* zhanghailiang (zhang.zhanghaili...@huawei.com) wrote:
> We separate the process of saving/loading ram and device state when do
> checkpoint, we add new helpers for save/load ram/device. With this change,
> we can directly transfer ram from master to slave without using
> QEMUSizeBufferas as assistant, which also reduce the size of extra memory
> been used during checkpoint.
>
> Besides, we move the colo_flush_ram_cache to the proper position after the
> above change.
>
> Signed-off-by: zhanghailiang <zhang.zhanghaili...@huawei.com>
> Signed-off-by: Li Zhijian <lizhij...@cn.fujitsu.com>
> ---
> v14:
> - split two new patches from this patch
> - Some minor fixes from Dave
> v13:
> - Re-use some existed helper functions to realize saving/loading
> ram and device.
> v11:
> - Remove load configuration section in qemu_loadvm_state_begin()
> ---
> migration/colo.c | 48 ++++++++++++++++++++++++++++++++++++++----------
> migration/ram.c | 5 -----
> migration/savevm.c | 5 +++++
> 3 files changed, 43 insertions(+), 15 deletions(-)
>
> diff --git a/migration/colo.c b/migration/colo.c
> index 16bada6..300fa54 100644
> --- a/migration/colo.c
> +++ b/migration/colo.c
> @@ -288,21 +288,37 @@ static int
> colo_do_checkpoint_transaction(MigrationState *s,
> goto out;
> }
>
> + colo_put_cmd(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err);
> + if (local_err) {
> + goto out;
> + }
> +
> /* Disable block migration */
> s->params.blk = 0;
> s->params.shared = 0;
> - qemu_savevm_state_header(trans);
> - qemu_savevm_state_begin(trans, &s->params);
> + qemu_savevm_state_begin(s->to_dst_file, &s->params);
> + ret = qemu_file_get_error(s->to_dst_file);
> + if (ret < 0) {
> + error_report("Save vm state begin error");
> + goto out;
> + }
> +
> qemu_mutex_lock_iothread();
> - qemu_savevm_state_complete_precopy(trans, false);
> + /*
> + * Only save VM's live state, which not including device state.
> + * TODO: We may need a timeout mechanism to prevent COLO process
> + * to be blocked here.
> + */
> + qemu_savevm_live_state(s->to_dst_file);
> + /* Note: device state is saved into buffer */
> + ret = qemu_save_device_state(trans);
> qemu_mutex_unlock_iothread();
Yes, I still worry a little about what can hang under that lock, but I think
it's the best we've got at the moment; we probably need to understand what
the rules are about what actually needs the lock!
Other than that,
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> -
> - qemu_fflush(trans);
> -
> - colo_put_cmd(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err);
> - if (local_err) {
> + if (ret < 0) {
> + error_report("Save device state error");
> goto out;
> }
> + qemu_fflush(trans);
> +
> /* we send the total size of the vmstate first */
> size = qsb_get_length(buffer);
> colo_put_cmd_value(s->to_dst_file, COLO_MESSAGE_VMSTATE_SIZE,
> @@ -573,6 +589,16 @@ void *colo_process_incoming_thread(void *opaque)
> goto out;
> }
>
> + ret = qemu_loadvm_state_begin(mis->from_src_file);
> + if (ret < 0) {
> + error_report("Load vm state begin error, ret=%d", ret);
> + goto out;
> + }
> + ret = qemu_loadvm_state_main(mis->from_src_file, mis);
> + if (ret < 0) {
> + error_report("Load VM's live state (ram) error");
> + goto out;
> + }
> /* read the VM state total size first */
> value = colo_get_cmd_value(mis->from_src_file,
> COLO_MESSAGE_VMSTATE_SIZE, &local_err);
> @@ -605,8 +631,10 @@ void *colo_process_incoming_thread(void *opaque)
> qemu_mutex_lock_iothread();
> qemu_system_reset(VMRESET_SILENT);
> vmstate_loading = true;
> - if (qemu_loadvm_state(fb) < 0) {
> - error_report("COLO: loadvm failed");
> + colo_flush_ram_cache();
> + ret = qemu_load_device_state(fb);
> + if (ret < 0) {
> + error_report("COLO: load device state failed");
> qemu_mutex_unlock_iothread();
> goto out;
> }
> diff --git a/migration/ram.c b/migration/ram.c
> index 891f3b2..8f416d5 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -2465,7 +2465,6 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> * be atomic
> */
> bool postcopy_running = postcopy_state_get() >=
> POSTCOPY_INCOMING_LISTENING;
> - bool need_flush = false;
>
> seq_iter++;
>
> @@ -2500,7 +2499,6 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
> /* After going into COLO, we should load the Page into
> colo_cache */
> if (ram_cache_enable) {
> host = colo_cache_from_block_offset(block, addr);
> - need_flush = true;
> } else {
> host = host_from_ram_block_offset(block, addr);
> }
> @@ -2594,9 +2592,6 @@ static int ram_load(QEMUFile *f, void *opaque, int
> version_id)
>
> rcu_read_unlock();
>
> - if (!ret && ram_cache_enable && need_flush) {
> - colo_flush_ram_cache();
> - }
> DPRINTF("Completed load of VM with exit code %d seq iteration "
> "%" PRIu64 "\n", ret, seq_iter);
> return ret;
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 60c7b57..1551fbb 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -50,6 +50,7 @@
> #include "qemu/iov.h"
> #include "block/snapshot.h"
> #include "block/qapi.h"
> +#include "migration/colo.h"
>
>
> #ifndef ETH_P_RARP
> @@ -923,6 +924,10 @@ void qemu_savevm_state_begin(QEMUFile *f,
> break;
> }
> }
> + if (migration_in_colo_state()) {
> + qemu_put_byte(f, QEMU_VM_EOF);
> + qemu_fflush(f);
> + }
> }
>
> /*
> --
> 1.8.3.1
>
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
