I am glad to hear that you are also interested in migration. We will be pleasure
if you find some bugs or suggestion and discuss them together with us.
As I know, the qemu will print some log about the migration failure. It is
same to your patch.
> This adds more traces in the migration code.
>
> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
> ---
>
> Debugging migration lately a lot and this patch helps quite a lot.
> Would it make any use for anyone else? Thanks.
>
>
> ---
> migration.c | 34 +++++++++++-----------------------
> savevm.c | 14 ++++++++------
> trace-events | 10 ++++++++--
> vmstate.c | 2 ++
> 4 files changed, 29 insertions(+), 31 deletions(-)
>
> diff --git a/migration.c b/migration.c
> index 742dd5c..5455d2a 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -26,16 +26,6 @@
> #include "qmp-commands.h"
> #include "trace.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
> -
> enum {
> MIG_STATE_ERROR = -1,
> MIG_STATE_NONE,
> @@ -111,7 +101,7 @@ static void process_incoming_migration_co(void *opaque)
> exit(EXIT_FAILURE);
> }
> qemu_announce_self();
> - DPRINTF("successfully loaded vm state\n");
> + trace_migrate_event("successfully loaded vm state");
>
> bdrv_clear_incoming_migration_all();
> /* Make sure all file formats flush their mutable metadata */
> @@ -300,7 +290,7 @@ static void migrate_fd_cleanup(void *opaque)
> s->cleanup_bh = NULL;
>
> if (s->file) {
> - DPRINTF("closing file\n");
> + trace_migrate_event("closing file");
> qemu_mutex_unlock_iothread();
> qemu_thread_join(&s->thread);
> qemu_mutex_lock_iothread();
> @@ -323,7 +313,7 @@ static void migrate_fd_cleanup(void *opaque)
>
> void migrate_fd_error(MigrationState *s)
> {
> - DPRINTF("setting error state\n");
> + trace_migrate_event("setting error state");
> assert(s->file == NULL);
> s->state = MIG_STATE_ERROR;
> trace_migrate_set_state(MIG_STATE_ERROR);
> @@ -333,7 +323,7 @@ void migrate_fd_error(MigrationState *s)
> static void migrate_fd_cancel(MigrationState *s)
> {
> int old_state ;
> - DPRINTF("cancelling migration\n");
> + trace_migrate_event("cancelling migration");
>
> do {
> old_state = s->state;
> @@ -608,29 +598,28 @@ static void *migration_thread(void *opaque)
> int64_t start_time = initial_time;
> bool old_vm_running = false;
>
> - DPRINTF("beginning savevm\n");
> + trace_migrate_event("beginning savevm");
> qemu_savevm_state_begin(s->file, &s->params);
>
> s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
> migrate_set_state(s, MIG_STATE_SETUP, MIG_STATE_ACTIVE);
>
> - DPRINTF("setup complete\n");
> + trace_migrate_event("setup complete");
>
> while (s->state == MIG_STATE_ACTIVE) {
> int64_t current_time;
> uint64_t pending_size;
>
> if (!qemu_file_rate_limit(s->file)) {
> - DPRINTF("iterate\n");
> + trace_migrate_event("iterate");
> pending_size = qemu_savevm_state_pending(s->file, max_size);
> - DPRINTF("pending size %" PRIu64 " max %" PRIu64 "\n",
> - pending_size, max_size);
> + trace_migrate_pending(pending_size, max_size);
> if (pending_size && pending_size >= max_size) {
> qemu_savevm_state_iterate(s->file);
> } else {
> int ret;
>
> - DPRINTF("done iterating\n");
> + trace_migrate_event("done iterating");
> qemu_mutex_lock_iothread();
> start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
> qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
> @@ -669,9 +658,8 @@ static void *migration_thread(void *opaque)
> s->mbps = time_spent ? (((double) transferred_bytes * 8.0) /
> ((double) time_spent / 1000.0)) / 1000.0 / 1000.0 : -1;
>
> - DPRINTF("transferred %" PRIu64 " time_spent %" PRIu64
> - " bandwidth %g max_size %" PRId64 "\n",
> - transferred_bytes, time_spent, bandwidth, max_size);
> + trace_migrate_transferred(transferred_bytes, time_spent,
> + bandwidth, max_size);
> /* if we haven't sent anything, we don't want to recalculate
> 10000 is a small enough number for our purposes */
> if (s->dirty_bytes_rate && transferred_bytes > 10000) {
> diff --git a/savevm.c b/savevm.c
> index 7329fc5..8e15b7e 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -429,6 +429,7 @@ void vmstate_unregister(DeviceState *dev, const
> VMStateDescription *vmsd,
