix socket file name */
> + const char *shm_path; /**< Path to the shared memory; path
> + corresponds to a POSIX shm name or a
> + hugetlbfs mount point. */
> + bool use_shm_open; /**< true to use shm_open, false for
> + file-backed shared memory */
> + uint64_t shm_size; /**< total size of shared memory */
> + uint64_t output_section_size; /**< size of each output section */
> + unsigned max_peers; /**< maximum number of peers */
> + unsigned vectors; /**< interrupt vectors per client */
> + unsigned protocol; /**< protocol advertised to all clients */
> +} IvshmemServerArgs;
> +
> +/**
> + * 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 {
> + IvshmemServerArgs args; /**< server arguments */
> + int sock_fd; /**< unix sock file descriptor */
> + int shm_fd; /**< shm file descriptor */
> + uint32_t *state_table; /**< mapped state table */
> + QTAILQ_HEAD(, IvshmemServerPeer) peer_list; /**< list of peers */
> +} IvshmemServer;
> +
> +/**
> + * Initialize an ivshmem server
> + *
> + * @server: A pointer to an uninitialized IvshmemServer structure
> + */
> +void ivshmem_server_init(IvshmemServer *server);
> +
> +/**
> + * 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);
> +
> +#endif /* IVSHMEM2_SERVER_H */
> diff --git a/contrib/ivshmem2-server/main.c b/contrib/ivshmem2-server/main.c
> new file mode 100644
> index 0000000000..35cd6fca0f
> --- /dev/null
> +++ b/contrib/ivshmem2-server/main.c
> @@ -0,0 +1,313 @@
> +/*
> + * Copyright 6WIND S.A., 2014
> + * Copyright (c) Siemens AG, 2019
> + *
> + * 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/osdep.h"
> +#include "qapi/error.h"
> +#include "qemu/cutils.h"
> +#include "qemu/option.h"
> +#include "ivshmem2-server.h"
> +
> +#define IVSHMEM_SERVER_DEFAULT_FOREGROUND 0
> +#define IVSHMEM_SERVER_DEFAULT_PID_FILE "/var/run/ivshmem-server.pid"
> +
> +#define IVSHMEM_SERVER_DEFAULT_VERBOSE 0
> +#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_OUTPUT_SEC_SZ 0
> +#define IVSHMEM_SERVER_DEFAULT_MAX_PEERS 2
> +#define IVSHMEM_SERVER_DEFAULT_VECTORS 1
> +#define IVSHMEM_SERVER_DEFAULT_PROTOCOL 0
> +
> +/* used to quit on signal SIGTERM */
> +static int ivshmem_server_quit;
> +
> +static bool foreground = IVSHMEM_SERVER_DEFAULT_FOREGROUND;
> +static const char *pid_file = IVSHMEM_SERVER_DEFAULT_PID_FILE;
> +
> +static void
> +ivshmem_server_usage(const char *progname)
> +{
> + printf("Usage: %s [OPTION]...\n"
> + " -h: show this help\n"
> + " -v: verbose mode\n"
> + " -F: foreground mode (default is to daemonize)\n"
> + " -p <pid-file>: path to the PID file (used in daemon mode only)\n"
> + " default " IVSHMEM_SERVER_DEFAULT_PID_FILE "\n"
> + " -S <unix-socket-path>: path to the unix socket to listen to\n"
> + " default " IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "\n"
> + " -M <shm-name>: POSIX shared memory object to use\n"
> + " default " IVSHMEM_SERVER_DEFAULT_SHM_PATH "\n"
> + " -m <dir-name>: where to create shared memory\n"
> + " -l <size>: size of shared memory in bytes\n"
> + " suffixes K, M and G can be used, e.g. 1K means 1024\n"
> + " default %u\n"
> + " -o <size>: size of each output section in bytes "
> + "(suffixes supported)\n"
> + " default %u\n"
> + " -n <peers>: maximum number of peers\n"
> + " default %u\n"
> + " -V <vectors>: number of vectors\n"
> + " default %u\n"
> + " -P <protocol>: 16-bit protocol to be advertised\n"
> + " default 0x%04x\n"
> + " When using virtio (0x8000...0xffff), only two peers are "
> + "supported, peer 0\n"
