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-rw-r--r--migration-unix.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/migration-unix.c b/migration-unix.c
new file mode 100644
index 0000000000..a26587a3ea
--- /dev/null
+++ b/migration-unix.c
@@ -0,0 +1,216 @@
+/*
+ * QEMU live migration via Unix Domain Sockets
+ *
+ * Copyright Red Hat, Inc. 2009
+ *
+ * Authors:
+ * Chris Lalancette <clalance@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu-common.h"
+#include "qemu_socket.h"
+#include "migration.h"
+#include "qemu-char.h"
+#include "sysemu.h"
+#include "buffered_file.h"
+#include "block.h"
+
+//#define DEBUG_MIGRATION_UNIX
+
+#ifdef DEBUG_MIGRATION_UNIX
+#define dprintf(fmt, ...) \
+ do { printf("migration-unix: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define dprintf(fmt, ...) \
+ do { } while (0)
+#endif
+
+static int unix_errno(FdMigrationState *s)
+{
+ return errno;
+}
+
+static int unix_write(FdMigrationState *s, const void * buf, size_t size)
+{
+ return write(s->fd, buf, size);
+}
+
+static int unix_close(FdMigrationState *s)
+{
+ dprintf("unix_close\n");
+ if (s->fd != -1) {
+ close(s->fd);
+ s->fd = -1;
+ }
+ return 0;
+}
+
+static void unix_wait_for_connect(void *opaque)
+{
+ FdMigrationState *s = opaque;
+ int val, ret;
+ socklen_t valsize = sizeof(val);
+
+ dprintf("connect completed\n");
+ do {
+ ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, (void *) &val, &valsize);
+ } while (ret == -1 && (s->get_error(s)) == EINTR);
+
+ if (ret < 0) {
+ migrate_fd_error(s);
+ return;
+ }
+
+ qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
+
+ if (val == 0)
+ migrate_fd_connect(s);
+ else {
+ dprintf("error connecting %d\n", val);
+ migrate_fd_error(s);
+ }
+}
+
+MigrationState *unix_start_outgoing_migration(const char *path,
+ int64_t bandwidth_limit,
+ int detach)
+{
+ FdMigrationState *s;
+ struct sockaddr_un addr;
+ int ret;
+
+ addr.sun_family = AF_UNIX;
+ snprintf(addr.sun_path, sizeof(addr.sun_path), "%s", path);
+
+ s = qemu_mallocz(sizeof(*s));
+
+ s->get_error = unix_errno;
+ s->write = unix_write;
+ s->close = unix_close;
+ s->mig_state.cancel = migrate_fd_cancel;
+ s->mig_state.get_status = migrate_fd_get_status;
+ s->mig_state.release = migrate_fd_release;
+
+ s->state = MIG_STATE_ACTIVE;
+ s->mon_resume = NULL;
+ s->bandwidth_limit = bandwidth_limit;
+ s->fd = socket(PF_UNIX, SOCK_STREAM, 0);
+ if (s->fd < 0) {
+ dprintf("Unable to open socket");
+ goto err_after_alloc;
+ }
+
+ socket_set_nonblock(s->fd);
+
+ if (!detach)
+ migrate_fd_monitor_suspend(s);
+
+ do {
+ ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
+ if (ret == -1)
+ ret = -(s->get_error(s));
+
+ if (ret == -EINPROGRESS || ret == -EWOULDBLOCK)
+ qemu_set_fd_handler2(s->fd, NULL, NULL, unix_wait_for_connect, s);
+ } while (ret == -EINTR);
+
+ if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) {
+ dprintf("connect failed\n");
+ goto err_after_open;
+ } else if (ret >= 0)
+ migrate_fd_connect(s);
+
+ return &s->mig_state;
+
+err_after_open:
+ close(s->fd);
+
+err_after_alloc:
+ qemu_free(s);
+ return NULL;
+}
+
+static void unix_accept_incoming_migration(void *opaque)
+{
+ struct sockaddr_un addr;
+ socklen_t addrlen = sizeof(addr);
+ int s = (unsigned long)opaque;
+ QEMUFile *f;
+ int c, ret;
+
+ do {
+ c = accept(s, (struct sockaddr *)&addr, &addrlen);
+ } while (c == -1 && socket_error() == EINTR);
+
+ dprintf("accepted migration\n");
+
+ if (c == -1) {
+ fprintf(stderr, "could not accept migration connection\n");
+ return;
+ }
+
+ f = qemu_fopen_socket(c);
+ if (f == NULL) {
+ fprintf(stderr, "could not qemu_fopen socket\n");
+ goto out;
+ }
+
+ ret = qemu_loadvm_state(f);
+ if (ret < 0) {
+ fprintf(stderr, "load of migration failed\n");
+ goto out_fopen;
+ }
+ qemu_announce_self();
+ dprintf("successfully loaded vm state\n");
+
+ /* we've successfully migrated, close the server socket */
+ qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
+ close(s);
+
+out_fopen:
+ qemu_fclose(f);
+out:
+ close(c);
+}
+
+int unix_start_incoming_migration(const char *path)
+{
+ struct sockaddr_un un;
+ int sock;
+
+ dprintf("Attempting to start an incoming migration\n");
+
+ sock = socket(PF_UNIX, SOCK_STREAM, 0);
+ if (sock < 0) {
+ fprintf(stderr, "Could not open unix socket: %s\n", strerror(errno));
+ return -EINVAL;
+ }
+
+ memset(&un, 0, sizeof(un));
+ un.sun_family = AF_UNIX;
+ snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
+
+ unlink(un.sun_path);
+ if (bind(sock, (struct sockaddr*) &un, sizeof(un)) < 0) {
+ fprintf(stderr, "bind(unix:%s): %s\n", un.sun_path, strerror(errno));
+ goto err;
+ }
+ if (listen(sock, 1) < 0) {
+ fprintf(stderr, "listen(unix:%s): %s\n", un.sun_path, strerror(errno));
+ goto err;
+ }
+
+ qemu_set_fd_handler2(sock, NULL, unix_accept_incoming_migration, NULL,
+ (void *)(unsigned long)sock);
+
+ return 0;
+
+err:
+ close(sock);
+
+ return -EINVAL;
+}