[Qemu-devel] [PATCH COLO-Frame v18 00/34] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service (FT)

[Qemu-devel] [PATCH COLO-Frame v18 00/34] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service (FT)

[zhanghailiang]

This is the 18th version of COLO FT feature.

It is based on '[PATCH v24 00/12] Block replication for continuous checkpoints' series.
The complete codes can be found from the link:
https://github.com/coloft/qemu/commits/colo-v3.1-periodic-mode

For block part, Stefan promised to merge it.
So we would like to update this series to the latest upstream.

For this series, only patch 32 ~ 34 are not reviewed, so
please help review them. Thanks.

Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>

TODO:
1. Checkpoint based on proxy in qemu
2. The capability of continuous FT
3. Optimize the VM's downtime during checkpoint

zhanghailiang (34):
  configure: Add parameter for configure to enable/disable COLO support
  migration: Introduce capability 'x-colo' to migration
  COLO: migrate colo related info to secondary node
  migration: Integrate COLO checkpoint process into migration
  migration: Integrate COLO checkpoint process into loadvm
  COLO/migration: Create a new communication path from destination to
    source
  COLO: Implement COLO checkpoint protocol
  COLO: Add a new RunState RUN_STATE_COLO
  COLO: Save PVM state to secondary side when do checkpoint
  COLO: Load PVM's dirty pages into SVM's RAM cache temporarily
  ram/COLO: Record the dirty pages that SVM received
  COLO: Load VMState into buffer before restore it
  COLO: Flush PVM's cached RAM into SVM's memory
  COLO: Add checkpoint-delay parameter for migrate-set-parameters
  COLO: Synchronize PVM's state to SVM periodically
  COLO failover: Introduce a new command to trigger a failover
  COLO failover: Introduce state to record failover process
  COLO: Implement failover work for Primary VM
  COLO: Implement failover work for Secondary VM
  qmp event: Add COLO_EXIT event to notify users while exited from COLO
  COLO failover: Shutdown related socket fd when do failover
  COLO failover: Don't do failover during loading VM's state
  COLO: Process shutdown command for VM in COLO state
  COLO: Update the global runstate after going into colo state
  savevm: Introduce two helper functions for save/find loadvm_handlers
    entry
  migration/savevm: Add new helpers to process the different stages of
    loadvm
  migration/savevm: Export two helper functions for savevm process
  COLO: Separate the process of saving/loading ram and device state
  COLO: Split qemu_savevm_state_begin out of checkpoint process
  filter-buffer: Accept zero interval
  net: Add notifier/callback for netdev init
  COLO/filter: Add each netdev a buffer filter
  COLO: Control the status of buffer filters for PVM
  COLO: Add block replication into colo process

 configure                     |  11 +
 docs/qmp-events.txt           |  16 +
 hmp-commands.hx               |  15 +
 hmp.c                         |  15 +
 hmp.h                         |   1 +
 include/exec/ram_addr.h       |   1 +
 include/migration/colo.h      |  43 +++
 include/migration/failover.h  |  33 ++
 include/migration/migration.h |  16 +
 include/net/filter.h          |   2 +
 include/net/net.h             |   3 +
 include/sysemu/sysemu.h       |   9 +
 migration/Makefile.objs       |   2 +
 migration/colo-comm.c         |  79 ++++
 migration/colo-failover.c     |  84 +++++
 migration/colo.c              | 844 ++++++++++++++++++++++++++++++++++++++++++
 migration/migration.c         |  84 ++++-
 migration/ram.c               | 175 ++++++++-
 migration/savevm.c            | 113 ++++--
 migration/trace-events        |   8 +
 net/filter-buffer.c           |  12 -
 net/net.c                     |  12 +
 qapi-schema.json              | 102 ++++-
 qapi/event.json               |  15 +
 qmp-commands.hx               |  24 +-
 stubs/Makefile.objs           |   1 +
 stubs/migration-colo.c        |  55 +++
 vl.c                          |  30 +-
 28 files changed, 1744 insertions(+), 61 deletions(-)
 create mode 100644 include/migration/colo.h
 create mode 100644 include/migration/failover.h
 create mode 100644 migration/colo-comm.c
 create mode 100644 migration/colo-failover.c
 create mode 100644 migration/colo.c
 create mode 100644 stubs/migration-colo.c

-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 01/34] configure: Add parameter for configure to enable/disable COLO support

[zhanghailiang]

configure --enable-colo/--disable-colo to switch COLO
support on/off.
COLO support is On by default.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v11:
- Turn COLO on in default (Eric's suggestion)
---
 configure | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/configure b/configure
index 3615390..78fda7d 100755
--- a/configure
+++ b/configure
@@ -230,6 +230,7 @@ xfs=""
 vhost_net="no"
 vhost_scsi="no"
 kvm="no"
+colo="yes"
 rdma=""
 gprof="no"
 debug_tcg="no"
@@ -919,6 +920,10 @@ for opt do
   ;;
   --enable-kvm) kvm="yes"
   ;;
+  --disable-colo) colo="no"
+  ;;
+  --enable-colo) colo="yes"
+  ;;
   --disable-tcg-interpreter) tcg_interpreter="no"
   ;;
   --enable-tcg-interpreter) tcg_interpreter="yes"
@@ -1356,6 +1361,7 @@ disabled with --disable-FEATURE, default is enabled if available:
   fdt             fdt device tree
   bluez           bluez stack connectivity
   kvm             KVM acceleration support
+  colo            COarse-grain LOck-stepping VM for Non-stop Service
   rdma            RDMA-based migration support
   uuid            uuid support
   vde             support for vde network
@@ -4857,6 +4863,7 @@ echo "Linux AIO support $linux_aio"
 echo "ATTR/XATTR support $attr"
 echo "Install blobs     $blobs"
 echo "KVM support       $kvm"
+echo "COLO support      $colo"
 echo "RDMA support      $rdma"
 echo "TCG interpreter   $tcg_interpreter"
 echo "fdt support       $fdt"
@@ -5468,6 +5475,10 @@ if have_backend "ftrace"; then
 fi
 echo "CONFIG_TRACE_FILE=$trace_file" >> $config_host_mak
 
+if test "$colo" = "yes"; then
+  echo "CONFIG_COLO=y" >> $config_host_mak
+fi
+
 if test "$rdma" = "yes" ; then
   echo "CONFIG_RDMA=y" >> $config_host_mak
 fi
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH COLO-Frame v18 01/34] configure: Add parameter for configure to enable/disable COLO support

[Amit Shah]

On (Wed) 03 Aug 2016 [20:25:39], zhanghailiang wrote:
> configure --enable-colo/--disable-colo to switch COLO
> support on/off.
> COLO support is On by default.

Can you please make this the last patch in the series - so we get the
code in before we add in the config option?  Better for bisection, but
also for a logical flow.

Thanks,

                Amit

Re: [Qemu-devel] [PATCH COLO-Frame v18 01/34] configure: Add parameter for configure to enable/disable COLO support

[Hailiang Zhang]

Hi Amit，

On 2016/8/26 5:45, Amit Shah wrote:
> On (Wed) 03 Aug 2016 [20:25:39], zhanghailiang wrote:
>> configure --enable-colo/--disable-colo to switch COLO
>> support on/off.
>> COLO support is On by default.
>
> Can you please make this the last patch in the series - so we get the
> code in before we add in the config option?  Better for bisection, but
> also for a logical flow.
>

I have moved it to the end of the series, please see the new version.

Thanks.
Hailiang

> Thanks,
>
>                  Amit
>
> .
>

[Qemu-devel] [PATCH COLO-Frame v18 02/34] migration: Introduce capability 'x-colo' to migration

[zhanghailiang]

We add helper function colo_supported() to indicate whether
colo is supported or not, with which we use to control whether or not
showing 'x-colo' string to users, they can use qmp command
'query-migrate-capabilities' or hmp command 'info migrate_capabilities'
to learn if colo is supported.

Cc: Juan Quintela <quintela@redhat.com>
Cc: Amit Shah <amit.shah@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
v16:
- fix compile broken due to missing osdep.h
v14:
- Fix the date of Copyright to 2016
v10:
- Rename capability 'colo' to experimental 'x-colo' (Eric's suggestion).
- Rename migrate_enable_colo() to migrate_colo_enabled() (Eric's suggestion).
---
 include/migration/colo.h      | 20 ++++++++++++++++++++
 include/migration/migration.h |  1 +
 migration/Makefile.objs       |  1 +
 migration/colo.c              | 19 +++++++++++++++++++
 migration/migration.c         | 18 ++++++++++++++++++
 qapi-schema.json              |  6 +++++-
 qmp-commands.hx               |  2 +-
 stubs/Makefile.objs           |  1 +
 stubs/migration-colo.c        | 19 +++++++++++++++++++
 9 files changed, 85 insertions(+), 2 deletions(-)
 create mode 100644 include/migration/colo.h
 create mode 100644 migration/colo.c
 create mode 100644 stubs/migration-colo.c

diff --git a/include/migration/colo.h b/include/migration/colo.h
new file mode 100644
index 0000000..59a632a
--- /dev/null
+++ b/include/migration/colo.h
@@ -0,0 +1,20 @@
+/*
+ * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ * (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 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.
+ */
+
+#ifndef QEMU_COLO_H
+#define QEMU_COLO_H
+
+#include "qemu-common.h"
+
+bool colo_supported(void);
+
+#endif
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 3c96623..5effc05 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -301,6 +301,7 @@ int xbzrle_decode_buffer(uint8_t *src, int slen, uint8_t *dst, int dlen);
 
 int migrate_use_xbzrle(void);
 int64_t migrate_xbzrle_cache_size(void);
+bool migrate_colo_enabled(void);
 
 int64_t xbzrle_cache_resize(int64_t new_size);
 
diff --git a/migration/Makefile.objs b/migration/Makefile.objs
index 30ad945..cff96f0 100644
--- a/migration/Makefile.objs
+++ b/migration/Makefile.objs
@@ -1,5 +1,6 @@
 common-obj-y += migration.o socket.o fd.o exec.o
 common-obj-y += tls.o
+common-obj-$(CONFIG_COLO) += colo.o
 common-obj-y += vmstate.o
 common-obj-y += qemu-file.o
 common-obj-y += qemu-file-channel.o
diff --git a/migration/colo.c b/migration/colo.c
new file mode 100644
index 0000000..5749016
--- /dev/null
+++ b/migration/colo.c
@@ -0,0 +1,19 @@
+/*
+ * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ * (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 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 "qemu/osdep.h"
+#include "migration/colo.h"
+
+bool colo_supported(void)
+{
+    return true;
+}
diff --git a/migration/migration.c b/migration/migration.c
index 955d5ee..17f0f75 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -36,6 +36,7 @@
 #include "exec/address-spaces.h"
 #include "io/channel-buffer.h"
 #include "io/channel-tls.h"
+#include "migration/colo.h"
 
