Re: [Qemu-devel] [PATCH 15/18] migration: adjust migration_thread for local migration

[Paolo Bonzini <pbonzini@redhat.com>]

Il 21/08/2013 09:18, Lei Li ha scritto:
> Integrate localhost migration thread to migration_thread. As the mechanism
> of local migration is different than the current migration, and it does
> not need to do iterate.
> 
> So the whole thread can split into two stages, it will send all the ram
> pages in qemu_savevm_state_begin stage, and send the device states in
> qemu_save_device_state stage.

This is not needed.  Skipping the iteration should happen automatically
if you stop the VM before invoking migration.

Paolo

> Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
> ---
>  migration.c |   73 ++++++++++++++++++++++++++++++++++++----------------------
>  1 files changed, 45 insertions(+), 28 deletions(-)
> 
> diff --git a/migration.c b/migration.c
> index 2f85358..2471664 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -565,37 +565,54 @@ static void *migration_thread(void *opaque)
>      while (s->state == MIG_STATE_ACTIVE) {
>          int64_t current_time;
>          uint64_t pending_size;
> +        int ret;
>  
> -        if (!qemu_file_rate_limit(s->file)) {
> -            DPRINTF("iterate\n");
> -            pending_size = qemu_savevm_state_pending(s->file, max_size);
> -            DPRINTF("pending size %lu max %lu\n", pending_size, max_size);
> -            if (pending_size && pending_size >= max_size) {
> -                qemu_savevm_state_iterate(s->file);
> -            } else {
> -                int ret;
> -
> -                DPRINTF("done iterating\n");
> -                qemu_mutex_lock_iothread();
> -                start_time = qemu_get_clock_ms(rt_clock);
> -                qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
> -                old_vm_running = runstate_is_running();
> -
> -                ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
> -                if (ret >= 0) {
> -                    qemu_file_set_rate_limit(s->file, INT_MAX);
> -                    qemu_savevm_state_complete(s->file);
> -                }
> -                qemu_mutex_unlock_iothread();
> +        if (s->enabled_capabilities[MIGRATION_CAPABILITY_LOCALHOST]) {
> +            DPRINTF("local migration start\n");
>  
> -                if (ret < 0) {
> -                    migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR);
> -                    break;
> -                }
> +            ret = qemu_save_device_state(s->file);
> +            if (ret < 0) {
> +                migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR);
> +                break;
> +            }
>  
> -                if (!qemu_file_get_error(s->file)) {
> -                    migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_COMPLETED);
> -                    break;
> +            if (!qemu_file_get_error(s->file)) {
> +                DPRINTF("local migration completed\n");
> +                migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_COMPLETED);
> +                break;
> +            }
> +        } else {
> +            if (!qemu_file_rate_limit(s->file)) {
> +                DPRINTF("iterate\n");
> +                pending_size = qemu_savevm_state_pending(s->file, max_size);
> +                DPRINTF("pending size %lu max %lu\n", pending_size, max_size);
> +                if (pending_size && pending_size >= max_size) {
> +                    qemu_savevm_state_iterate(s->file);
> +                } else {
> +                    int ret;
> +
> +                    DPRINTF("done iterating\n");
> +                    qemu_mutex_lock_iothread();
> +                    start_time = qemu_get_clock_ms(rt_clock);
> +                    qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
> +                    old_vm_running = runstate_is_running();
> +
> +                    ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
> +                    if (ret >= 0) {
> +                        qemu_file_set_rate_limit(s->file, INT_MAX);
> +                        qemu_savevm_state_complete(s->file);
> +                    }
> +                    qemu_mutex_unlock_iothread();
> +
> +                    if (ret < 0) {
> +                        migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_ERROR);
> +                        break;
> +                    }
> +
> +                    if (!qemu_file_get_error(s->file)) {
> +                        migrate_set_state(s, MIG_STATE_ACTIVE, MIG_STATE_COMPLETED);
> +                        break;
> +                    }
>                  }
>              }
>          }
>