Jules Wang <junqing.w...@cs2c.com.cn> wrote:
> By leveraging live migration feature, the sender simply starts a
> new migration when the previous migration is completed.
>
> We need to handle the variables related to live migration very
> carefully. So the new migration does not restart from the very
> begin of the migration, instead, it continues the previous
> migration.
>
> Signed-off-by: Jules Wang <junqing.w...@cs2c.com.cn>
> ---
> arch_init.c | 18 +++++++++++++-----
> migration.c | 23 ++++++++++++++++++++++-
> savevm.c | 4 ++++
> 3 files changed, 39 insertions(+), 6 deletions(-)
>
> diff --git a/arch_init.c b/arch_init.c
> index e47e139..5d006f6 100644
> --- a/arch_init.c
> +++ b/arch_init.c
> @@ -611,10 +611,14 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
> {
> RAMBlock *block;
> int64_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS;
> + bool create = false;
This variable is never set.
>
> - migration_bitmap = bitmap_new(ram_pages);
> - bitmap_set(migration_bitmap, 0, ram_pages);
> - migration_dirty_pages = ram_pages;
> + if (!ft_enabled() || !migration_bitmap) {
> + migration_bitmap = bitmap_new(ram_pages);
Nothing in this patch sets the migration_bitmap to anything.
> + bitmap_set(migration_bitmap, 0, ram_pages);
> + migration_dirty_pages = ram_pages;
> + create = true;
> + }
> mig_throttle_on = false;
> dirty_rate_high_cnt = 0;
> @@ -634,7 +638,9 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
> qemu_mutex_lock_iothread();
> qemu_mutex_lock_ramlist();
> bytes_transferred = 0;
> - reset_ram_globals();
> + if (!ft_enabled() || create) {
> + reset_ram_globals();
> + }
>
> memory_global_dirty_log_start();
> migration_bitmap_sync();
> @@ -744,7 +750,9 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
> }
>
> ram_control_after_iterate(f, RAM_CONTROL_FINISH);
> - migration_end();
> + if (!ft_enabled()) {
> + migration_end();
> + }
What you want here? My guess is that you want to sent device state
without sending the end of migration command, right?
> qemu_mutex_unlock_ramlist();
> qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
> diff --git a/migration.c b/migration.c
> index 59c8f32..d8a9b2d 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -567,6 +567,7 @@ static void *migration_thread(void *opaque)
> int64_t max_size = 0;
> int64_t start_time = initial_time;
> bool old_vm_running = false;
> + int time_window = 100;
>
> DPRINTF("beginning savevm\n");
> qemu_savevm_state_begin(s->file, &s->params);
> @@ -578,6 +579,8 @@ static void *migration_thread(void *opaque)
>
> while (s->state == MIG_STATE_ACTIVE) {
> int64_t current_time;
> + int64_t time_spent;
> + int64_t migration_start_time =
> qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
> uint64_t pending_size;
>
> if (!qemu_file_rate_limit(s->file)) {
> @@ -607,10 +610,28 @@ static void *migration_thread(void *opaque)
> break;
> }
>
> - if (!qemu_file_get_error(s->file)) {
> + if (!qemu_file_get_error(s->file) && !ft_enabled()) {
> migrate_set_state(s, MIG_STATE_ACTIVE,
> MIG_STATE_COMPLETED);
> break;
> }
> +
> + if (ft_enabled()) {
> + if (old_vm_running) {
> + qemu_mutex_lock_iothread();
> + vm_start();
> + qemu_mutex_unlock_iothread();
> +
> + current_time =
> qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
> + time_spent = current_time - migration_start_time;
> + DPRINTF("this migration lasts for %" PRId64 "ms\n",
> + time_spent);
> + if (time_spent < time_window) {
> + g_usleep((time_window - time_spent)*1000);
Why are we waiting here? If we are migration faster than allowed, why
we are waiting?
> + initial_time += time_window - time_spent;
> + }
> + }
> + qemu_savevm_state_begin(s->file, &s->params);
> + }
> }
> }
>
> diff --git a/savevm.c b/savevm.c
> index c536aa4..6daf690 100644
> --- a/savevm.c
> +++ b/savevm.c
> @@ -1824,6 +1824,7 @@ static void vmstate_save(QEMUFile *f, SaveStateEntry
> *se)
> #define QEMU_VM_SECTION_END 0x03
> #define QEMU_VM_SECTION_FULL 0x04
> #define QEMU_VM_SUBSECTION 0x05
> +#define QEMU_VM_EOF_MAGIC 0xFeedCafe
>
> bool qemu_savevm_state_blocked(Error **errp)
> {
> @@ -1983,6 +1984,9 @@ void qemu_savevm_state_complete(QEMUFile *f)
> }
>
> qemu_put_byte(f, QEMU_VM_EOF);
> + if (ft_enabled()) {
> + qemu_put_be32(f, QEMU_VM_EOF_MAGIC);
> + }
> qemu_fflush(f);
> }