 #define MAX_THROTTLE  (32 << 20)      /* Migration transfer speed throttling */
 
@@ -537,6 +538,9 @@ MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
 
     caps = NULL; /* silence compiler warning */
     for (i = 0; i < MIGRATION_CAPABILITY__MAX; i++) {
+        if (i == MIGRATION_CAPABILITY_X_COLO && !colo_supported()) {
+            continue;
+        }
         if (head == NULL) {
             head = g_malloc0(sizeof(*caps));
             caps = head;
@@ -728,6 +732,14 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
     }
 
     for (cap = params; cap; cap = cap->next) {
+        if (cap->value->capability == MIGRATION_CAPABILITY_X_COLO) {
+            if (!colo_supported()) {
+                error_setg(errp, "COLO is not currently supported, please"
+                             " configure with --enable-colo option in order to"
+                             " support COLO feature");
+                continue;
+            }
+        }
         s->enabled_capabilities[cap->value->capability] = cap->value->state;
     }
 
@@ -1696,6 +1708,12 @@ fail:
                       MIGRATION_STATUS_FAILED);
 }
 
+bool migrate_colo_enabled(void)
+{
+    MigrationState *s = migrate_get_current();
+    return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO];
+}
+
 /*
  * Master migration thread on the source VM.
  * It drives the migration and pumps the data down the outgoing channel.
diff --git a/qapi-schema.json b/qapi-schema.json
index 5658723..cdab6cf 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -553,11 +553,15 @@
 #          been migrated, pulling the remaining pages along as needed. NOTE: If
 #          the migration fails during postcopy the VM will fail.  (since 2.6)
 #
+# @x-colo: If enabled, migration will never end, and the state of the VM on the
+#        primary side will be migrated continuously to the VM on secondary
+#        side. (since 2.8)
+#
 # Since: 1.2
 ##
 { 'enum': 'MigrationCapability',
   'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',
-           'compress', 'events', 'postcopy-ram'] }
+           'compress', 'events', 'postcopy-ram', 'x-colo'] }
 
 ##
 # @MigrationCapabilityStatus
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 1176056..6a470d3 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3752,7 +3752,7 @@ Query current migration capabilities
          - "zero-blocks" : Zero Blocks state (json-bool)
          - "compress": Multiple compression threads state (json-bool)
          - "events": Migration state change event state (json-bool)
-         - "postcopy-ram": postcopy ram state (json-bool)
+         - "x-colo" : COarse-Grain LOck Stepping for Non-stop Service (json-bool)
 
 Arguments:
 
diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
index 55edd15..3b867d8 100644
--- a/stubs/Makefile.objs
+++ b/stubs/Makefile.objs
@@ -45,3 +45,4 @@ stub-obj-y += iohandler.o
 stub-obj-y += smbios_type_38.o
 stub-obj-y += ipmi.o
 stub-obj-y += pc_madt_cpu_entry.o
+stub-obj-y += migration-colo.o
diff --git a/stubs/migration-colo.c b/stubs/migration-colo.c
new file mode 100644
index 0000000..d215057
--- /dev/null
+++ b/stubs/migration-colo.c
@@ -0,0 +1,19 @@
+/*
+ * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ * (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 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 "qemu/osdep.h"
+#include "migration/colo.h"
+
+bool colo_supported(void)
+{
+    return false;
+}
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH COLO-Frame v18 02/34] migration: Introduce capability 'x-colo' to migration

[Amit Shah]

On (Wed) 03 Aug 2016 [20:25:40], zhanghailiang wrote:
> We add helper function colo_supported() to indicate whether
> colo is supported or not, with which we use to control whether or not
> showing 'x-colo' string to users, they can use qmp command
> 'query-migrate-capabilities' or hmp command 'info migrate_capabilities'
> to learn if colo is supported.
> 
> Cc: Juan Quintela <quintela@redhat.com>
> Cc: Amit Shah <amit.shah@redhat.com>
> Cc: Eric Blake <eblake@redhat.com>
> Cc: Markus Armbruster <armbru@redhat.com>
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>


> +#include "qemu/osdep.h"
> +#include "migration/colo.h"
> +
> +bool colo_supported(void)
> +{
> +    return true;
> +}

Can you start with this disabled, and returning true when all the
pieces are done (ie close to the patches when the functionality is
actually useful later in the series?).

Re: [Qemu-devel] [PATCH COLO-Frame v18 02/34] migration: Introduce capability 'x-colo' to migration

[Hailiang Zhang]

On 2016/8/26 5:47, Amit Shah wrote:
> On (Wed) 03 Aug 2016 [20:25:40], zhanghailiang wrote:
>> We add helper function colo_supported() to indicate whether
>> colo is supported or not, with which we use to control whether or not
>> showing 'x-colo' string to users, they can use qmp command
>> 'query-migrate-capabilities' or hmp command 'info migrate_capabilities'
>> to learn if colo is supported.
>>
>> Cc: Juan Quintela <quintela@redhat.com>
>> Cc: Amit Shah <amit.shah@redhat.com>
>> Cc: Eric Blake <eblake@redhat.com>
>> Cc: Markus Armbruster <armbru@redhat.com>
>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
>> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>
>
>> +#include "qemu/osdep.h"
>> +#include "migration/colo.h"
>> +
>> +bool colo_supported(void)
>> +{
>> +    return true;
>> +}
>
> Can you start with this disabled, and returning true when all the
> pieces are done (ie close to the patches when the functionality is
> actually useful later in the series?).
>

Yes, i have done as your advise, please see the new version, thanks.

> .
>

[Qemu-devel] [PATCH COLO-Frame v18 03/34] COLO: migrate colo related info to secondary node

[zhanghailiang]

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: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v16:
- Fix compile broken due to missing osdep.h
v14:
- Adjust the place of calling colo_info_init()
v11:
- Add Reviewed-by tag
v10:
- Use VMSTATE_BOOL instead of VMSTATE_UNIT32 for 'colo_requested' (Dave's suggestion)
---
 include/migration/colo.h |  2 ++
 migration/Makefile.objs  |  1 +
 migration/colo-comm.c    | 51 ++++++++++++++++++++++++++++++++++++++++++++++++
 vl.c                     |  3 +++
 4 files changed, 57 insertions(+)
 create mode 100644 migration/colo-comm.c

diff --git a/include/migration/colo.h b/include/migration/colo.h
index 59a632a..1c899a0 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_init(void);
 
 #endif
diff --git a/migration/Makefile.objs b/migration/Makefile.objs
index cff96f0..4bbe9ab 100644
--- a/migration/Makefile.objs
+++ b/migration/Makefile.objs
@@ -1,6 +1,7 @@
 common-obj-y += migration.o socket.o fd.o exec.o
 common-obj-y += tls.o
 common-obj-$(CONFIG_COLO) += colo.o
+common-obj-y += colo-comm.o
 common-obj-y += vmstate.o
 common-obj-y += qemu-file.o
 common-obj-y += qemu-file-channel.o
diff --git a/migration/colo-comm.c b/migration/colo-comm.c
new file mode 100644
index 0000000..2d06ace
--- /dev/null
+++ b/migration/colo-comm.c
@@ -0,0 +1,51 @@
+/*
+ * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ * (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 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 "qemu/osdep.h"
+#include <migration/colo.h>
+#include "trace.h"
+
+typedef struct {
+     bool colo_requested;
+} COLOInfo;
+
+static COLOInfo colo_info;
+
+static void colo_info_pre_save(void *opaque)
+{
+    COLOInfo *s = opaque;
+
+    s->colo_requested = migrate_colo_enabled();
+}
+
+static bool colo_info_need(void *opaque)
+{
+   return migrate_colo_enabled();
+}
+
+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_BOOL(colo_requested, COLOInfo),
+         VMSTATE_END_OF_LIST()
+        },
+};
+
+void colo_info_init(void)
+{
+    vmstate_register(NULL, 0, &colo_state, &colo_info);
+}
diff --git a/vl.c b/vl.c
index e7c2c62..097295d 100644
--- a/vl.c
+++ b/vl.c
@@ -89,6 +89,7 @@ int main(int argc, char **argv)
 #include "audio/audio.h"
 #include "migration/migration.h"
 #include "sysemu/cpus.h"
+#include "migration/colo.h"
 #include "sysemu/kvm.h"
 #include "qapi/qmp/qjson.h"
 #include "qemu/option.h"
@@ -4354,6 +4355,8 @@ int main(int argc, char **argv, char **envp)
 #endif
     }
 
+    colo_info_init();
+
     if (net_init_clients() < 0) {
         exit(1);
     }
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 04/34] migration: Integrate COLO checkpoint process into migration

[zhanghailiang]

Add a migrate state: MIGRATION_STATUS_COLO, enter this migration state
after the first live migration successfully finished.