> + " will become backend, peer 1 frontend\n",
> + progname, IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
> + IVSHMEM_SERVER_DEFAULT_OUTPUT_SEC_SZ,
> + IVSHMEM_SERVER_DEFAULT_MAX_PEERS, IVSHMEM_SERVER_DEFAULT_VECTORS,
> + IVSHMEM_SERVER_DEFAULT_PROTOCOL);
> +}
> +
> +static void
> +ivshmem_server_help(const char *progname)
> +{
> + fprintf(stderr, "Try '%s -h' for more information.\n", progname);
> +}
> +
> +/* 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 *err = NULL;
> +
> + while ((c = getopt(argc, argv, "hvFp:S:m:M:l:o:n:V:P:")) != -1) {
> +
> + switch (c) {
> + case 'h': /* help */
> + ivshmem_server_usage(argv[0]);
> + exit(0);
> + break;
> +
> + case 'v': /* verbose */
> + args->verbose = 1;
> + break;
> +
> + case 'F': /* foreground */
> + foreground = 1;
> + break;
> +
> + case 'p': /* pid file */
> + pid_file = optarg;
> + break;
> +
> + case 'S': /* unix socket path */
> + args->unix_socket_path = optarg;
> + break;
> +
> + case 'M': /* shm name */
> + case 'm': /* dir name */
> + args->shm_path = optarg;
> + args->use_shm_open = c == 'M';
> + break;
> +
> + case 'l': /* shm size */
> + parse_option_size("shm_size", optarg, &args->shm_size, &err);
> + if (err) {
> + error_report_err(err);
> + ivshmem_server_help(argv[0]);
> + exit(1);
> + }
> + break;
> +
> + case 'o': /* output section size */
> + parse_option_size("output_section_size", optarg,
> + &args->output_section_size, &err);
> + if (err) {
> + error_report_err(err);
> + ivshmem_server_help(argv[0]);
> + exit(1);
> + }
> + break;
> +
> + case 'n': /* maximum number of peers */
> + if (parse_uint_full(optarg, &v, 0) < 0) {
> + fprintf(stderr, "cannot parse max-peers\n");
> + ivshmem_server_help(argv[0]);
> + exit(1);
> + }
> + args->max_peers = v;
> + break;
> +
> + case 'V': /* number of vectors */
> + if (parse_uint_full(optarg, &v, 0) < 0) {
> + fprintf(stderr, "cannot parse vectors\n");
> + ivshmem_server_help(argv[0]);
> + exit(1);
> + }
> + args->vectors = v;
> + break;
> +
> + case 'P': /* protocol */
> + if (parse_uint_full(optarg, &v, 0) < 0) {
> + fprintf(stderr, "cannot parse protocol\n");
> + ivshmem_server_help(argv[0]);
> + exit(1);
> + }
> + args->protocol = v;
> + break;
> +
> + default:
> + ivshmem_server_usage(argv[0]);
> + exit(1);
> + break;
> + }
> + }
> +
> + if (args->vectors > IVSHMEM_SERVER_MAX_VECTORS) {
> + fprintf(stderr, "too many requested vectors (max is %d)\n",
> + IVSHMEM_SERVER_MAX_VECTORS);
> + ivshmem_server_help(argv[0]);
> + exit(1);
> + }
> +
> + if (args->protocol >= 0x8000 && args->max_peers > 2) {
> + fprintf(stderr, "virtio protocols only support 2 peers\n");
> + ivshmem_server_help(argv[0]);
> + exit(1);
> + }
> +
> + if (args->verbose == 1 && foreground == 0) {
> + fprintf(stderr, "cannot use verbose in daemon mode\n");
> + ivshmem_server_help(argv[0]);
> + exit(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 = {
> + .args = {
> + .verbose = IVSHMEM_SERVER_DEFAULT_VERBOSE,
> + .unix_socket_path = IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH,
> + .shm_path = IVSHMEM_SERVER_DEFAULT_SHM_PATH,
> + .use_shm_open = true,
> + .shm_size = IVSHMEM_SERVER_DEFAULT_SHM_SIZE,
> + .output_section_size = IVSHMEM_SERVER_DEFAULT_OUTPUT_SEC_SZ,
> + .max_peers = IVSHMEM_SERVER_DEFAULT_MAX_PEERS,
> + .vectors = IVSHMEM_SERVER_DEFAULT_VECTORS,
> + .protocol = IVSHMEM_SERVER_DEFAULT_PROTOCOL,
> + },
> + };
> + struct sigaction sa, sa_quit;
> + int ret = 1;
> +
> + /*
> + * Do not remove this notice without adding proper error handling!
