065e281356
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
142 lines
3.1 KiB
C
142 lines
3.1 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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* Copyright Dell MessageOne 2008
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*
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* Authors:
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* Anthony Liguori <aliguori@us.ibm.com>
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* Charles Duffy <charles_duffy@messageone.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_EXEC
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#ifdef DEBUG_MIGRATION_EXEC
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#define dprintf(fmt, ...) \
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do { printf("migration-exec: " 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 file_errno(FdMigrationState *s)
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{
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return errno;
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}
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static int file_write(FdMigrationState *s, const void * buf, size_t size)
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{
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return write(s->fd, buf, size);
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}
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static int exec_close(FdMigrationState *s)
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{
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dprintf("exec_close\n");
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if (s->opaque) {
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qemu_fclose(s->opaque);
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s->opaque = NULL;
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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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MigrationState *exec_start_outgoing_migration(const char *command,
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int64_t bandwidth_limit,
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int async)
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{
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FdMigrationState *s;
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FILE *f;
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s = qemu_mallocz(sizeof(*s));
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if (s == NULL) {
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dprintf("Unable to allocate FdMigrationState\n");
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goto err;
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}
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f = popen(command, "w");
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if (f == NULL) {
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dprintf("Unable to popen exec target\n");
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goto err_after_alloc;
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}
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s->fd = fileno(f);
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if (s->fd == -1) {
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dprintf("Unable to retrieve file descriptor for popen'd handle\n");
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goto err_after_open;
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}
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if (fcntl(s->fd, F_SETFD, O_NONBLOCK) == -1) {
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dprintf("Unable to set nonblocking mode on file descriptor\n");
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goto err_after_open;
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}
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s->opaque = qemu_popen(f, "w");
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s->get_error = file_errno;
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s->write = file_write;
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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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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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migrate_fd_connect(s);
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return &s->mig_state;
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err_after_open:
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pclose(f);
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err_after_alloc:
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qemu_free(s);
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err:
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return NULL;
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}
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int exec_start_incoming_migration(const char *command)
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{
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int ret;
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QEMUFile *f;
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dprintf("Attempting to start an incoming migration\n");
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f = qemu_popen_cmd(command, "r");
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if(f == NULL) {
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dprintf("Unable to apply qemu wrapper to popen file\n");
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return -errno;
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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 err;
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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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vm_start();
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qemu_fclose(f);
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return 0;
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err:
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qemu_fclose(f);
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return -errno;
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}
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