We reuse migration thread, so if colo is enabled by user, migration thread will
go into the process of colo.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v11:
- Rebase to master
- Add Reviewed-by tag
v10:
- Simplify process by dropping colo thread and reusing migration thread.
     (Dave's suggestion)
---
 include/migration/colo.h |  3 +++
 migration/colo.c         | 31 +++++++++++++++++++++++++++++++
 migration/migration.c    | 30 ++++++++++++++++++++++++++----
 migration/trace-events   |  3 +++
 qapi-schema.json         |  4 +++-
 stubs/migration-colo.c   |  9 +++++++++
 6 files changed, 75 insertions(+), 5 deletions(-)

diff --git a/include/migration/colo.h b/include/migration/colo.h
index 1c899a0..bf84b99 100644
--- a/include/migration/colo.h
+++ b/include/migration/colo.h
@@ -19,4 +19,7 @@
 bool colo_supported(void);
 void colo_info_init(void);
 
+void migrate_start_colo_process(MigrationState *s);
+bool migration_in_colo_state(void);
+
 #endif
diff --git a/migration/colo.c b/migration/colo.c
index 5749016..d2c2d1f 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -11,9 +11,40 @@
  */
 
 #include "qemu/osdep.h"
+#include "sysemu/sysemu.h"
 #include "migration/colo.h"
+#include "trace.h"
 
 bool colo_supported(void)
 {
     return true;
 }
+
+bool migration_in_colo_state(void)
+{
+    MigrationState *s = migrate_get_current();
+
+    return (s->state == MIGRATION_STATUS_COLO);
+}
+
+static void colo_process_checkpoint(MigrationState *s)
+{
+    qemu_mutex_lock_iothread();
+    vm_start();
+    qemu_mutex_unlock_iothread();
+    trace_colo_vm_state_change("stop", "run");
+
+    /*TODO: COLO checkpoint savevm loop*/
+
+    migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
+                      MIGRATION_STATUS_COMPLETED);
+}
+
+void migrate_start_colo_process(MigrationState *s)
+{
+    qemu_mutex_unlock_iothread();
+    migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
+                      MIGRATION_STATUS_COLO);
+    colo_process_checkpoint(s);
+    qemu_mutex_lock_iothread();
+}
diff --git a/migration/migration.c b/migration/migration.c
index 17f0f75..fce0ba4 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -690,6 +690,10 @@ MigrationInfo *qmp_query_migrate(Error **errp)
 
         get_xbzrle_cache_stats(info);
         break;
+    case MIGRATION_STATUS_COLO:
+        info->has_status = true;
+        /* TODO: display COLO specific information (checkpoint info etc.) */
+        break;
     case MIGRATION_STATUS_COMPLETED:
         get_xbzrle_cache_stats(info);
 
@@ -1094,7 +1098,8 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
     params.shared = has_inc && inc;
 
     if (migration_is_setup_or_active(s->state) ||
-        s->state == MIGRATION_STATUS_CANCELLING) {
+        s->state == MIGRATION_STATUS_CANCELLING ||
+        s->state == MIGRATION_STATUS_COLO) {
         error_setg(errp, QERR_MIGRATION_ACTIVE);
         return;
     }
@@ -1686,8 +1691,11 @@ static void migration_completion(MigrationState *s, int current_active_state,
         goto fail_invalidate;
     }
 
-    migrate_set_state(&s->state, current_active_state,
-                      MIGRATION_STATUS_COMPLETED);
+    if (!migrate_colo_enabled()) {
+        migrate_set_state(&s->state, current_active_state,
+                          MIGRATION_STATUS_COMPLETED);
+    }
+
     return;
 
 fail_invalidate:
@@ -1732,6 +1740,7 @@ static void *migration_thread(void *opaque)
     bool entered_postcopy = false;
     /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */
     enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE;
+    bool enable_colo = migrate_colo_enabled();
 
     rcu_register_thread();
 
@@ -1840,7 +1849,11 @@ static void *migration_thread(void *opaque)
     end_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 
     qemu_mutex_lock_iothread();
-    qemu_savevm_state_cleanup();
+    /* The resource has been allocated by migration will be reused in COLO
+      process, so don't release them. */
+    if (!enable_colo) {
+        qemu_savevm_state_cleanup();
+    }
     if (s->state == MIGRATION_STATUS_COMPLETED) {
         uint64_t transferred_bytes = qemu_ftell(s->to_dst_file);
         s->total_time = end_time - s->total_time;
@@ -1853,6 +1866,15 @@ static void *migration_thread(void *opaque)
         }
         runstate_set(RUN_STATE_POSTMIGRATE);
     } else {
+        if (s->state == MIGRATION_STATUS_ACTIVE && enable_colo) {
+            migrate_start_colo_process(s);
+            qemu_savevm_state_cleanup();
+            /*
+            * Fixme: we will run VM in COLO no matter its old running state.
+            * After exited COLO, we will keep running.
+            */
+            old_vm_running = true;
+        }
         if (old_vm_running && !entered_postcopy) {
             vm_start();
         } else {
diff --git a/migration/trace-events b/migration/trace-events
index 8568dab..cccb87f 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -207,3 +207,6 @@ migration_tls_outgoing_handshake_complete(void) ""
 migration_tls_incoming_handshake_start(void) ""
 migration_tls_incoming_handshake_error(const char *err) "err=%s"
 migration_tls_incoming_handshake_complete(void) ""
+
+# migration/colo.c
+colo_vm_state_change(const char *old, const char *new) "Change '%s' => '%s'"
diff --git a/qapi-schema.json b/qapi-schema.json
index cdab6cf..cb69db5 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -438,12 +438,14 @@
 #
 # @failed: some error occurred during migration process.
 #
+# @colo: VM is in the process of fault tolerance. (since 2.8)
+#
 # Since: 2.3
 #
 ##
 { 'enum': 'MigrationStatus',
   'data': [ 'none', 'setup', 'cancelling', 'cancelled',
-            'active', 'postcopy-active', 'completed', 'failed' ] }
+            'active', 'postcopy-active', 'completed', 'failed', 'colo' ] }
 
 ##
 # @MigrationInfo
diff --git a/stubs/migration-colo.c b/stubs/migration-colo.c
index d215057..0c8eef4 100644
--- a/stubs/migration-colo.c
+++ b/stubs/migration-colo.c
@@ -17,3 +17,12 @@ bool colo_supported(void)
 {
     return false;
 }
+
+bool migration_in_colo_state(void)
+{
+    return false;
+}
+
+void migrate_start_colo_process(MigrationState *s)
+{
+}
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 05/34] migration: Integrate COLO checkpoint process into loadvm

[zhanghailiang]

Switch from normal migration loadvm process into COLO checkpoint process if
COLO mode is enabled.
We add three new members to struct MigrationIncomingState, 'have_colo_incoming_thread'
and 'colo_incoming_thread' record the colo related threads for secondary VM,
'migration_incoming_co' records the original migration incoming coroutine.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v12:
- Add Reviewed-by tag
v11:
- We moved the place of bdrv_invalidate_cache_all(), but done the deleting work
  in other patch. Fix it.
- Add documentation for colo in 'MigrationStatus' (Eric's review comment)
v10:
- fix a bug about fd leak which is found by Dave.
---
 include/migration/colo.h      |  7 +++++++
 include/migration/migration.h |  7 +++++++
 migration/colo-comm.c         | 10 ++++++++++
 migration/colo.c              | 21 +++++++++++++++++++++
 migration/migration.c         | 12 ++++++++++++
 stubs/migration-colo.c        | 10 ++++++++++
 6 files changed, 67 insertions(+)

diff --git a/include/migration/colo.h b/include/migration/colo.h
index bf84b99..b40676c 100644
--- a/include/migration/colo.h
+++ b/include/migration/colo.h
@@ -15,6 +15,8 @@
 
 #include "qemu-common.h"
 #include "migration/migration.h"
+#include "qemu/coroutine_int.h"
+#include "qemu/thread.h"
 
 bool colo_supported(void);
 void colo_info_init(void);
@@ -22,4 +24,9 @@ void colo_info_init(void);
 void migrate_start_colo_process(MigrationState *s);
 bool migration_in_colo_state(void);
 
+/* loadvm */
+bool migration_incoming_enable_colo(void);
+void migration_incoming_exit_colo(void);
+void *colo_process_incoming_thread(void *opaque);
+bool migration_incoming_in_colo_state(void);
 #endif
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 5effc05..f4b215a 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -21,6 +21,7 @@
 #include "migration/vmstate.h"
 #include "qapi-types.h"
 #include "exec/cpu-common.h"
+#include "qemu/coroutine_int.h"
 
 #define QEMU_VM_FILE_MAGIC           0x5145564d
 #define QEMU_VM_FILE_VERSION_COMPAT  0x00000002
@@ -107,6 +108,12 @@ struct MigrationIncomingState {
     QEMUBH *bh;
 
     int state;
+
+    bool have_colo_incoming_thread;
+    QemuThread colo_incoming_thread;
+    /* The coroutine we should enter (back) after failover */
+    Coroutine *migration_incoming_co;
+
     /* See savevm.c */
     LoadStateEntry_Head loadvm_handlers;
 };
diff --git a/migration/colo-comm.c b/migration/colo-comm.c
index 2d06ace..1a36893 100644
--- a/migration/colo-comm.c
+++ b/migration/colo-comm.c
@@ -49,3 +49,13 @@ void colo_info_init(void)
 {
     vmstate_register(NULL, 0, &colo_state, &colo_info);
 }
+
+bool migration_incoming_enable_colo(void)
+{
+    return colo_info.colo_requested;
+}
+
+void migration_incoming_exit_colo(void)
+{
+    colo_info.colo_requested = 0;
+}
diff --git a/migration/colo.c b/migration/colo.c
index d2c2d1f..68815c0 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -27,6 +27,13 @@ bool migration_in_colo_state(void)
     return (s->state == MIGRATION_STATUS_COLO);
 }
 
