KVM's live migration support included support for exec: URLs, allowing system state to be written or received via an arbitrary popen()ed subprocess. This provides a convenient way to pipe state through a compression algorithm or an arbitrary network transport on its way to its destination, and a convenient way to write state to disk; libvirt's qemu driver currently uses migration to exec: targets for this latter purpose. This version of the patch refactors now-common code from migrate-tcp.c into migrate.c. Signed-off-by: Charles Duffy <Charles_Duffy@messageone.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5694 c046a42c-6fe2-441c-8c8c-71466251a162
218 lines
4.9 KiB
C
218 lines
4.9 KiB
C
/*
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* QEMU live migration
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*
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* Copyright IBM, Corp. 2008
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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*/
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#include "qemu-common.h"
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#include "qemu_socket.h"
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#include "migration.h"
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#include "qemu-char.h"
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#include "sysemu.h"
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#include "console.h"
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#include "buffered_file.h"
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#include "block.h"
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//#define DEBUG_MIGRATION_TCP
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#ifdef DEBUG_MIGRATION_TCP
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#define dprintf(fmt, ...) \
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do { printf("migration-tcp: " fmt, ## __VA_ARGS__); } while (0)
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#else
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#define dprintf(fmt, ...) \
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do { } while (0)
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#endif
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static int socket_errno(FdMigrationState *s)
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{
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return (s->get_error(s));
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}
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static int socket_write(FdMigrationState *s, const void * buf, size_t size)
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{
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return send(s->fd, buf, size, 0);
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}
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static int tcp_close(FdMigrationState *s)
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{
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dprintf("tcp_close\n");
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if (s->fd != -1) {
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close(s->fd);
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s->fd = -1;
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}
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return 0;
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}
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static void tcp_wait_for_connect(void *opaque)
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{
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FdMigrationState *s = opaque;
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int val, ret;
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socklen_t valsize = sizeof(val);
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dprintf("connect completed\n");
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do {
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ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, &val, &valsize);
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} while (ret == -1 && (s->get_error(s)) == EINTR);
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if (ret < 0) {
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migrate_fd_error(s);
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return;
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}
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qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
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if (val == 0)
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migrate_fd_connect(s);
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else {
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dprintf("error connecting %d\n", val);
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migrate_fd_error(s);
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}
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}
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MigrationState *tcp_start_outgoing_migration(const char *host_port,
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int64_t bandwidth_limit,
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int async)
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{
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struct sockaddr_in addr;
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FdMigrationState *s;
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int ret;
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if (parse_host_port(&addr, host_port) < 0)
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return NULL;
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s = qemu_mallocz(sizeof(*s));
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if (s == NULL)
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return NULL;
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s->get_error = socket_errno;
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s->write = socket_write;
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s->close = tcp_close;
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s->mig_state.cancel = migrate_fd_cancel;
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s->mig_state.get_status = migrate_fd_get_status;
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s->mig_state.release = migrate_fd_release;
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s->state = MIG_STATE_ACTIVE;
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s->detach = !async;
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s->bandwidth_limit = bandwidth_limit;
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s->fd = socket(PF_INET, SOCK_STREAM, 0);
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if (s->fd == -1) {
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qemu_free(s);
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return NULL;
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}
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socket_set_nonblock(s->fd);
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if (s->detach == 1) {
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dprintf("detaching from monitor\n");
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monitor_suspend();
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s->detach = 2;
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}
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do {
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ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr));
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if (ret == -1)
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ret = -(s->get_error(s));
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if (ret == -EINPROGRESS || ret == -EWOULDBLOCK)
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qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s);
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} while (ret == -EINTR);
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if (ret < 0 && ret != -EINPROGRESS && ret != -EWOULDBLOCK) {
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dprintf("connect failed\n");
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close(s->fd);
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qemu_free(s);
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return NULL;
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} else if (ret >= 0)
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migrate_fd_connect(s);
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return &s->mig_state;
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}
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static void tcp_accept_incoming_migration(void *opaque)
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{
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struct sockaddr_in addr;
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socklen_t addrlen = sizeof(addr);
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int s = (unsigned long)opaque;
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QEMUFile *f;
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int c, ret;
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do {
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c = accept(s, (struct sockaddr *)&addr, &addrlen);
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} while (c == -1 && socket_error() == EINTR);
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dprintf("accepted migration\n");
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if (c == -1) {
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fprintf(stderr, "could not accept migration connection\n");
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return;
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}
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f = qemu_fopen_socket(c);
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if (f == NULL) {
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fprintf(stderr, "could not qemu_fopen socket\n");
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goto out;
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}
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vm_stop(0); /* just in case */
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ret = qemu_loadvm_state(f);
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if (ret < 0) {
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fprintf(stderr, "load of migration failed\n");
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goto out_fopen;
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}
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qemu_announce_self();
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dprintf("successfully loaded vm state\n");
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/* we've successfully migrated, close the server socket */
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qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
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close(s);
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vm_start();
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out_fopen:
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qemu_fclose(f);
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out:
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close(c);
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}
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int tcp_start_incoming_migration(const char *host_port)
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{
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struct sockaddr_in addr;
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int val;
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int s;
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if (parse_host_port(&addr, host_port) < 0) {
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fprintf(stderr, "invalid host/port combination: %s\n", host_port);
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return -EINVAL;
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}
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s = socket(PF_INET, SOCK_STREAM, 0);
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if (s == -1)
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return -socket_error();
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val = 1;
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setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (const char *)&val, sizeof(val));
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if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
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goto err;
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if (listen(s, 1) == -1)
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goto err;
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qemu_set_fd_handler2(s, NULL, tcp_accept_incoming_migration, NULL,
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(void *)(unsigned long)s);
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return 0;
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err:
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close(s);
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return -socket_error();
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}
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