>
> static int vmstate_load(QEMUFile *f, SaveStateEntry *se, int version_id)
> {
> + trace_vmstate_load(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
> if (!se->vmsd) { /* Old style */
> return se->ops->load_state(f, se->opaque, version_id);
> }
> @@ -437,6 +438,7 @@ static int vmstate_load(QEMUFile *f, SaveStateEntry *se,
> int version_id)
>
> static void vmstate_save(QEMUFile *f, SaveStateEntry *se)
> {
> + trace_vmstate_save(se->idstr, se->vmsd ? se->vmsd->name : "(old)");
> if (!se->vmsd) { /* Old style */
> se->ops->save_state(f, se->opaque);
> return;
> @@ -527,13 +529,13 @@ int qemu_savevm_state_iterate(QEMUFile *f)
> if (qemu_file_rate_limit(f)) {
> return 0;
> }
> - trace_savevm_section_start();
> + trace_savevm_section_start(se->idstr, se->section_id);
> /* Section type */
> qemu_put_byte(f, QEMU_VM_SECTION_PART);
> qemu_put_be32(f, se->section_id);
>
> ret = se->ops->save_live_iterate(f, se->opaque);
> - trace_savevm_section_end(se->section_id);
> + trace_savevm_section_end(se->idstr, se->section_id);
>
> if (ret < 0) {
> qemu_file_set_error(f, ret);
> @@ -565,13 +567,13 @@ void qemu_savevm_state_complete(QEMUFile *f)
> continue;
> }
> }
> - trace_savevm_section_start();
> + trace_savevm_section_start(se->idstr, se->section_id);
> /* Section type */
> qemu_put_byte(f, QEMU_VM_SECTION_END);
> qemu_put_be32(f, se->section_id);
>
> ret = se->ops->save_live_complete(f, se->opaque);
> - trace_savevm_section_end(se->section_id);
> + trace_savevm_section_end(se->idstr, se->section_id);
> if (ret < 0) {
> qemu_file_set_error(f, ret);
> return;
> @@ -584,7 +586,7 @@ void qemu_savevm_state_complete(QEMUFile *f)
> if ((!se->ops || !se->ops->save_state) && !se->vmsd) {
> continue;
> }
> - trace_savevm_section_start();
> + trace_savevm_section_start(se->idstr, se->section_id);
> /* Section type */
> qemu_put_byte(f, QEMU_VM_SECTION_FULL);
> qemu_put_be32(f, se->section_id);
> @@ -598,7 +600,7 @@ void qemu_savevm_state_complete(QEMUFile *f)
> qemu_put_be32(f, se->version_id);
>
> vmstate_save(f, se);
> - trace_savevm_section_end(se->section_id);
> + trace_savevm_section_end(se->idstr, se->section_id);
> }
>
> qemu_put_byte(f, QEMU_VM_EOF);
> diff --git a/trace-events b/trace-events
> index 3713063..525636c 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -1030,8 +1030,11 @@ vmware_scratch_write(uint32_t index, uint32_t value)
> "index %d, value 0x%x"
> vmware_setmode(uint32_t w, uint32_t h, uint32_t bpp) "%dx%d @ %d bpp"
>
> # savevm.c
> -savevm_section_start(void) ""
> -savevm_section_end(unsigned int section_id) "section_id %u"
> +savevm_section_start(const char *id, unsigned int section_id) "%s,
> section_id %u"
> +savevm_section_end(const char *id, unsigned int section_id) "%s, section_id
> %u"
> +vmstate_save(const char *idstr, const char *vmsd_name) "%s, %s"
> +vmstate_load(const char *idstr, const char *vmsd_name) "%s, %s"
> +vmstate_load_field_error(const char *field, int ret) "field \"%s\" load
> failed, ret = %d"
>
> # arch_init.c
> migration_bitmap_sync_start(void) ""
> @@ -1164,6 +1167,9 @@ virtio_ccw_new_device(int cssid, int ssid, int schid,
> int devno, const char *dev
>
> # migration.c
> migrate_set_state(int new_state) "new state %d"
> +migrate_event(const char *str) "%s"
> +migrate_pending(uint64_t size, uint64_t max) "pending size %" PRIu64 " max
> %" PRIu64
> +migrate_transferred(uint64_t tranferred, uint64_t time_spent, double
> bandwidth, uint64_t size) "transferred %" PRIu64 " time_spent %" PRIu64 "
> bandwidth %g max_size %" PRId64
>
> # kvm-all.c
> kvm_ioctl(int type, void *arg) "type 0x%x, arg %p"
> diff --git a/vmstate.c b/vmstate.c
> index d1f5eb0..b689f2f 100644
> --- a/vmstate.c
> +++ b/vmstate.c
> @@ -3,6 +3,7 @@
> #include "migration/qemu-file.h"
> #include "migration/vmstate.h"
> #include "qemu/bitops.h"
> +#include "trace.h"
>
> static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription
> *vmsd,
> void *opaque);
> @@ -73,6 +74,7 @@ int vmstate_load_state(QEMUFile *f, const
> VMStateDescription *vmsd,
>
> }
> if (ret < 0) {
> + trace_vmstate_load_field_error(field->name, ret);
> return ret;
> }
> }
> --
> 1.8.4.rc4
>
>