+bool migration_incoming_in_colo_state(void)
+{
+    MigrationIncomingState *mis = migration_incoming_get_current();
+
+    return mis && (mis->state == MIGRATION_STATUS_COLO);
+}
+
 static void colo_process_checkpoint(MigrationState *s)
 {
     qemu_mutex_lock_iothread();
@@ -48,3 +55,17 @@ void migrate_start_colo_process(MigrationState *s)
     colo_process_checkpoint(s);
     qemu_mutex_lock_iothread();
 }
+
+void *colo_process_incoming_thread(void *opaque)
+{
+    MigrationIncomingState *mis = opaque;
+
+    migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
+                      MIGRATION_STATUS_COLO);
+
+    /* TODO: COLO checkpoint restore loop */
+
+    migration_incoming_exit_colo();
+
+    return NULL;
+}
diff --git a/migration/migration.c b/migration/migration.c
index fce0ba4..e5f47d0 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -402,6 +402,18 @@ static void process_incoming_migration_co(void *opaque)
         /* Else if something went wrong then just fall out of the normal exit */
     }
 
+    /* we get colo info, and know if we are in colo mode */
+    if (!ret && migration_incoming_enable_colo()) {
+        mis->migration_incoming_co = qemu_coroutine_self();
+        qemu_thread_create(&mis->colo_incoming_thread, "colo incoming",
+             colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE);
+        mis->have_colo_incoming_thread = true;
+        qemu_coroutine_yield();
+
+        /* Wait checkpoint incoming thread exit before free resource */
+        qemu_thread_join(&mis->colo_incoming_thread);
+    }
+
     qemu_fclose(f);
     free_xbzrle_decoded_buf();
 
diff --git a/stubs/migration-colo.c b/stubs/migration-colo.c
index 0c8eef4..7b72395 100644
--- a/stubs/migration-colo.c
+++ b/stubs/migration-colo.c
@@ -23,6 +23,16 @@ bool migration_in_colo_state(void)
     return false;
 }
 
+bool migration_incoming_in_colo_state(void)
+{
+    return false;
+}
+
 void migrate_start_colo_process(MigrationState *s)
 {
 }
+
+void *colo_process_incoming_thread(void *opaque)
+{
+    return NULL;
+}
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 06/34] COLO/migration: Create a new communication path from destination to source

[zhanghailiang]

This new communication path will be used for returning messages
from destination to source.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v13:
- Remove useless error report
v12:
- Add Reviewed-by tag
v11:
- Rebase master to use qemu_file_get_return_path() for opening return path
v10:
- fix the the error log (Dave's suggestion).
---
 migration/colo.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/migration/colo.c b/migration/colo.c
index 68815c0..13204fc 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -14,6 +14,7 @@
 #include "sysemu/sysemu.h"
 #include "migration/colo.h"
 #include "trace.h"
+#include "qemu/error-report.h"
 
 bool colo_supported(void)
 {
@@ -36,6 +37,12 @@ bool migration_incoming_in_colo_state(void)
 
 static void colo_process_checkpoint(MigrationState *s)
 {
+    s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file);
+    if (!s->rp_state.from_dst_file) {
+        error_report("Open QEMUFile from_dst_file failed");
+        goto out;
+    }
+
     qemu_mutex_lock_iothread();
     vm_start();
     qemu_mutex_unlock_iothread();
@@ -43,8 +50,13 @@ static void colo_process_checkpoint(MigrationState *s)
 
     /*TODO: COLO checkpoint savevm loop*/
 
+out:
     migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
                       MIGRATION_STATUS_COMPLETED);
+
+    if (s->rp_state.from_dst_file) {
+        qemu_fclose(s->rp_state.from_dst_file);
+    }
 }
 
 void migrate_start_colo_process(MigrationState *s)
@@ -63,8 +75,24 @@ void *colo_process_incoming_thread(void *opaque)
     migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
                       MIGRATION_STATUS_COLO);
 
+    mis->to_src_file = qemu_file_get_return_path(mis->from_src_file);
+    if (!mis->to_src_file) {
+        error_report("colo incoming thread: Open QEMUFile to_src_file failed");
+        goto out;
+    }
+    /*
+     * Note: We set the fd to unblocked in migration incoming coroutine,
+     * But here we are in the colo incoming thread, so it is ok to set the
+     * fd back to blocked.
+     */
+    qemu_file_set_blocking(mis->from_src_file, true);
+
     /* TODO: COLO checkpoint restore loop */
 
+out:
+    if (mis->to_src_file) {
+        qemu_fclose(mis->to_src_file);
+    }
     migration_incoming_exit_colo();
 
     return NULL;
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 07/34] COLO: Implement COLO checkpoint protocol

[zhanghailiang]

We need communications protocol of user-defined to control the checkpoint
process.

The new checkpoint request is started by Primary VM, and the interactive process
like below:
Checkpoint synchronizing points:

                   Primary               Secondary
                                            initial work
'checkpoint-ready'    <-------------------- @

'checkpoint-request'  @ -------------------->
                                            Suspend (Only in hybrid mode)
'checkpoint-reply'    <-------------------- @
                      Suspend&Save state
'vmstate-send'        @ -------------------->
                      Send state            Receive state
'vmstate-received'    <-------------------- @
                      Release packets       Load state
'vmstate-load'        <-------------------- @
                      Resume                Resume (Only in hybrid mode)

                      Start Comparing (Only in hybrid mode)
NOTE:
 1) '@' who sends the message
 2) Every sync-point is synchronized by two sides with only
    one handshake(single direction) for low-latency.
    If more strict synchronization is required, a opposite direction
    sync-point should be added.
 3) Since sync-points are single direction, the remote side may
    go forward a lot when this side just receives the sync-point.
 4) For now, we only support 'periodic' checkpoint, for which
   the Secondary VM is not running, later we will support 'hybrid' mode.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v16:
- Rename 'colo_put/get[_check]_cmd()' to 'colo_send/receive[_check]_message()'
v14:
- Rename 'COLOCommand' to 'COLOMessage'. (Markus's suggestion)
- Add Reviewd-by tag
v13:
- Refactor colo command related helper functions, use 'Error **errp' parameter
  instead of return value to indicate success or failure.
- Fix some other comments from Markus.

v12:
- Rename colo_ctl_put() to colo_put_cmd()
- Rename colo_ctl_get() to colo_get_check_cmd() and drop
  the third parameter
- Rename colo_ctl_get_cmd() to colo_get_cmd()
- Remove useless 'invalid' member for COLOcommand enum.
v11:
- Add missing 'checkpoint-ready' communication in comment.
- Use parameter to return 'value' for colo_ctl_get() (Dave's suggestion)
- Fix trace for colo_ctl_get() to trace command and value both
v10:
- Rename enum COLOCmd to COLOCommand (Eric's suggestion).
- Remove unused 'ram-steal'
---
 migration/colo.c       | 200 ++++++++++++++++++++++++++++++++++++++++++++++++-
 migration/trace-events |   2 +
 qapi-schema.json       |  25 +++++++
 3 files changed, 225 insertions(+), 2 deletions(-)

diff --git a/migration/colo.c b/migration/colo.c
index 13204fc..1cf0159 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -15,6 +15,7 @@
 #include "migration/colo.h"
 #include "trace.h"
 #include "qemu/error-report.h"
+#include "qapi/error.h"
 
 bool colo_supported(void)
 {
@@ -35,22 +36,146 @@ bool migration_incoming_in_colo_state(void)
     return mis && (mis->state == MIGRATION_STATUS_COLO);
 }
 
+static void colo_send_message(QEMUFile *f, COLOMessage msg,
+                              Error **errp)
+{
+    int ret;
+
+    if (msg >= COLO_MESSAGE__MAX) {
+        error_setg(errp, "%s: Invalid message", __func__);
+        return;
+    }
+    qemu_put_be32(f, msg);
+    qemu_fflush(f);
+
+    ret = qemu_file_get_error(f);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Can't send COLO message");
+    }
+    trace_colo_send_message(COLOMessage_lookup[msg]);
+}
+
+static COLOMessage colo_receive_message(QEMUFile *f, Error **errp)
+{
+    COLOMessage msg;
+    int ret;
+
+    msg = qemu_get_be32(f);
+    ret = qemu_file_get_error(f);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Can't receive COLO message");
+        return msg;
+    }
+    if (msg >= COLO_MESSAGE__MAX) {
+        error_setg(errp, "%s: Invalid message", __func__);
+        return msg;
+    }
+    trace_colo_receive_message(COLOMessage_lookup[msg]);
+    return msg;
+}
+
+static void colo_receive_check_message(QEMUFile *f, COLOMessage expect_msg,
+                                       Error **errp)
+{
+    COLOMessage msg;
+    Error *local_err = NULL;
+
+    msg = colo_receive_message(f, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+    if (msg != expect_msg) {
+        error_setg(errp, "Unexpected COLO message %d, expected %d",
+                          msg, expect_msg);
+    }
+}
+
+static int colo_do_checkpoint_transaction(MigrationState *s)
+{
+    Error *local_err = NULL;
+
+    colo_send_message(s->to_dst_file, COLO_MESSAGE_CHECKPOINT_REQUEST,
+                      &local_err);
+    if (local_err) {
+        goto out;
+    }
+
+    colo_receive_check_message(s->rp_state.from_dst_file,
+                    COLO_MESSAGE_CHECKPOINT_REPLY, &local_err);
+    if (local_err) {
+        goto out;
+    }
+
+    /* TODO: suspend and save vm state to colo buffer */
+
+    colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err);
+    if (local_err) {
+        goto out;
+    }
+
+    /* TODO: send vmstate to Secondary */
+
+    colo_receive_check_message(s->rp_state.from_dst_file,
+                       COLO_MESSAGE_VMSTATE_RECEIVED, &local_err);
+    if (local_err) {
+        goto out;
+    }
+
+    colo_receive_check_message(s->rp_state.from_dst_file,
+                       COLO_MESSAGE_VMSTATE_LOADED, &local_err);
+    if (local_err) {
+        goto out;
+    }
+
+    /* TODO: resume Primary */
+
+    return 0;
+out:
+    if (local_err) {
+        error_report_err(local_err);
+    }
+    return -EINVAL;
+}
+
 static void colo_process_checkpoint(MigrationState *s)
 {
+    Error *local_err = NULL;
+    int ret;
+
     s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file);
     if (!s->rp_state.from_dst_file) {
         error_report("Open QEMUFile from_dst_file failed");
         goto out;
     }
 
