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authoraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2008-10-13 03:14:31 +0000
committeraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2008-10-13 03:14:31 +0000
commit34c9dd8eea38e94d97e22ac12c2f2aaa0dca59d8 (patch)
tree059b44291d3bc9196d68c8ecdf8a7b940ef99ff2 /migration-tcp.c
parent210f41ba932efb4c32139568930b72d1c2d075be (diff)
Introduce TCP live migration protocol
This patch introduces a tcp protocol for live migration. It can be used as follows: qemu-system-x86_64 -hda ~/images/linux-test.img -monitor stdio <vm runs for a while> (qemu) migrate tcp:localhost:1025 On the same system: qemu-system-x86_64 -hda ~/images/linux-test.img -incoming tcp:localhost:1025 The monitor can be interacted with while waiting for an incoming live migration. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5478 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'migration-tcp.c')
-rw-r--r--migration-tcp.c371
1 files changed, 371 insertions, 0 deletions
diff --git a/migration-tcp.c b/migration-tcp.c
new file mode 100644
index 0000000000..df8080fe7d
--- /dev/null
+++ b/migration-tcp.c
@@ -0,0 +1,371 @@
+/*
+ * QEMU live migration
+ *
+ * Copyright IBM, Corp. 2008
+ *
+ * Authors:
+ * Anthony Liguori <aliguori@us.ibm.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 "console.h"
+#include "buffered_file.h"
+#include "block.h"
+
+//#define DEBUG_MIGRATION_TCP
+
+typedef struct FdMigrationState
+{
+ MigrationState mig_state;
+ QEMUFile *file;
+ int64_t bandwidth_limit;
+ int fd;
+ int detach;
+ int state;
+} FdMigrationState;
+
+#ifdef DEBUG_MIGRATION_TCP
+#define dprintf(fmt, ...) \
+ do { printf("migration-tcp: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define dprintf(fmt, ...) \
+ do { } while (0)
+#endif
+
+int debug_me = 0;
+
+static void tcp_cleanup(FdMigrationState *s)
+{
+ if (s->detach == 2) {
+ monitor_resume();
+ s->detach = 0;
+ }
+
+ qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
+
+ if (s->file) {
+ debug_me = 1;
+ dprintf("closing file\n");
+ qemu_fclose(s->file);
+ }
+
+ if (s->fd != -1)
+ close(s->fd);
+
+ s->fd = -1;
+}
+
+static void tcp_error(FdMigrationState *s)
+{
+ dprintf("setting error state\n");
+ s->state = MIG_STATE_ERROR;
+ tcp_cleanup(s);
+}
+
+static void fd_put_notify(void *opaque)
+{
+ FdMigrationState *s = opaque;
+
+ qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
+ qemu_file_put_notify(s->file);
+}
+
+static ssize_t fd_put_buffer(void *opaque, const void *data, size_t size)
+{
+ FdMigrationState *s = opaque;
+ ssize_t ret;
+
+ do {
+ ret = write(s->fd, data, size);
+ } while (ret == -1 && errno == EINTR);
+
+ if (ret == -1)
+ ret = -errno;
+
+ if (ret == -EAGAIN)
+ qemu_set_fd_handler2(s->fd, NULL, NULL, fd_put_notify, s);
+
+ return ret;
+}
+
+static int fd_close(void *opaque)
+{
+ FdMigrationState *s = opaque;
+ dprintf("fd_close\n");
+ if (s->fd != -1) {
+ close(s->fd);
+ s->fd = -1;
+ }
+ return 0;
+}
+
+static void fd_wait_for_unfreeze(void *opaque)
+{
+ FdMigrationState *s = opaque;
+ int ret;
+
+ dprintf("wait for unfreeze\n");
+ if (s->state != MIG_STATE_ACTIVE)
+ return;
+
+ do {
+ fd_set wfds;
+
+ FD_ZERO(&wfds);
+ FD_SET(s->fd, &wfds);
+
+ ret = select(s->fd + 1, NULL, &wfds, NULL, NULL);
+ } while (ret == -1 && errno == EINTR);
+}
+
+static void fd_put_ready(void *opaque)
+{
+ FdMigrationState *s = opaque;
+
+ if (s->state != MIG_STATE_ACTIVE) {
+ dprintf("put_ready returning because of non-active state\n");
+ return;
+ }
+
+ dprintf("iterate\n");
+ if (qemu_savevm_state_iterate(s->file) == 1) {
+ dprintf("done iterating\n");
+ vm_stop(0);
+
+ bdrv_flush_all();
+ qemu_savevm_state_complete(s->file);
+ s->state = MIG_STATE_COMPLETED;
+ tcp_cleanup(s);
+ }
+}
+
+static void tcp_connect_migrate(FdMigrationState *s)
+{
+ int ret;
+
+ s->file = qemu_fopen_ops_buffered(s,
+ s->bandwidth_limit,