> + * Start with handling ivshmem_server_send_one_msg() failure.
> + */
> + printf("*** Example code, do not use in production ***\n");
> +
> + /* parse arguments, will exit on error */
> + ivshmem_server_parse_args(&server.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 ||
> + sigaction(SIGINT, &sa_quit, 0) == -1) {
> + perror("failed to add signal handler; sigaction");
> + goto err;
> + }
> +
> + /* init the ivshms structure */
> + ivshmem_server_init(&server);
> +
> + /* 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 (!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(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/Makefile b/Makefile index 6b5ad1121b..33bb0eefdb 100644 --- a/Makefile +++ b/Makefile @@ -427,6 +427,7 @@ dummy := $(call unnest-vars,, \ elf2dmp-obj-y \ ivshmem-client-obj-y \ ivshmem-server-obj-y \ + ivshmem2-server-obj-y \ rdmacm-mux-obj-y \ libvhost-user-obj-y \ vhost-user-scsi-obj-y \ @@ -655,6 +656,8 @@ ivshmem-client$(EXESUF): $(ivshmem-client-obj-y) $(COMMON_LDADDS) $(call LINK, $^) ivshmem-server$(EXESUF): $(ivshmem-server-obj-y) $(COMMON_LDADDS) $(call LINK, $^) +ivshmem2-server$(EXESUF): $(ivshmem2-server-obj-y) $(COMMON_LDADDS) + $(call LINK, $^) endif vhost-user-scsi$(EXESUF): $(vhost-user-scsi-obj-y) libvhost-user.a $(call LINK, $^) diff --git a/Makefile.objs b/Makefile.objs index 02bf5ce11d..ce243975ef 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -115,6 +115,7 @@ qga-vss-dll-obj-y = qga/ elf2dmp-obj-y = contrib/elf2dmp/ ivshmem-client-obj-$(CONFIG_IVSHMEM) = contrib/ivshmem-client/ ivshmem-server-obj-$(CONFIG_IVSHMEM) = contrib/ivshmem-server/ +ivshmem2-server-obj-$(CONFIG_IVSHMEM) = contrib/ivshmem2-server/ libvhost-user-obj-y = contrib/libvhost-user/ vhost-user-scsi.o-cflags := $(LIBISCSI_CFLAGS) vhost-user-scsi.o-libs := $(LIBISCSI_LIBS) diff --git a/configure b/configure index 747d3b4120..1cb1427f1b 100755 --- a/configure +++ b/configure @@ -6165,6 +6165,7 @@ if test "$want_tools" = "yes" ; then fi if [ "$ivshmem" = "yes" ]; then tools="ivshmem-client\$(EXESUF) ivshmem-server\$(EXESUF) $tools" + tools="ivshmem2-server\$(EXESUF) $tools" fi if [ "$curl" = "yes" ]; then tools="elf2dmp\$(EXESUF) $tools" diff --git a/contrib/ivshmem2-server/Makefile.objs b/contrib/ivshmem2-server/Makefile.objs new file mode 100644 index 0000000000..d233e18ec8 --- /dev/null +++ b/contrib/ivshmem2-server/Makefile.objs @@ -0,0 +1 @@ +ivshmem2-server-obj-y = ivshmem2-server.o main.o diff --git a/contrib/ivshmem2-server/ivshmem2-server.c b/contrib/ivshmem2-server/ivshmem2-server.c new file mode 100644 index 0000000000..b341f1fcd0 --- /dev/null +++ b/contrib/ivshmem2-server/ivshmem2-server.c @@ -0,0 +1,462 @@ +/* + * Copyright 6WIND S.A., 2014 + * Copyright (c) Siemens AG, 2019 + * + * 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/osdep.h" +#include "qemu/host-utils.h" +#include "qemu/sockets.h" +#include "qemu/atomic.h" + +#include <sys/socket.h> +#include <sys/un.h> + +#include "ivshmem2-server.h" + +/* log a message on stdout if verbose=1 */ +#define IVSHMEM_SERVER_DEBUG(server, fmt, ...) do { \ + if ((server)->args.