+    /*
+     * Wait for Secondary finish loading VM states and enter COLO
+     * restore.
+     */
+    colo_receive_check_message(s->rp_state.from_dst_file,
+                       COLO_MESSAGE_CHECKPOINT_READY, &local_err);
+    if (local_err) {
+        goto out;
+    }
+
     qemu_mutex_lock_iothread();
     vm_start();
     qemu_mutex_unlock_iothread();
     trace_colo_vm_state_change("stop", "run");
 
-    /*TODO: COLO checkpoint savevm loop*/
+    while (s->state == MIGRATION_STATUS_COLO) {
+        ret = colo_do_checkpoint_transaction(s);
+        if (ret < 0) {
+            goto out;
+        }
+    }
 
 out:
+    /* Throw the unreported error message after exited from loop */
+    if (local_err) {
+        error_report_err(local_err);
+    }
     migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
                       MIGRATION_STATUS_COMPLETED);
 
@@ -68,9 +193,33 @@ void migrate_start_colo_process(MigrationState *s)
     qemu_mutex_lock_iothread();
 }
 
+static void colo_wait_handle_message(QEMUFile *f, int *checkpoint_request,
+                                     Error **errp)
+{
+    COLOMessage msg;
+    Error *local_err = NULL;
+
+    msg = colo_receive_message(f, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    switch (msg) {
+    case COLO_MESSAGE_CHECKPOINT_REQUEST:
+        *checkpoint_request = 1;
+        break;
+    default:
+        *checkpoint_request = 0;
+        error_setg(errp, "Got unknown COLO message: %d", msg);
+        break;
+    }
+}
+
 void *colo_process_incoming_thread(void *opaque)
 {
     MigrationIncomingState *mis = opaque;
+    Error *local_err = NULL;
 
     migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
                       MIGRATION_STATUS_COLO);
@@ -87,9 +236,56 @@ void *colo_process_incoming_thread(void *opaque)
      */
     qemu_file_set_blocking(mis->from_src_file, true);
 
-    /* TODO: COLO checkpoint restore loop */
+    colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
+                      &local_err);
+    if (local_err) {
+        goto out;
+    }
+
+    while (mis->state == MIGRATION_STATUS_COLO) {
+        int request;
+
+        colo_wait_handle_message(mis->from_src_file, &request, &local_err);
+        if (local_err) {
+            goto out;
+        }
+        assert(request);
+        /* FIXME: This is unnecessary for periodic checkpoint mode */
+        colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_REPLY,
+                     &local_err);
+        if (local_err) {
+            goto out;
+        }
+
+        colo_receive_check_message(mis->from_src_file,
+                           COLO_MESSAGE_VMSTATE_SEND, &local_err);
+        if (local_err) {
+            goto out;
+        }
+
+        /* TODO: read migration data into colo buffer */
+
+        colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_RECEIVED,
+                     &local_err);
+        if (local_err) {
+            goto out;
+        }
+
+        /* TODO: load vm state */
+
+        colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED,
+                     &local_err);
+        if (local_err) {
+            goto out;
+        }
+    }
 
 out:
+    /* Throw the unreported error message after exited from loop */
+    if (local_err) {
+        error_report_err(local_err);
+    }
+
     if (mis->to_src_file) {
         qemu_fclose(mis->to_src_file);
     }
diff --git a/migration/trace-events b/migration/trace-events
index cccb87f..e98eaef 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -210,3 +210,5 @@ migration_tls_incoming_handshake_complete(void) ""
 
 # migration/colo.c
 colo_vm_state_change(const char *old, const char *new) "Change '%s' => '%s'"
+colo_send_message(const char *msg) "Send '%s' message"
+colo_receive_message(const char *msg) "Receive '%s' message"
diff --git a/qapi-schema.json b/qapi-schema.json
index cb69db5..f2657a4 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -779,6 +779,31 @@
 { 'command': 'migrate-start-postcopy' }
 
 ##
+# @COLOMessage
+#
+# The message transmission between PVM and SVM
+#
+# @checkpoint-ready: SVM is ready for checkpointing
+#
+# @checkpoint-request: PVM tells SVM to prepare for new checkpointing
+#
+# @checkpoint-reply: SVM gets PVM's checkpoint request
+#
+# @vmstate-send: VM's state will be sent by PVM.
+#
+# @vmstate-size: The total size of VMstate.
+#
+# @vmstate-received: VM's state has been received by SVM.
+#
+# @vmstate-loaded: VM's state has been loaded by SVM.
+#
+# Since: 2.8
+##
+{ 'enum': 'COLOMessage',
+  'data': [ 'checkpoint-ready', 'checkpoint-request', 'checkpoint-reply',
+            'vmstate-send', 'vmstate-size', 'vmstate-received',
+            'vmstate-loaded' ] }
+
 # @MouseInfo:
 #
 # Information about a mouse device.
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 08/34] COLO: Add a new RunState RUN_STATE_COLO

[zhanghailiang]

Guest will enter this state when paused to save/restore VM state
under colo checkpoint.

Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 qapi-schema.json | 5 ++++-
 vl.c             | 8 ++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/qapi-schema.json b/qapi-schema.json
index f2657a4..0ff1a63 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -154,12 +154,15 @@
 # @watchdog: the watchdog action is configured to pause and has been triggered
 #
 # @guest-panicked: guest has been panicked as a result of guest OS panic
+#
+# @colo: guest is paused to save/restore VM state under colo checkpoint (since
+# 2.8)
 ##
 { 'enum': 'RunState',
   'data': [ 'debug', 'inmigrate', 'internal-error', 'io-error', 'paused',
             'postmigrate', 'prelaunch', 'finish-migrate', 'restore-vm',
             'running', 'save-vm', 'shutdown', 'suspended', 'watchdog',
-            'guest-panicked' ] }
+            'guest-panicked', 'colo' ] }
 
 ##
 # @StatusInfo:
diff --git a/vl.c b/vl.c
index 097295d..62e8d41 100644
--- a/vl.c
+++ b/vl.c
@@ -574,6 +574,7 @@ static const RunStateTransition runstate_transitions_def[] = {
     { RUN_STATE_INMIGRATE, RUN_STATE_FINISH_MIGRATE },
     { RUN_STATE_INMIGRATE, RUN_STATE_PRELAUNCH },
     { RUN_STATE_INMIGRATE, RUN_STATE_POSTMIGRATE },
+    { RUN_STATE_INMIGRATE, RUN_STATE_COLO },
 
     { RUN_STATE_INTERNAL_ERROR, RUN_STATE_PAUSED },
     { RUN_STATE_INTERNAL_ERROR, RUN_STATE_FINISH_MIGRATE },
@@ -586,6 +587,7 @@ static const RunStateTransition runstate_transitions_def[] = {
     { RUN_STATE_PAUSED, RUN_STATE_RUNNING },
     { RUN_STATE_PAUSED, RUN_STATE_FINISH_MIGRATE },
     { RUN_STATE_PAUSED, RUN_STATE_PRELAUNCH },
+    { RUN_STATE_PAUSED, RUN_STATE_COLO},
 
     { RUN_STATE_POSTMIGRATE, RUN_STATE_RUNNING },
     { RUN_STATE_POSTMIGRATE, RUN_STATE_FINISH_MIGRATE },
@@ -598,10 +600,13 @@ static const RunStateTransition runstate_transitions_def[] = {
     { RUN_STATE_FINISH_MIGRATE, RUN_STATE_RUNNING },
     { RUN_STATE_FINISH_MIGRATE, RUN_STATE_POSTMIGRATE },
     { RUN_STATE_FINISH_MIGRATE, RUN_STATE_PRELAUNCH },
+    { RUN_STATE_FINISH_MIGRATE, RUN_STATE_COLO},
 
     { RUN_STATE_RESTORE_VM, RUN_STATE_RUNNING },
     { RUN_STATE_RESTORE_VM, RUN_STATE_PRELAUNCH },
 
+    { RUN_STATE_COLO, RUN_STATE_RUNNING },
+
     { RUN_STATE_RUNNING, RUN_STATE_DEBUG },
     { RUN_STATE_RUNNING, RUN_STATE_INTERNAL_ERROR },
     { RUN_STATE_RUNNING, RUN_STATE_IO_ERROR },
@@ -612,6 +617,7 @@ static const RunStateTransition runstate_transitions_def[] = {
     { RUN_STATE_RUNNING, RUN_STATE_SHUTDOWN },
     { RUN_STATE_RUNNING, RUN_STATE_WATCHDOG },
     { RUN_STATE_RUNNING, RUN_STATE_GUEST_PANICKED },
+    { RUN_STATE_RUNNING, RUN_STATE_COLO},
 
