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authoraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2008-11-11 16:46:33 +0000
committeraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2008-11-11 16:46:33 +0000
commit065e281356282f59386272aa50590b566a1809d9 (patch)
tree98f265501e5474327a5138bf9ca38736c15f4b38 /migration-exec.c
parenta74b4d2c23a5da45a5ef9eec18ce00923b6bab15 (diff)
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 <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
Diffstat (limited to 'migration-exec.c')
-rw-r--r--migration-exec.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/migration-exec.c b/migration-exec.c
new file mode 100644
index 000000000..5d0b215fd
--- /dev/null
+++ b/migration-exec.c
@@ -0,0 +1,141 @@
+/*
+ * QEMU live migration
+ *
+ * Copyright IBM, Corp. 2008
+ * Copyright Dell MessageOne 2008
+ *
+ * Authors:
+ * Anthony Liguori <aliguori@us.ibm.com>
+ * Charles Duffy <charles_duffy@messageone.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_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;
+}