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_msg(int sock_fd, void *payload, int len, 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 = payload; + iov[0].iov_len = len; + + 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; +} + +static int ivshmem_server_send_event_fd(int sock_fd, int peer_id, int vector, + int fd) +{ + IvshmemEventFd msg = { + .header = { + .type = GUINT32_TO_LE(IVSHMEM_MSG_EVENT_FD), + .len = GUINT32_TO_LE(sizeof(msg)), + }, + .id = GUINT32_TO_LE(peer_id), + .vector = GUINT32_TO_LE(vector), + }; + + return ivshmem_server_send_msg(sock_fd, &msg, sizeof(msg), fd); +} + +/* 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; + IvshmemPeerGone msg = { + .header = { + .type = GUINT32_TO_LE(IVSHMEM_MSG_PEER_GONE), + .len = GUINT32_TO_LE(sizeof(msg)), + }, + .id = GUINT32_TO_LE(peer->id), + }; + + IVSHMEM_SERVER_DEBUG(server, "free peer %" PRId64 "\n", peer->id); + close(peer->sock_fd); + QTAILQ_REMOVE(&server->peer_list, peer, next); + + server->state_table[peer->id] = 0; + smp_mb(); + + /* advertise the deletion to other peers */ + QTAILQ_FOREACH(other_peer, &server->peer_list, next) { + ivshmem_server_send_msg(other_peer->sock_fd, &msg, sizeof(msg), -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) +{ + IvshmemInitialInfo msg = { + .header = { + .type = GUINT32_TO_LE(IVSHMEM_MSG_INIT), + .len = GUINT32_TO_LE(sizeof(msg)), + }, + .version = GUINT32_TO_LE(IVSHMEM_PROTOCOL_VERSION), + .compatible_version = GUINT32_TO_LE(IVSHMEM_PROTOCOL_VERSION), + .id = GUINT32_TO_LE(peer->id), + .max_peers = GUINT32_TO_LE(server->args.max_peers), + .vectors = GUINT32_TO_LE(server->args.vectors), + .protocol = GUINT32_TO_LE(server->args.protocol), + .output_section_size = GUINT64_TO_LE(server->args.output_section_size), + }; + unsigned virtio_protocol; + int ret; + + if (server->args.protocol >= 0x8000) { + virtio_protocol = server->args.protocol & ~0x4000; + msg.protocol &= ~0x4000; + if (peer->id == 0) { + virtio_protocol |= 0x4000; + } + msg.protocol = GUINT32_TO_LE(virtio_protocol); + } + + ret = ivshmem_server_send_msg(peer->sock_fd, &msg, sizeof(msg), + server->shm_fd); + if (ret < 0) { + IVSHMEM_SERVER_DEBUG(server, "cannot send initial info: %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 */ + /* XXX: this could use id allocation such as Linux IDA, or simply + * a free-list */ + for (i = 0; i < G_MAXUINT16; i++) { + if (ivshmem_server_search_peer(server, i) == NULL) { + break; + } + } + if (i >= server->args.max_peers) { + IVSHMEM_SERVER_DEBUG(server, "cannot allocate new client id\n"); + close(newfd); + g_free(peer); + return -1; + } + peer->id = i; + + /* create eventfd, one per vector */ + peer->vectors_count = server->args.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_event_fd(other_peer->sock_fd, peer->id, i, + 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_event_fd(peer->sock_fd, other_peer->id, i, + other_peer->vectors[i].wfd); + } + } + + /* advertise the new peer to itself */ + for (i = 0; i < peer->vectors_count; i++) { + ivshmem_server_send_event_fd(peer->sock_fd, peer->id, i, + event_notifier_get_fd(&peer->vectors[i])); + } + + QTAILQ_INSERT_TAIL(&server->peer_list, peer, next); + IVSHMEM_SERVER_DEBUG(server, "new peer id = %" PRId64 "\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 */ +void ivshmem_server_init(IvshmemServer *server) +{ + server->sock_fd = -1; + server->shm_fd = -1; + server->state_table = NULL; + QTAILQ_INIT(&server->peer_list); +} + +/* 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; + void *state_table; + + /* open shm file */ + if (server->args.use_shm_open) { + IVSHMEM_SERVER_DEBUG(server, "Using POSIX shared memory: %s\n", + server->args.shm_path); + shm_fd = shm_open(server->args.shm_path, O_CREAT | O_RDWR, S_IRWXU); + } else { + gchar *filename = g_strdup_printf("%s/ivshmem.XXXXXX", + server->args.shm_path); + IVSHMEM_SERVER_DEBUG(server, "Using file-backed shared memory: %s\n", + server->args.shm_path); + shm_fd = mkstemp(filename); + unlink(filename); + g_free(filename); + } + + if (shm_fd < 0) { + fprintf(stderr, "cannot open shm file %s: %s\n", server->args.shm_path, + strerror(errno)); + return -1; + } + if (ivshmem_server_ftruncate(shm_fd, server->args.shm_size) < 0) { + fprintf(stderr, "ftruncate(%s) failed: %s\n", server->args.shm_path, + strerror(errno)); + goto err_close_shm; + } + state_table = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_SHARED, + shm_fd, 0); + if (state_table == MAP_FAILED) { + fprintf(stderr, "mmap failed: %s\n", strerror(errno)); + goto err_close_shm; + } + + IVSHMEM_SERVER_DEBUG(server, "create & bind socket %s\n", + server->args.unix_socket_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_unmap; + } + + sun.sun_family = AF_UNIX; + ret = snprintf(sun.sun_path, sizeof(sun.sun_path), "%s", + server->args.unix_socket_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; + server->state_table = state_table; + + return 0; + +err_close_sock: + close(sock_fd); +err_unmap: + munmap(state_table, 4096); +err_close_shm: + if (server->args.use_shm_open) { + shm_unlink(server->args.shm_path); + } + close(shm_fd); + shm_unlink(server->args.shm_path); + 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->args.unix_socket_path); + if (server->args.use_shm_open) { + shm_unlink(server->args.shm_path); + } + close(server->sock_fd); + munmap(server->state_table, 4096); + 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, int64_t peer_id) +{ + IvshmemServerPeer *peer; + + QTAILQ_FOREACH(peer, &server->peer_list, next) { + if (peer->id == peer_id) { + return peer; + } + } + return NULL; +} diff --git a/contrib/ivshmem2-server/ivshmem2-server.h b/contrib/ivshmem2-server/ivshmem2-server.h new file mode 100644 index 0000000000..3fd6166577 --- /dev/null +++ b/contrib/ivshmem2-server/ivshmem2-server.h @@ -0,0 +1,158 @@ +/* + * Copyright 6WIND S.A., 2014 + * Copyright (c) Siemens AG, 2019 + * + * 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 IVSHMEM2_SERVER_H +#define IVSHMEM2_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 being + * "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/ivshmem2.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; + +/** + * Structure describing ivshmem server arguments + */ +typedef struct IvshmemServerArgs { + bool verbose; /**< true to enable verbose mode */ + const char *unix_socket_path; /**< pointer to unix socket file name */ + const char *shm_path; /**< Path to the shared memory; path + corresponds to a POSIX shm name or a + hugetlbfs mount point. */ + bool use_shm_open; /**< true to use shm_open, false for + file-backed shared memory */ + uint64_t shm_size; /**< total size of shared memory */ + uint64_t output_section_size; /**< size of each output section */ + unsigned max_peers; /**< maximum number of peers */ + unsigned vectors; /**< interrupt vectors per client */ + unsigned protocol; /**< protocol advertised to all clients */ +} IvshmemServerArgs; + +/** + * 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 { + IvshmemServerArgs args; /**< server arguments */ + int sock_fd; /**< unix sock file descriptor */ + int shm_fd; /**< shm file descriptor */ + uint32_t *state_table; /**< mapped state table */ + QTAILQ_HEAD(, IvshmemServerPeer) peer_list; /**< list of peers */ +} IvshmemServer; + +/** + * Initialize an ivshmem server + * + * @server: A pointer to an uninitialized IvshmemServer structure + */ +void ivshmem_server_init(IvshmemServer *server); + +/** + * 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); + +#endif /* IVSHMEM2_SERVER_H */ diff --git a/contrib/ivshmem2-server/main.c b/contrib/ivshmem2-server/main.c new file mode 100644 index 0000000000..35cd6fca0f --- /dev/null +++ b/contrib/ivshmem2-server/main.c @@ -0,0 +1,313 @@ +/* + * Copyright 6WIND S.A., 2014 + * Copyright (c) Siemens AG, 2019 + * + * 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/osdep.h" +#include "qapi/error.h" +#include "qemu/cutils.h" +#include "qemu/option.h" +#include "ivshmem2-server.h" + +#define IVSHMEM_SERVER_DEFAULT_FOREGROUND 0 +#define IVSHMEM_SERVER_DEFAULT_PID_FILE "/var/run/ivshmem-server.pid" + +#define IVSHMEM_SERVER_DEFAULT_VERBOSE 0 +#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_OUTPUT_SEC_SZ 0 +#define IVSHMEM_SERVER_DEFAULT_MAX_PEERS 2 +#define IVSHMEM_SERVER_DEFAULT_VECTORS 1 +#define IVSHMEM_SERVER_DEFAULT_PROTOCOL 0 + +/* used to quit on signal SIGTERM */ +static int ivshmem_server_quit; + +static bool foreground = IVSHMEM_SERVER_DEFAULT_FOREGROUND; +static const char *pid_file = IVSHMEM_SERVER_DEFAULT_PID_FILE; + +static void +ivshmem_server_usage(const char *progname) +{ + printf("Usage: %s [OPTION]...\n" + " -h: show this help\n" + " -v: verbose mode\n" + " -F: foreground mode (default is to daemonize)\n" + " -p <pid-file>: path to the PID file (used in daemon mode only)\n" + " default " IVSHMEM_SERVER_DEFAULT_PID_FILE "\n" + " -S <unix-socket-path>: path to the unix socket to listen to\n" + " default " IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH "\n" + " -M <shm-name>: POSIX shared memory object to use\n" + " default " IVSHMEM_SERVER_DEFAULT_SHM_PATH "\n" + " -m <dir-name>: where to create shared memory\n" + " -l <size>: size of shared memory in bytes\n" + " suffixes K, M and G can be used, e.g. 1K means 1024\n" + " default %u\n" + " -o <size>: size of each output section in bytes " + "(suffixes supported)\n" + " default %u\n" + " -n <peers>: maximum number of peers\n" + " default %u\n" + " -V <vectors>: number of vectors\n" + " default %u\n" + " -P <protocol>: 16-bit protocol to be advertised\n" + " default 0x%04x\n" + " When using virtio (0x8000...0xffff), only two peers are " + "supported, peer 0\n" + " will become backend, peer 1 frontend\n", + progname, IVSHMEM_SERVER_DEFAULT_SHM_SIZE, + IVSHMEM_SERVER_DEFAULT_OUTPUT_SEC_SZ, + IVSHMEM_SERVER_DEFAULT_MAX_PEERS, IVSHMEM_SERVER_DEFAULT_VECTORS, + IVSHMEM_SERVER_DEFAULT_PROTOCOL); +} + +static void +ivshmem_server_help(const char *progname) +{ + fprintf(stderr, "Try '%s -h' for more information.