+ fd_put_buffer,
+ fd_put_ready,
+ fd_wait_for_unfreeze,
+ fd_close);
+
+ dprintf("beginning savevm\n");
+ ret = qemu_savevm_state_begin(s->file);
+ if (ret < 0) {
+ dprintf("failed, %d\n", ret);
+ tcp_error(s);
+ return;
+ }
+
+ fd_put_ready(s);
+}
+
+static void tcp_wait_for_connect(void *opaque)
+{
+ FdMigrationState *s = opaque;
+ int val, ret;
+ int valsize = sizeof(val);
+
+ dprintf("connect completed\n");
+ do {
+ ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, &val, &valsize);
+ } while (ret == -1 && errno == EINTR);
+
+ if (ret < 0) {
+ tcp_error(s);
+ return;
+ }
+
+ qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
+
+ if (val == 0)
+ tcp_connect_migrate(s);
+ else {
+ dprintf("error connecting %d\n", val);
+ tcp_error(s);
+ }
+}
+
+static FdMigrationState *to_fms(MigrationState *mig_state)
+{
+ return container_of(mig_state, FdMigrationState, mig_state);
+}
+
+static int tcp_get_status(MigrationState *mig_state)
+{
+ FdMigrationState *s = to_fms(mig_state);
+
+ return s->state;
+}
+
+static void tcp_cancel(MigrationState *mig_state)
+{
+ FdMigrationState *s = to_fms(mig_state);
+
+ if (s->state != MIG_STATE_ACTIVE)
+ return;
+
+ dprintf("cancelling migration\n");
+
+ s->state = MIG_STATE_CANCELLED;
+
+ tcp_cleanup(s);
+}
+
+static void tcp_release(MigrationState *mig_state)
+{
+ FdMigrationState *s = to_fms(mig_state);
+
+ dprintf("releasing state\n");
+
+ if (s->state == MIG_STATE_ACTIVE) {
+ s->state = MIG_STATE_CANCELLED;
+ tcp_cleanup(s);
+ }
+ free(s);
+}
+
+MigrationState *tcp_start_outgoing_migration(const char *host_port,
+ int64_t bandwidth_limit,
+ int async)
+{
+ struct sockaddr_in addr;
+ FdMigrationState *s;
+ int ret;
+
+ if (parse_host_port(&addr, host_port) < 0)
+ return NULL;
+
+ s = qemu_mallocz(sizeof(*s));
+ if (s == NULL)
+ return NULL;
+
+ s->mig_state.cancel = tcp_cancel;
+ s->mig_state.get_status = tcp_get_status;
+ s->mig_state.release = tcp_release;
+
+ s->state = MIG_STATE_ACTIVE;
+ s->detach = !async;
+ s->bandwidth_limit = bandwidth_limit;
+ s->fd = socket(PF_INET, SOCK_STREAM, 0);
+ if (s->fd == -1) {
+ qemu_free(s);
+ return NULL;
+ }
+
+ fcntl(s->fd, F_SETFL, O_NONBLOCK);
+
+ if (s->detach == 1) {
+ dprintf("detaching from monitor\n");
+ monitor_suspend();
+ s->detach = 2;
+ }
+
+ do {
+ ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
+ if (ret == -1)
+ ret = -errno;
+
+ if (ret == -EINPROGRESS)
+ qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
+ } while (ret == -EINTR);
+
+ if (ret < 0 && ret != -EINPROGRESS) {
+ dprintf("connect failed\n");
+ close(s->fd);
+ qemu_free(s);
+ s = NULL;
+ } else if (ret >= 0)
+ tcp_connect_migrate(s);
+
+ return &s->mig_state;
+}
+
+static void tcp_accept_incoming_migration(void *opaque)
+{
+ struct sockaddr_in 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 && errno == EINTR);
+
+ dprintf("accepted migration\n");
+
+ if (c == -1) {
+ fprintf(stderr, "could not accept migration connection\n");
+ return;
+ }
+
+ f = qemu_fopen_fd(c);
+ if (f == NULL) {
+ fprintf(stderr, "could not qemu_fopen socket\n");
+ goto out;
+ }
+
+ vm_stop(0); /* just in case */
+ 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);
+
+ vm_start();
+
+out_fopen:
+ qemu_fclose(f);
+out:
+ close(c);
+}
+
+int tcp_start_incoming_migration(const char *host_port)
+{
+ struct sockaddr_in addr;
+ int val;
+ int s;
+
+ if (parse_host_port(&addr, host_port) < 0) {
+ fprintf(stderr, "invalid host/port combination: %s\n", host_port);
+ return -EINVAL;
+ }
+
+ s = socket(PF_INET, SOCK_STREAM, 0);
+ if (s == -1)
+ return -errno;
+
+ val = 1;
+ setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
+
+ if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
+ goto err;
+
+ if (listen(s, 1) == -1)
+ goto err;
+
+ qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
+ (void *)(unsigned long)s);
+
+ return 0;
+
+err:
+ close(s);
+ return -errno;
+}