     { RUN_STATE_SAVE_VM, RUN_STATE_RUNNING },
 
@@ -624,10 +630,12 @@ static const RunStateTransition runstate_transitions_def[] = {
     { RUN_STATE_SUSPENDED, RUN_STATE_RUNNING },
     { RUN_STATE_SUSPENDED, RUN_STATE_FINISH_MIGRATE },
     { RUN_STATE_SUSPENDED, RUN_STATE_PRELAUNCH },
+    { RUN_STATE_SUSPENDED, RUN_STATE_COLO},
 
     { RUN_STATE_WATCHDOG, RUN_STATE_RUNNING },
     { RUN_STATE_WATCHDOG, RUN_STATE_FINISH_MIGRATE },
     { RUN_STATE_WATCHDOG, RUN_STATE_PRELAUNCH },
+    { RUN_STATE_WATCHDOG, RUN_STATE_COLO},
 
     { RUN_STATE_GUEST_PANICKED, RUN_STATE_RUNNING },
     { RUN_STATE_GUEST_PANICKED, RUN_STATE_FINISH_MIGRATE },
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 09/34] COLO: Save PVM state to secondary side when do checkpoint

[zhanghailiang]

The main process of the checkpoint is to synchronize SVM with PVM.
VM's state includes ram and device state. So we will migrate PVM's
state to SVM when do checkpoint, just like migration does.

We will cache PVM's state in slave, we use QEMUSizedBuffer
to store the data, we need to know the size of VM state, so in master,
we use qsb to store VM state temporarily, get the data size by call qsb_get_length()
and then migrate the data to the qsb in the secondary side.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v17:
- Rebase to master, use the new channel-buffer API
v16:
- Rename colo_put_cmd_value() to colo_send_message_value()
v13:
- Refactor colo_put_cmd_value() to use 'Error **errp' to indicate success
  or failure.
v12:
- Replace the old colo_ctl_get() with the new helper function colo_put_cmd_value()
v11:
- Add Reviewed-by tag
---
 migration/colo.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++------
 migration/ram.c  | 39 +++++++++++++++++++-------
 2 files changed, 104 insertions(+), 18 deletions(-)

diff --git a/migration/colo.c b/migration/colo.c
index 1cf0159..ec43250 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -13,10 +13,13 @@
 #include "qemu/osdep.h"
 #include "sysemu/sysemu.h"
 #include "migration/colo.h"
+#include "io/channel-buffer.h"
 #include "trace.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
 
+#define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024)
+
 bool colo_supported(void)
 {
     return true;
@@ -55,6 +58,27 @@ static void colo_send_message(QEMUFile *f, COLOMessage msg,
     trace_colo_send_message(COLOMessage_lookup[msg]);
 }
 
+static void colo_send_message_value(QEMUFile *f, COLOMessage msg,
+                                    uint64_t value, Error **errp)
+{
+    Error *local_err = NULL;
+    int ret;
+
+    colo_send_message(f, msg, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+    qemu_put_be64(f, value);
+    qemu_fflush(f);
+
+    ret = qemu_file_get_error(f);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Failed to send value for message:%s",
+                         COLOMessage_lookup[msg]);
+    }
+}
+
 static COLOMessage colo_receive_message(QEMUFile *f, Error **errp)
 {
     COLOMessage msg;
@@ -91,9 +115,12 @@ static void colo_receive_check_message(QEMUFile *f, COLOMessage expect_msg,
     }
 }
 
-static int colo_do_checkpoint_transaction(MigrationState *s)
+static int colo_do_checkpoint_transaction(MigrationState *s,
+                                          QIOChannelBuffer *bioc,
+                                          QEMUFile *fb)
 {
     Error *local_err = NULL;
+    int ret = -1;
 
     colo_send_message(s->to_dst_file, COLO_MESSAGE_CHECKPOINT_REQUEST,
                       &local_err);
@@ -106,15 +133,46 @@ static int colo_do_checkpoint_transaction(MigrationState *s)
     if (local_err) {
         goto out;
     }
+    /* Reset channel-buffer directly */
+    qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL);
+    bioc->usage = 0;
+
+    qemu_mutex_lock_iothread();
+    vm_stop_force_state(RUN_STATE_COLO);
+    qemu_mutex_unlock_iothread();
+    trace_colo_vm_state_change("run", "stop");
 
-    /* TODO: suspend and save vm state to colo buffer */
+    /* Disable block migration */
+    s->params.blk = 0;
+    s->params.shared = 0;
+    qemu_savevm_state_header(fb);
+    qemu_savevm_state_begin(fb, &s->params);
+    qemu_mutex_lock_iothread();
+    qemu_savevm_state_complete_precopy(fb, false);
+    qemu_mutex_unlock_iothread();
+
+    qemu_fflush(fb);
 
     colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err);
     if (local_err) {
         goto out;
     }
+    /*
+     * We need the size of the VMstate data in Secondary side,
+     * With which we can decide how much data should be read.
+     */
+    colo_send_message_value(s->to_dst_file, COLO_MESSAGE_VMSTATE_SIZE,
+                            bioc->usage, &local_err);
+    if (local_err) {
+        goto out;
+    }
 
-    /* TODO: send vmstate to Secondary */
+    qemu_put_buffer(s->to_dst_file, bioc->data, bioc->usage);
+    qemu_fflush(s->to_dst_file);
+    ret = qemu_file_get_error(s->to_dst_file);
+    if (ret < 0) {
+        goto out;
+    }
 
     colo_receive_check_message(s->rp_state.from_dst_file,
                        COLO_MESSAGE_VMSTATE_RECEIVED, &local_err);
@@ -128,18 +186,24 @@ static int colo_do_checkpoint_transaction(MigrationState *s)
         goto out;
     }
 
-    /* TODO: resume Primary */
+    ret = 0;
+
+    qemu_mutex_lock_iothread();
+    vm_start();
+    qemu_mutex_unlock_iothread();
+    trace_colo_vm_state_change("stop", "run");
 
-    return 0;
 out:
     if (local_err) {
         error_report_err(local_err);
     }
-    return -EINVAL;
+    return ret;
 }
 
 static void colo_process_checkpoint(MigrationState *s)
 {
+    QIOChannelBuffer *bioc;
+    QEMUFile *fb = NULL;
     Error *local_err = NULL;
     int ret;
 
@@ -158,6 +222,9 @@ static void colo_process_checkpoint(MigrationState *s)
     if (local_err) {
         goto out;
     }
+    bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE);
+    fb = qemu_fopen_channel_output(QIO_CHANNEL(bioc));
+    object_unref(OBJECT(bioc));
 
     qemu_mutex_lock_iothread();
     vm_start();
@@ -165,7 +232,7 @@ static void colo_process_checkpoint(MigrationState *s)
     trace_colo_vm_state_change("stop", "run");
 
     while (s->state == MIGRATION_STATUS_COLO) {
-        ret = colo_do_checkpoint_transaction(s);
+        ret = colo_do_checkpoint_transaction(s, bioc, fb);
         if (ret < 0) {
             goto out;
         }
@@ -178,7 +245,7 @@ out:
     }
     migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
                       MIGRATION_STATUS_COMPLETED);
-
+    qemu_fclose(fb);
     if (s->rp_state.from_dst_file) {
         qemu_fclose(s->rp_state.from_dst_file);
     }
diff --git a/migration/ram.c b/migration/ram.c
index 815bc0e..e9067c5 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -43,6 +43,7 @@
 #include "trace.h"
 #include "exec/ram_addr.h"
 #include "qemu/rcu_queue.h"
+#include "migration/colo.h"
 
 #ifdef DEBUG_MIGRATION_RAM
 #define DPRINTF(fmt, ...) \
@@ -1868,16 +1869,8 @@ err:
     return ret;
 }
 
-
-/* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
- * long-running RCU critical section.  When rcu-reclaims in the code
- * start to become numerous it will be necessary to reduce the
- * granularity of these critical sections.
- */
-
-static int ram_save_setup(QEMUFile *f, void *opaque)
+static int ram_save_init_globals(void)
 {
-    RAMBlock *block;
     int64_t ram_bitmap_pages; /* Size of bitmap in pages, including gaps */
 
     dirty_rate_high_cnt = 0;
@@ -1943,6 +1936,31 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
     migration_bitmap_sync();
     qemu_mutex_unlock_ramlist();
     qemu_mutex_unlock_iothread();
+    rcu_read_unlock();
+
+    return 0;
+}
+
+/* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
+ * long-running RCU critical section.  When rcu-reclaims in the code
+ * start to become numerous it will be necessary to reduce the
+ * granularity of these critical sections.
+ */
+
+static int ram_save_setup(QEMUFile *f, void *opaque)
+{
+    RAMBlock *block;
+
+    /*
+     * migration has already setup the bitmap, reuse it.
+     */
+    if (!migration_in_colo_state()) {
+        if (ram_save_init_globals() < 0) {
+            return -1;
+         }
+    }
+
+    rcu_read_lock();
 
     qemu_put_be64(f, ram_bytes_total() | RAM_SAVE_FLAG_MEM_SIZE);
 
@@ -2044,7 +2062,8 @@ static int ram_save_complete(QEMUFile *f, void *opaque)
     while (true) {
         int pages;
 
-        pages = ram_find_and_save_block(f, true, &bytes_transferred);
+        pages = ram_find_and_save_block(f, !migration_in_colo_state(),
+                                        &bytes_transferred);
         /* no more blocks to sent */
         if (pages == 0) {
             break;
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 10/34] COLO: Load PVM's dirty pages into SVM's RAM cache temporarily

[zhanghailiang]

We should not load PVM's state directly into SVM, because there maybe some
errors happen when SVM is receving data, which will break SVM.

