From 065e281356282f59386272aa50590b566a1809d9 Mon Sep 17 00:00:00 2001 From: aliguori Date: Tue, 11 Nov 2008 16:46:33 +0000 Subject: [PATCH] Reintroduce migrate-to-exec: support (Charles Duffy) 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 Signed-off-by: Anthony Liguori git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5694 c046a42c-6fe2-441c-8c8c-71466251a162 --- Makefile.target | 2 +- hw/hw.h | 2 + migration-exec.c | 141 +++++++++++++++++++++++++++++++++++ migration-tcp.c | 188 +++++------------------------------------------ migration.c | 178 ++++++++++++++++++++++++++++++++++++++++++++ migration.h | 49 ++++++++++++ vl.c | 64 ++++++++++++++++ 7 files changed, 453 insertions(+), 171 deletions(-) create mode 100644 migration-exec.c diff --git a/Makefile.target b/Makefile.target index 031ab456ec..d844d9c979 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 99d4b8d755..eab7bb4db1 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 0000000000..5d0b215fd1 --- /dev/null +++ b/migration-exec.c @@ -0,0 +1,141 @@ +/* + * 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 + +#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 int file_errno(FdMigrationState *s) +{ + return errno; +} + +static int file_write(FdMigrationState *s, const void * buf, size_t size) +{ + return write(s->fd, buf, size); +} + +static int exec_close(FdMigrationState *s) +{ + dprintf("exec_close\n"); + if (s->opaque) { + qemu_fclose(s->opaque); + s->opaque = NULL; + s->fd = -1; + } + return 0; +} + +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->opaque = qemu_popen(f, "w"); + + s->get_error = file_errno; + s->write = file_write; + 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->detach = !async; + s->bandwidth_limit = bandwidth_limit; + + if (s->detach == 1) { + dprintf("detaching from monitor\n"); + monitor_suspend(); + s->detach = 2; + } + + migrate_fd_connect(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-tcp.c b/migration-tcp.c index f13dc0da7d..100644ba27 100644 --- a/migration-tcp.c +++ b/migration-tcp.c @@ -22,16 +22,6 @@ //#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) @@ -40,64 +30,19 @@ typedef struct FdMigrationState do { } while (0) #endif -static void tcp_cleanup(FdMigrationState *s) +static int socket_errno(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; + return (s->get_error(s)); } -static void tcp_error(FdMigrationState *s) +static int socket_write(FdMigrationState *s, const void * buf, size_t size) { - dprintf("setting error state\n"); - s->state = MIG_STATE_ERROR; - tcp_cleanup(s); + return send(s->fd, buf, size, 0); } -static void fd_put_notify(void *opaque) +static int tcp_close(FdMigrationState *s) { - 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 = send(s->fd, data, size, 0); - } while (ret == -1 && (socket_error() == EINTR || socket_error() == EWOULDBLOCK)); - - if (ret == -1) - ret = -socket_error(); - - 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"); + dprintf("tcp_close\n"); if (s->fd != -1) { close(s->fd); s->fd = -1; @@ -105,67 +50,6 @@ static int fd_close(void *opaque) 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 && socket_error() == 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) { @@ -176,62 +60,23 @@ static void tcp_wait_for_connect(void *opaque) dprintf("connect completed\n"); do { ret = getsockopt(s->fd, SOL_SOCKET, SO_ERROR, &val, &valsize); - } while (ret == -1 && socket_error() == EINTR); + } while (ret == -1 && (s->get_error(s)) == EINTR); if (ret < 0) { - tcp_error(s); + migrate_fd_error(s); return; } qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); if (val == 0) - tcp_connect_migrate(s); + migrate_fd_connect(s); else { dprintf("error connecting %d\n", val); - tcp_error(s); + migrate_fd_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) @@ -247,9 +92,12 @@ MigrationState *tcp_start_outgoing_migration(const char *host_port, 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->get_error = socket_errno; + s->write = socket_write; + s->close = tcp_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->detach = !async; @@ -271,7 +119,7 @@ MigrationState *tcp_start_outgoing_migration(const char *host_port, do { ret = connect(s->fd, (struct sockaddr *)&addr, sizeof(addr)); if (ret == -1) - ret = -socket_error(); + ret = -(s->get_error(s)); if (ret == -EINPROGRESS || ret == -EWOULDBLOCK) qemu_set_fd_handler2(s->fd, NULL, NULL, tcp_wait_for_connect, s); @@ -283,7 +131,7 @@ MigrationState *tcp_start_outgoing_migration(const char *host_port, qemu_free(s); return NULL; } else if (ret >= 0) - tcp_connect_migrate(s); + migrate_fd_connect(s); return &s->mig_state; } diff --git a/migration.c b/migration.c index 9e6c43731e..0ef777adde 100644 --- a/migration.c +++ b/migration.c @@ -14,6 +14,20 @@ #include "qemu-common.h" #include "migration.h" #include "console.h" +#include "buffered_file.h" +#include "sysemu.h" +#include "block.h" +#include "qemu_socket.h" + +//#define DEBUG_MIGRATION + +#ifdef DEBUG_MIGRATION +#define dprintf(fmt, ...) \ + do { printf("migration: " fmt, ## __VA_ARGS__); } while (0) +#else +#define dprintf(fmt, ...) \ + do { } while (0) +#endif /* Migration speed throttling */ static uint32_t max_throttle = (32 << 20); @@ -26,6 +40,10 @@ 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 +55,10 @@ 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); @@ -101,3 +123,159 @@ void do_info_migrate(void) } } +/* shared migration helpers */ + +void migrate_fd_error(FdMigrationState *s) +{ + dprintf("setting error state\n"); + s->state = MIG_STATE_ERROR; + migrate_fd_cleanup(s); +} + +void migrate_fd_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; +} + +void migrate_fd_put_notify(void *opaque) +{ + FdMigrationState *s = opaque; + + qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL); + qemu_file_put_notify(s->file); +} + +ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size) +{ + FdMigrationState *s = opaque; + ssize_t ret; + + do { + ret = s->write(s, data, size); + } while (ret == -1 && ((s->get_error(s)) == EINTR || (s->get_error(s)) == EWOULDBLOCK)); + + if (ret == -1) + ret = -(s->get_error(s)); + + if (ret == -EAGAIN) + qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s); + + return ret; +} + +void migrate_fd_connect(FdMigrationState *s) +{ + int ret; + + s->file = qemu_fopen_ops_buffered(s, + s->bandwidth_limit, + migrate_fd_put_buffer, + migrate_fd_put_ready, + migrate_fd_wait_for_unfreeze, + migrate_fd_close); + + dprintf("beginning savevm\n"); + ret = qemu_savevm_state_begin(s->file); + if (ret < 0) { + dprintf("failed, %d\n", ret); + migrate_fd_error(s); + return; + } + + migrate_fd_put_ready(s); +} + +void migrate_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; + migrate_fd_cleanup(s); + } +} + +int migrate_fd_get_status(MigrationState *mig_state) +{ + FdMigrationState *s = migrate_to_fms(mig_state); + return s->state; +} + +void migrate_fd_cancel(MigrationState *mig_state) +{ + FdMigrationState *s = migrate_to_fms(mig_state); + + if (s->state != MIG_STATE_ACTIVE) + return; + + dprintf("cancelling migration\n"); + + s->state = MIG_STATE_CANCELLED; + + migrate_fd_cleanup(s); +} + +void migrate_fd_release(MigrationState *mig_state) +{ + FdMigrationState *s = migrate_to_fms(mig_state); + + dprintf("releasing state\n"); + + if (s->state == MIG_STATE_ACTIVE) { + s->state = MIG_STATE_CANCELLED; + migrate_fd_cleanup(s); + } + free(s); +} + +void migrate_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 && (s->get_error(s)) == EINTR); +} + +int migrate_fd_close(void *opaque) +{ + FdMigrationState *s = opaque; + return s->close(s); +} diff --git a/migration.h b/migration.h index 9947f6a45f..953ec704de 100644 --- a/migration.h +++ b/migration.h @@ -29,6 +29,22 @@ struct MigrationState void (*release)(MigrationState *s); }; +typedef struct FdMigrationState FdMigrationState; + +struct FdMigrationState +{ + MigrationState mig_state; + int64_t bandwidth_limit; + QEMUFile *file; + int fd; + int detach; + int state; + int (*get_error)(struct FdMigrationState*); + int (*close)(struct FdMigrationState*); + int (*write)(struct FdMigrationState*, const void *, size_t); + void *opaque; +}; + void qemu_start_incoming_migration(const char *uri); void do_migrate(int detach, const char *uri); @@ -39,11 +55,44 @@ 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, int64_t bandwidth_limit, int detach); +void migrate_fd_error(FdMigrationState *s); + +void migrate_fd_cleanup(FdMigrationState *s); + +void migrate_fd_put_notify(void *opaque); + +ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size); + +void migrate_fd_connect(FdMigrationState *s); + +void migrate_fd_put_ready(void *opaque); + +int migrate_fd_get_status(MigrationState *mig_state); + +void migrate_fd_cancel(MigrationState *mig_state); + +void migrate_fd_release(MigrationState *mig_state); + +void migrate_fd_wait_for_unfreeze(void *opaque); + +int migrate_fd_close(void *opaque); + +static inline FdMigrationState *migrate_to_fms(MigrationState *mig_state) +{ + return container_of(mig_state, FdMigrationState, mig_state); +} + #endif diff --git a/vl.c b/vl.c index 7bcffd334a..daad89ffd8 100644 --- a/vl.c +++ b/vl.c @@ -2964,6 +2964,12 @@ struct QEMUFile { int has_error; }; +typedef struct QEMUFilePopen +{ + FILE *popen_file; + QEMUFile *file; +} QEMUFilePopen; + typedef struct QEMUFileSocket { int fd; @@ -2992,6 +2998,64 @@ 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));