diff --git a/Makefile.target b/Makefile.target index 031ab45..d844d9c 100644 --- a/Makefile.target +++ b/Makefile.target @@ -596,7 +596,7 @@ endif ifdef CONFIG_WIN32 OBJS+=block-raw-win32.o else -OBJS+=block-raw-posix.o +OBJS+=block-raw-posix.o migration-exec.o endif LIBS+=-lz diff --git a/hw/hw.h b/hw/hw.h index 99d4b8d..eab7bb4 100644 --- a/hw/hw.h +++ b/hw/hw.h @@ -35,6 +35,8 @@ QEMUFile *qemu_fopen_ops(void *opaque, QEMUFilePutBufferFunc *put_buffer, QEMUFileRateLimit *rate_limit); QEMUFile *qemu_fopen(const char *filename, const char *mode); QEMUFile *qemu_fopen_socket(int fd); +QEMUFile *qemu_popen(FILE *popen_file, const char *mode); +QEMUFile *qemu_popen_cmd(const char *command, const char *mode); void qemu_fflush(QEMUFile *f); int qemu_fclose(QEMUFile *f); void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size); diff --git a/migration-exec.c b/migration-exec.c new file mode 100644 index 0000000..2d04008 --- /dev/null +++ b/migration-exec.c @@ -0,0 +1,295 @@ +/* + * QEMU live migration + * + * Copyright IBM, Corp. 2008 + * Copyright Dell MessageOne 2008 + * + * Authors: + * Anthony Liguori + * Charles Duffy + * + * 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_EXEC + +typedef struct FdMigrationState +{ + MigrationState mig_state; + QEMUFile *file, *popen_file; + int64_t bandwidth_limit; + int fd; + int detach; + int state; +} FdMigrationState; + +#ifdef DEBUG_MIGRATION_EXEC +#define dprintf(fmt, ...) \ + do { printf("migration-exec: " fmt, ## __VA_ARGS__); } while (0) +#else +#define dprintf(fmt, ...) \ + do { } while (0) +#endif + +static void exec_cleanup(FdMigrationState *s) +{ + qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); + + if (s->file) { + dprintf("closing file\n"); + qemu_fclose(s->file); + } + + if (s->fd != -1) + close(s->fd); + + /* Don't resume monitor until we've flushed all of the buffers */ + if (s->detach == 2) { + monitor_resume(); + s->detach = 0; + } + + s->fd = -1; +} + +static void exec_error(FdMigrationState *s) +{ + dprintf("setting error state\n"); + s->state = MIG_STATE_ERROR; + exec_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 || errno == EWOULDBLOCK)); + + 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->popen_file) { + qemu_fclose(s->popen_file); + s->popen_file = NULL; + 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; + exec_cleanup(s); + } +} + +static void exec_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); + exec_error(s); + return; + } + + fd_put_ready(s); +} + +static FdMigrationState *to_fms(MigrationState *mig_state) +{ + return container_of(mig_state, FdMigrationState, mig_state); +} + +static int exec_get_status(MigrationState *mig_state) +{ + FdMigrationState *s = to_fms(mig_state); + + return s->state; +} + +static void exec_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; + + exec_cleanup(s); +} + +static void exec_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; + exec_cleanup(s); + } + free(s); +} + +MigrationState *exec_start_outgoing_migration(const char *command, + int64_t bandwidth_limit, + int async) +{ + FdMigrationState *s; + FILE *f; + + s = qemu_mallocz(sizeof(*s)); + if (s == NULL) { + dprintf("Unable to allocate FdMigrationState\n"); + goto err; + } + + f = popen(command, "w"); + if (f == NULL) { + dprintf("Unable to popen exec target\n"); + goto err_after_alloc; + } + + s->fd = fileno(f); + if (s->fd == -1) { + dprintf("Unable to retrieve file descriptor for popen'd handle\n"); + goto err_after_open; + } + + if (fcntl(s->fd, F_SETFD, O_NONBLOCK) == -1) { + dprintf("Unable to set nonblocking mode on file descriptor\n"); + goto err_after_open; + } + + s->popen_file = qemu_popen(f, "w"); + + s->mig_state.cancel = exec_cancel; + s->mig_state.get_status = exec_get_status; + s->mig_state.release = exec_release; + + s->state = MIG_STATE_ACTIVE; + s->detach = !async; + s->bandwidth_limit = bandwidth_limit; + + if (s->detach == 1) { + dprintf("detaching from monitor\n"); + monitor_suspend(); + s->detach = 2; + } + + exec_connect_migrate(s); + return &s->mig_state; + +err_after_open: + pclose(f); +err_after_alloc: + qemu_free(s); +err: + return NULL; +} + +int exec_start_incoming_migration(const char *command) +{ + int ret; + QEMUFile *f; + + dprintf("Attempting to start an incoming migration\n"); + f = qemu_popen_cmd(command, "r"); + if(f == NULL) { + dprintf("Unable to apply qemu wrapper to popen file\n"); + return -errno; + } + vm_stop(0); /* just in case */ + ret = qemu_loadvm_state(f); + if (ret < 0) { + fprintf(stderr, "load of migration failed\n"); + goto err; + } + qemu_announce_self(); + dprintf("successfully loaded vm state\n"); + vm_start(); + qemu_fclose(f); + return 0; + +err: + qemu_fclose(f); + return -errno; +} diff --git a/migration.c b/migration.c index 9e6c437..fb4d3d3 100644 --- a/migration.c +++ b/migration.c @@ -26,6 +26,10 @@ void qemu_start_incoming_migration(const char *uri) if (strstart(uri, "tcp:", &p)) tcp_start_incoming_migration(p); +#if !defined(WIN32) + else if (strstart(uri, "exec:", &p)) + exec_start_incoming_migration(p); +#endif else fprintf(stderr, "unknown migration protocol: %s\n", uri); } @@ -37,6 +41,10 @@ void do_migrate(int detach, const char *uri) if (strstart(uri, "tcp:", &p)) s = tcp_start_outgoing_migration(p, max_throttle, detach); +#if !defined(WIN32) + else if (strstart(uri, "exec:", &p)) + s = exec_start_outgoing_migration(p, max_throttle, detach); +#endif else term_printf("unknown migration protocol: %s\n", uri); diff --git a/migration.h b/migration.h index 9947f6a..5008323 100644 --- a/migration.h +++ b/migration.h @@ -39,6 +39,12 @@ void do_migrate_set_speed(const char *value); void do_info_migrate(void); +int exec_start_incoming_migration(const char *host_port); + +MigrationState *exec_start_outgoing_migration(const char *host_port, + int64_t bandwidth_limit, + int detach); + int tcp_start_incoming_migration(const char *host_port); MigrationState *tcp_start_outgoing_migration(const char *host_port, diff --git a/vl.c b/vl.c index 31dd3d7..b49e694 100644 --- a/vl.c +++ b/vl.c @@ -2816,6 +2816,12 @@ struct QEMUFile { int has_error; }; +typedef struct QEMUFilePopen +{ + FILE *popen_file; + QEMUFile *file; +} QEMUFilePopen; + typedef struct QEMUFileSocket { int fd; @@ -2844,6 +2850,64 @@ static int socket_close(void *opaque) return 0; } +static int popen_put_buffer(void *opaque, const uint8_t *buf, int64_t pos, int size) +{ + QEMUFilePopen *s = opaque; + return fwrite(buf, 1, size, s->popen_file); +} + +static int popen_get_buffer(void *opaque, uint8_t *buf, int64_t pos, int size) +{ + QEMUFilePopen *s = opaque; + return fread(buf, 1, size, s->popen_file); +} + +static int popen_close(void *opaque) +{ + QEMUFilePopen *s = opaque; + pclose(s->popen_file); + qemu_free(s); + return 0; +} + +QEMUFile *qemu_popen(FILE *popen_file, const char *mode) +{ + QEMUFilePopen *s; + + if (popen_file == NULL || mode == NULL || (mode[0] != 'r' && mode[0] != 'w') || mode[1] != 0) { + fprintf(stderr, "qemu_popen: Argument validity check failed\n"); + return NULL; + } + + s = qemu_mallocz(sizeof(QEMUFilePopen)); + if (!s) { + fprintf(stderr, "qemu_popen: malloc failed\n"); + return NULL; + } + + s->popen_file = popen_file; + + if(mode[0] == 'r') { + s->file = qemu_fopen_ops(s, NULL, popen_get_buffer, popen_close, NULL); + } else { + s->file = qemu_fopen_ops(s, popen_put_buffer, NULL, popen_close, NULL); + } + fprintf(stderr, "qemu_popen: returning result of qemu_fopen_ops\n"); + return s->file; +} + +QEMUFile *qemu_popen_cmd(const char *command, const char *mode) +{ + FILE *popen_file; + + popen_file = popen(command, mode); + if(popen_file == NULL) { + return NULL; + } + + return qemu_popen(popen_file, mode); +} + QEMUFile *qemu_fopen_socket(int fd) { QEMUFileSocket *s = qemu_mallocz(sizeof(QEMUFileSocket));