\n", progname); +} + +/* 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 *err = NULL; + + while ((c = getopt(argc, argv, "hvFp:S:m:M:l:o:n:V:P:")) != -1) { + + switch (c) { + case 'h': /* help */ + ivshmem_server_usage(argv[0]); + exit(0); + break; + + case 'v': /* verbose */ + args->verbose = 1; + break; + + case 'F': /* foreground */ + foreground = 1; + break; + + case 'p': /* pid file */ + pid_file = optarg; + break; + + case 'S': /* unix socket path */ + args->unix_socket_path = optarg; + break; + + case 'M': /* shm name */ + case 'm': /* dir name */ + args->shm_path = optarg; + args->use_shm_open = c == 'M'; + break; + + case 'l': /* shm size */ + parse_option_size("shm_size", optarg, &args->shm_size, &err); + if (err) { + error_report_err(err); + ivshmem_server_help(argv[0]); + exit(1); + } + break; + + case 'o': /* output section size */ + parse_option_size("output_section_size", optarg, + &args->output_section_size, &err); + if (err) { + error_report_err(err); + ivshmem_server_help(argv[0]); + exit(1); + } + break; + + case 'n': /* maximum number of peers */ + if (parse_uint_full(optarg, &v, 0) < 0) { + fprintf(stderr, "cannot parse max-peers\n"); + ivshmem_server_help(argv[0]); + exit(1); + } + args->max_peers = v; + break; + + case 'V': /* number of vectors */ + if (parse_uint_full(optarg, &v, 0) < 0) { + fprintf(stderr, "cannot parse vectors\n"); + ivshmem_server_help(argv[0]); + exit(1); + } + args->vectors = v; + break; + + case 'P': /* protocol */ + if (parse_uint_full(optarg, &v, 0) < 0) { + fprintf(stderr, "cannot parse protocol\n"); + ivshmem_server_help(argv[0]); + exit(1); + } + args->protocol = v; + break; + + default: + ivshmem_server_usage(argv[0]); + exit(1); + break; + } + } + + if (args->vectors > IVSHMEM_SERVER_MAX_VECTORS) { + fprintf(stderr, "too many requested vectors (max is %d)\n", + IVSHMEM_SERVER_MAX_VECTORS); + ivshmem_server_help(argv[0]); + exit(1); + } + + if (args->protocol >= 0x8000 && args->max_peers > 2) { + fprintf(stderr, "virtio protocols only support 2 peers\n"); + ivshmem_server_help(argv[0]); + exit(1); + } + + if (args->verbose == 1 && foreground == 0) { + fprintf(stderr, "cannot use verbose in daemon mode\n"); + ivshmem_server_help(argv[0]); + exit(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 = { + .args = { + .verbose = IVSHMEM_SERVER_DEFAULT_VERBOSE, + .unix_socket_path = IVSHMEM_SERVER_DEFAULT_UNIX_SOCK_PATH, + .shm_path = IVSHMEM_SERVER_DEFAULT_SHM_PATH, + .use_shm_open = true, + .shm_size = IVSHMEM_SERVER_DEFAULT_SHM_SIZE, + .output_section_size = IVSHMEM_SERVER_DEFAULT_OUTPUT_SEC_SZ, + .max_peers = IVSHMEM_SERVER_DEFAULT_MAX_PEERS, + .vectors = IVSHMEM_SERVER_DEFAULT_VECTORS, + .protocol = IVSHMEM_SERVER_DEFAULT_PROTOCOL, + }, + }; + struct sigaction sa, sa_quit; + int ret = 1; + + /* + * Do not remove this notice without adding proper error handling! + * Start with handling ivshmem_server_send_one_msg() failure. + */ + printf("*** Example code, do not use in production ***\n"); + + /* parse arguments, will exit on error */ + ivshmem_server_parse_args(&server.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 || + sigaction(SIGINT, &sa_quit, 0) == -1) { + perror("failed to add signal handler; sigaction"); + goto err; + } + + /* init the ivshms structure */ + ivshmem_server_init(&server); + + /* 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 (!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(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; +}