Re: [Qemu-devel] [PATCH COLO-Frame v9 03/32] COLO: migrate colo related info to slave

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

On 2015/10/3 2:45, Dr. David Alan Gilbert wrote:
> * zhanghailiang (zhang.zhanghailiang@huawei.com) wrote:
>> We can know if VM in destination should go into COLO mode by refer to
>> the info that been migrated from PVM.
>>
>> We skip this section if colo is not enabled (i.e.
>> migrate_set_capability colo off), so that, It not break compatibility with migration
>> however the --enable-colo/disable-colo on the source/destination;
>>
>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>> Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com>
>> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
>> ---
>>   include/migration/colo.h |  2 ++
>>   migration/Makefile.objs  |  1 +
>>   migration/colo-comm.c    | 54 ++++++++++++++++++++++++++++++++++++++++++++++++
>>   vl.c                     |  3 ++-
>>   4 files changed, 59 insertions(+), 1 deletion(-)
>>   create mode 100644 migration/colo-comm.c
>>
>> diff --git a/include/migration/colo.h b/include/migration/colo.h
>> index c60a590..9b6662d 100644
>> --- a/include/migration/colo.h
>> +++ b/include/migration/colo.h
>> @@ -14,7 +14,9 @@
>>   #define QEMU_COLO_H
>>
>>   #include "qemu-common.h"
>> +#include "migration/migration.h"
>>
>>   bool colo_supported(void);
>> +void colo_info_mig_init(void);
>>
>>   #endif
>> diff --git a/migration/Makefile.objs b/migration/Makefile.objs
>> index 5a25d39..cb7bd30 100644
>> --- a/migration/Makefile.objs
>> +++ b/migration/Makefile.objs
>> @@ -1,5 +1,6 @@
>>   common-obj-y += migration.o tcp.o
>>   common-obj-$(CONFIG_COLO) += colo.o
>> +common-obj-y += colo-comm.o
>>   common-obj-y += vmstate.o
>>   common-obj-y += qemu-file.o qemu-file-buf.o qemu-file-unix.o qemu-file-stdio.o
>>   common-obj-y += xbzrle.o
>> diff --git a/migration/colo-comm.c b/migration/colo-comm.c
>> new file mode 100644
>> index 0000000..4330bd8
>> --- /dev/null
>> +++ b/migration/colo-comm.c
>> @@ -0,0 +1,54 @@
>> +/*
>> + * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
>> + * (a.k.a. Fault Tolerance or Continuous Replication)
>> + *
>> + * Copyright (c) 2015 HUAWEI TECHNOLOGIES CO., LTD.
>> + * Copyright (c) 2015 FUJITSU LIMITED
>> + * Copyright (c) 2015 Intel Corporation
>> + *
>> + * This work is licensed under the terms of the GNU GPL, version 2 or
>> + * later. See the COPYING file in the top-level directory.
>> + *
>> + */
>> +
>> +#include <migration/colo.h>
>> +#include "trace.h"
>> +
>> +typedef struct {
>> +     uint32_t colo_requested;
>> +} COLOInfo;
>> +
>> +static COLOInfo colo_info;
>> +
>> +static void colo_info_pre_save(void *opaque)
>> +{
>> +    COLOInfo *s = opaque;
>> +
>> +    if (migrate_enable_colo()) {
>> +        s->colo_requested = 1;
>> +    } else {
>> +        s->colo_requested = 0;
>> +    }
>> +}
>> +
>> +static bool colo_info_need(void *opaque)
>> +{
>> +   return migrate_enable_colo();
>> +}
>> +
>> +static const VMStateDescription colo_state = {
>> +     .name = "COLOState",
>> +     .version_id = 1,
>> +     .minimum_version_id = 1,
>> +     .pre_save = colo_info_pre_save,
>> +     .needed = colo_info_need,
>> +     .fields = (VMStateField[]) {
>> +         VMSTATE_UINT32(colo_requested, COLOInfo),
>
> Any reason not to do it as a bool, and use VMSTATE_BOOL?
> (That would also simplify the pre_save).
>

No special reason, use VMSTATE_BOOL is a good idea, will fix
in next version, thanks.

zhanghailiang
> (Oddly you don't actually need the state at all - just
> the presence of the section is enough, but I don't worry
> about that).
>
> Dave
>
>> +         VMSTATE_END_OF_LIST()
>> +        },
>> +};
>> +
>> +void colo_info_mig_init(void)
>> +{
>> +    vmstate_register(NULL, 0, &colo_state, &colo_info);
>> +}
>> diff --git a/vl.c b/vl.c
>> index aee931a..571347a 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -92,6 +92,7 @@ int main(int argc, char **argv)
>>   #include "sysemu/dma.h"
>>   #include "audio/audio.h"
>>   #include "migration/migration.h"
>> +#include "migration/colo.h"
>>   #include "sysemu/kvm.h"
>>   #include "qapi/qmp/qjson.h"
>>   #include "qemu/option.h"
>> @@ -4446,7 +4447,7 @@ int main(int argc, char **argv, char **envp)
>>
>>       blk_mig_init();
>>       ram_mig_init();
>> -
>> +    colo_info_mig_init();
>>       /* If the currently selected machine wishes to override the units-per-bus
>>        * property of its default HBA interface type, do so now. */
>>       if (machine_class->units_per_default_bus) {
>> --
>> 1.8.3.1
>>
>>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>
> .
>