We need to ensure receving all data before load the state into SVM. We use
an extra memory to cache these data (PVM's ram). The ram cache in secondary side
is initially the same as SVM/PVM's memory. And in the process of checkpoint,
we cache the dirty pages of PVM into this ram cache firstly, so this ram cache
always the same as PVM's memory at every checkpoint, then we flush this cached ram
to SVM after we receive all PVM's state.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v12:
- Fix minor error in error_report (Dave's comment)
- Add Reviewed-by tag
v11:
- Rename 'host_cache' to 'colo_cache' (Dave's suggestion)
v10:
- Split the process of dirty pages recording into a new patch
---
 include/exec/ram_addr.h       |  1 +
 include/migration/migration.h |  4 +++
 migration/colo.c              | 11 +++++++
 migration/ram.c               | 73 ++++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 88 insertions(+), 1 deletion(-)

diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 2a9465d..b4c04fb 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -26,6 +26,7 @@ struct RAMBlock {
     struct rcu_head rcu;
     struct MemoryRegion *mr;
     uint8_t *host;
+    uint8_t *colo_cache; /* For colo, VM's ram cache */
     ram_addr_t offset;
     ram_addr_t used_length;
     ram_addr_t max_length;
diff --git a/include/migration/migration.h b/include/migration/migration.h
index f4b215a..55679b5 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -362,4 +362,8 @@ int ram_save_queue_pages(MigrationState *ms, const char *rbname,
 PostcopyState postcopy_state_get(void);
 /* Set the state and return the old state */
 PostcopyState postcopy_state_set(PostcopyState new_state);
+
+/* ram cache */
+int colo_init_ram_cache(void);
+void colo_release_ram_cache(void);
 #endif
diff --git a/migration/colo.c b/migration/colo.c
index ec43250..0401629 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -287,6 +287,7 @@ void *colo_process_incoming_thread(void *opaque)
 {
     MigrationIncomingState *mis = opaque;
     Error *local_err = NULL;
+    int ret;
 
     migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
                       MIGRATION_STATUS_COLO);
@@ -303,6 +304,12 @@ void *colo_process_incoming_thread(void *opaque)
      */
     qemu_file_set_blocking(mis->from_src_file, true);
 
+    ret = colo_init_ram_cache();
+    if (ret < 0) {
+        error_report("Failed to initialize ram cache");
+        goto out;
+    }
+
     colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
                       &local_err);
     if (local_err) {
@@ -353,6 +360,10 @@ out:
         error_report_err(local_err);
     }
 
+    qemu_mutex_lock_iothread();
+    colo_release_ram_cache();
+    qemu_mutex_unlock_iothread();
+
     if (mis->to_src_file) {
         qemu_fclose(mis->to_src_file);
     }
diff --git a/migration/ram.c b/migration/ram.c
index e9067c5..ac55980 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -227,6 +227,7 @@ static RAMBlock *last_sent_block;
 static ram_addr_t last_offset;
 static QemuMutex migration_bitmap_mutex;
 static uint64_t migration_dirty_pages;
+static bool ram_cache_enable;
 static uint32_t last_version;
 static bool ram_bulk_stage;
 
@@ -2186,6 +2187,20 @@ static inline void *host_from_ram_block_offset(RAMBlock *block,
     return block->host + offset;
 }
 
+static inline void *colo_cache_from_block_offset(RAMBlock *block,
+                                                 ram_addr_t offset)
+{
+    if (!offset_in_ramblock(block, offset)) {
+        return NULL;
+    }
+    if (!block->colo_cache) {
+        error_report("%s: colo_cache is NULL in block :%s",
+                     __func__, block->idstr);
+        return NULL;
+    }
+    return block->colo_cache + offset;
+}
+
 /*
  * If a page (or a whole RDMA chunk) has been
  * determined to be zero, then zap it.
@@ -2501,7 +2516,12 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
                      RAM_SAVE_FLAG_COMPRESS_PAGE | RAM_SAVE_FLAG_XBZRLE)) {
             RAMBlock *block = ram_block_from_stream(f, flags);
 
-            host = host_from_ram_block_offset(block, addr);
+            /* After going into COLO, we should load the Page into colo_cache */
+            if (ram_cache_enable) {
+                host = colo_cache_from_block_offset(block, addr);
+            } else {
+                host = host_from_ram_block_offset(block, addr);
+            }
             if (!host) {
                 error_report("Illegal RAM offset " RAM_ADDR_FMT, addr);
                 ret = -EINVAL;
@@ -2597,6 +2617,57 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
     return ret;
 }
 
+/*
+ * colo cache: this is for secondary VM, we cache the whole
+ * memory of the secondary VM, it will be called after first migration.
+ */
+int colo_init_ram_cache(void)
+{
+    RAMBlock *block;
+
+    rcu_read_lock();
+    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+        block->colo_cache = qemu_anon_ram_alloc(block->used_length, NULL);
+        if (!block->colo_cache) {
+            error_report("%s: Can't alloc memory for COLO cache of block %s,"
+                         "size 0x" RAM_ADDR_FMT, __func__, block->idstr,
+                         block->used_length);
+            goto out_locked;
+        }
+        memcpy(block->colo_cache, block->host, block->used_length);
+    }
+    rcu_read_unlock();
+    ram_cache_enable = true;
+    return 0;
+
+out_locked:
+    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+        if (block->colo_cache) {
+            qemu_anon_ram_free(block->colo_cache, block->used_length);
+            block->colo_cache = NULL;
+        }
+    }
+
+    rcu_read_unlock();
+    return -errno;
+}
+
+void colo_release_ram_cache(void)
+{
+    RAMBlock *block;
+
+    ram_cache_enable = false;
+
+    rcu_read_lock();
+    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
+        if (block->colo_cache) {
+            qemu_anon_ram_free(block->colo_cache, block->used_length);
+            block->colo_cache = NULL;
+        }
+    }
+    rcu_read_unlock();
+}
+
 static SaveVMHandlers savevm_ram_handlers = {
     .save_live_setup = ram_save_setup,
     .save_live_iterate = ram_save_iterate,
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 11/34] ram/COLO: Record the dirty pages that SVM received

[zhanghailiang]

We record the address of the dirty pages that received,
it will help flushing pages that cached into SVM.
We record them by re-using migration dirty bitmap.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v16:
- Use the new wrapper memory_region_get_ram_addr() modified in commit 7ebb2745
v12:
- Add Reviewed-by tag
v11:
- Split a new helper function from original
  host_from_stream_offset() (Dave's suggestion)
- Only do recording work in this patch
v10:
- New patch split from v9's patch 13
- Rebase to master to use 'migration_bitmap_rcu'
---
 migration/ram.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/migration/ram.c b/migration/ram.c
index ac55980..99449c3 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2190,6 +2190,9 @@ static inline void *host_from_ram_block_offset(RAMBlock *block,
 static inline void *colo_cache_from_block_offset(RAMBlock *block,
                                                  ram_addr_t offset)
 {
+    unsigned long *bitmap;
+    long k;
+
     if (!offset_in_ramblock(block, offset)) {
         return NULL;
     }
@@ -2198,6 +2201,17 @@ static inline void *colo_cache_from_block_offset(RAMBlock *block,
                      __func__, block->idstr);
         return NULL;
     }
+
+    k = (memory_region_get_ram_addr(block->mr) + offset) >> TARGET_PAGE_BITS;
+    bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap;
+    /*
+    * During colo checkpoint, we need bitmap of these migrated pages.
+    * It help us to decide which pages in ram cache should be flushed
+    * into VM's RAM later.
+    */
+    if (!test_and_set_bit(k, bitmap)) {
+        migration_dirty_pages++;
+    }
     return block->colo_cache + offset;
 }
 
@@ -2624,6 +2638,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
 int colo_init_ram_cache(void)
 {
     RAMBlock *block;
+    int64_t ram_cache_pages = last_ram_offset() >> TARGET_PAGE_BITS;
 
     rcu_read_lock();
     QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
@@ -2638,6 +2653,15 @@ int colo_init_ram_cache(void)
     }
     rcu_read_unlock();
     ram_cache_enable = true;
+    /*
+    * Record the dirty pages that sent by PVM, we use this dirty bitmap together
+    * with to decide which page in cache should be flushed into SVM's RAM. Here
+    * we use the same name 'migration_bitmap_rcu' as for migration.
+    */
+    migration_bitmap_rcu = g_new0(struct BitmapRcu, 1);
+    migration_bitmap_rcu->bmap = bitmap_new(ram_cache_pages);
+    migration_dirty_pages = 0;
+
     return 0;
 
 out_locked:
@@ -2655,9 +2679,15 @@ out_locked:
 void colo_release_ram_cache(void)
 {
     RAMBlock *block;
+    struct BitmapRcu *bitmap = migration_bitmap_rcu;
 
     ram_cache_enable = false;
 
+    atomic_rcu_set(&migration_bitmap_rcu, NULL);
+    if (bitmap) {
+        call_rcu(bitmap, migration_bitmap_free, rcu);
+    }
+
     rcu_read_lock();
     QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
         if (block->colo_cache) {
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 12/34] COLO: Load VMState into buffer before restore it

[zhanghailiang]

We should not destroy the state of SVM (Secondary VM) until we receive
the whole state from the PVM (Primary VM), in case the primary fails in
the middle of sending the state, so, here we cache the device state in
Secondary before restore it.

