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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.c
parenttarget-alpha: fix decoding of CVTST /S (diff)
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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.c')
-rw-r--r--migration.c178
1 files changed, 178 insertions, 0 deletions
diff --git a/migration.c b/migration.c
index 9e6c43731..0ef777add 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);
+}