Besides, we should call qemu_system_reset() before load VM state,
which can ensure the data is intact.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v17:
- Replace the old buffer API with the new channel buffer API.
v16:
- Rename colo_get_cmd_value() to colo_receive_mesage_value();
v13:
- Fix the define of colo_get_cmd_value() to use 'Error **errp' instead of
  return value.
v12:
- Use the new helper colo_get_cmd_value() instead of colo_ctl_get()
---
 migration/colo.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 68 insertions(+), 2 deletions(-)

diff --git a/migration/colo.c b/migration/colo.c
index 0401629..8fa2104 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -115,6 +115,28 @@ static void colo_receive_check_message(QEMUFile *f, COLOMessage expect_msg,
     }
 }
 
+static uint64_t colo_receive_message_value(QEMUFile *f, uint32_t expect_msg,
+                                           Error **errp)
+{
+    Error *local_err = NULL;
+    uint64_t value;
+    int ret;
+
+    colo_receive_check_message(f, expect_msg, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return 0;
+    }
+
+    value = qemu_get_be64(f);
+    ret = qemu_file_get_error(f);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Failed to get value for COLO message: %s",
+                         COLOMessage_lookup[expect_msg]);
+    }
+    return value;
+}
+
 static int colo_do_checkpoint_transaction(MigrationState *s,
                                           QIOChannelBuffer *bioc,
                                           QEMUFile *fb)
@@ -286,6 +308,10 @@ static void colo_wait_handle_message(QEMUFile *f, int *checkpoint_request,
 void *colo_process_incoming_thread(void *opaque)
 {
     MigrationIncomingState *mis = opaque;
+    QEMUFile *fb = NULL;
+    QIOChannelBuffer *bioc = NULL; /* Cache incoming device state */
+    uint64_t total_size;
+    uint64_t value;
     Error *local_err = NULL;
     int ret;
 
@@ -310,6 +336,10 @@ void *colo_process_incoming_thread(void *opaque)
         goto out;
     }
 
+    bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE);
+    fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc));
+    object_unref(OBJECT(bioc));
+
     colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
                       &local_err);
     if (local_err) {
@@ -337,7 +367,30 @@ void *colo_process_incoming_thread(void *opaque)
             goto out;
         }
 
-        /* TODO: read migration data into colo buffer */
+        value = colo_receive_message_value(mis->from_src_file,
+                                 COLO_MESSAGE_VMSTATE_SIZE, &local_err);
+        if (local_err) {
+            goto out;
+        }
+
+        /*
+         * Read VM device state data into channel buffer,
+         * It's better to re-use the memory allocated.
+         * Here we need to handle the channel buffer directly.
+         */
+        if (value > bioc->capacity) {
+            bioc->capacity = value;
+            bioc->data = g_realloc(bioc->data, bioc->capacity);
+        }
+        total_size = qemu_get_buffer(mis->from_src_file, bioc->data, value);
+        if (total_size != value) {
+            error_report("Got %lu VMState data, less than expected %lu",
+                         total_size, value);
+            ret = -EINVAL;
+            goto out;
+        }
+        bioc->usage = total_size;
+        qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL);
 
         colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_RECEIVED,
                      &local_err);
@@ -345,7 +398,16 @@ void *colo_process_incoming_thread(void *opaque)
             goto out;
         }
 
-        /* TODO: load vm state */
+        qemu_mutex_lock_iothread();
+        qemu_system_reset(VMRESET_SILENT);
+        if (qemu_loadvm_state(fb) < 0) {
+            error_report("COLO: loadvm failed");
+            qemu_mutex_unlock_iothread();
+            goto out;
+        }
+        qemu_mutex_unlock_iothread();
+
+        /* TODO: flush vm state */
 
         colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED,
                      &local_err);
@@ -360,6 +422,10 @@ out:
         error_report_err(local_err);
     }
 
+    if (fb) {
+        qemu_fclose(fb);
+    }
+
     qemu_mutex_lock_iothread();
     colo_release_ram_cache();
     qemu_mutex_unlock_iothread();
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH COLO-Frame v18 12/34] COLO: Load VMState into buffer before restore it

[Dr. David Alan Gilbert]

* zhanghailiang (zhang.zhanghailiang@huawei.com) wrote:
> We should not destroy the state of SVM (Secondary VM) until we receive
> the whole state from the PVM (Primary VM), in case the primary fails in
> the middle of sending the state, so, here we cache the device state in
> Secondary before restore it.
> 
> Besides, we should call qemu_system_reset() before load VM state,
> which can ensure the data is intact.
> 
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
> Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
> v17:
> - Replace the old buffer API with the new channel buffer API.
> v16:
> - Rename colo_get_cmd_value() to colo_receive_mesage_value();
> v13:
> - Fix the define of colo_get_cmd_value() to use 'Error **errp' instead of
>   return value.
> v12:
> - Use the new helper colo_get_cmd_value() instead of colo_ctl_get()
> ---
>  migration/colo.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 68 insertions(+), 2 deletions(-)
> 
> diff --git a/migration/colo.c b/migration/colo.c
> index 0401629..8fa2104 100644
> --- a/migration/colo.c
> +++ b/migration/colo.c
> @@ -115,6 +115,28 @@ static void colo_receive_check_message(QEMUFile *f, COLOMessage expect_msg,
>      }
>  }
>  
> +static uint64_t colo_receive_message_value(QEMUFile *f, uint32_t expect_msg,
> +                                           Error **errp)
> +{
> +    Error *local_err = NULL;
> +    uint64_t value;
> +    int ret;
> +
> +    colo_receive_check_message(f, expect_msg, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return 0;
> +    }
> +
> +    value = qemu_get_be64(f);
> +    ret = qemu_file_get_error(f);
> +    if (ret < 0) {
> +        error_setg_errno(errp, -ret, "Failed to get value for COLO message: %s",
> +                         COLOMessage_lookup[expect_msg]);
> +    }
> +    return value;
> +}
> +
>  static int colo_do_checkpoint_transaction(MigrationState *s,
>                                            QIOChannelBuffer *bioc,
>                                            QEMUFile *fb)
> @@ -286,6 +308,10 @@ static void colo_wait_handle_message(QEMUFile *f, int *checkpoint_request,
>  void *colo_process_incoming_thread(void *opaque)
>  {
>      MigrationIncomingState *mis = opaque;
> +    QEMUFile *fb = NULL;
> +    QIOChannelBuffer *bioc = NULL; /* Cache incoming device state */
> +    uint64_t total_size;
> +    uint64_t value;
>      Error *local_err = NULL;
>      int ret;
>  
> @@ -310,6 +336,10 @@ void *colo_process_incoming_thread(void *opaque)
>          goto out;
>      }
>  
> +    bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE);
> +    fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc));
> +    object_unref(OBJECT(bioc));
> +
>      colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
>                        &local_err);
>      if (local_err) {
> @@ -337,7 +367,30 @@ void *colo_process_incoming_thread(void *opaque)
>              goto out;
>          }
>  
> -        /* TODO: read migration data into colo buffer */
> +        value = colo_receive_message_value(mis->from_src_file,
> +                                 COLO_MESSAGE_VMSTATE_SIZE, &local_err);
> +        if (local_err) {
> +            goto out;
> +        }
> +
> +        /*
> +         * Read VM device state data into channel buffer,
> +         * It's better to re-use the memory allocated.
> +         * Here we need to handle the channel buffer directly.
> +         */
> +        if (value > bioc->capacity) {
> +            bioc->capacity = value;
> +            bioc->data = g_realloc(bioc->data, bioc->capacity);
> +        }

Dan: Are you ok with that, or should there be some io/channel-buffer.c call
to do it?

Dave

> +        total_size = qemu_get_buffer(mis->from_src_file, bioc->data, value);
> +        if (total_size != value) {
> +            error_report("Got %lu VMState data, less than expected %lu",
> +                         total_size, value);
> +            ret = -EINVAL;
> +            goto out;
> +        }
> +        bioc->usage = total_size;
> +        qio_channel_io_seek(QIO_CHANNEL(bioc), 0, 0, NULL);
>  
>          colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_RECEIVED,
>                       &local_err);
> @@ -345,7 +398,16 @@ void *colo_process_incoming_thread(void *opaque)
>              goto out;
>          }
>  
> -        /* TODO: load vm state */
> +        qemu_mutex_lock_iothread();
> +        qemu_system_reset(VMRESET_SILENT);
> +        if (qemu_loadvm_state(fb) < 0) {
> +            error_report("COLO: loadvm failed");
> +            qemu_mutex_unlock_iothread();
> +            goto out;
> +        }
> +        qemu_mutex_unlock_iothread();
> +
> +        /* TODO: flush vm state */
>  
>          colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED,
>                       &local_err);
> @@ -360,6 +422,10 @@ out:
>          error_report_err(local_err);
>      }
>  
> +    if (fb) {
> +        qemu_fclose(fb);
> +    }
> +
>      qemu_mutex_lock_iothread();
>      colo_release_ram_cache();
>      qemu_mutex_unlock_iothread();
> -- 
> 1.8.3.1
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH COLO-Frame v18 12/34] COLO: Load VMState into buffer before restore it

[Daniel P. Berrange]

On Fri, Aug 05, 2016 at 06:53:49PM +0100, Dr. David Alan Gilbert wrote:
> * zhanghailiang (zhang.zhanghailiang@huawei.com) wrote:
> > We should not destroy the state of SVM (Secondary VM) until we receive
> > the whole state from the PVM (Primary VM), in case the primary fails in
> > the middle of sending the state, so, here we cache the device state in
> > Secondary before restore it.
> > 
> > Besides, we should call qemu_system_reset() before load VM state,
> > which can ensure the data is intact.
> > 
> > Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> > Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
> > Signed-off-by: Gonglei <arei.gonglei@huawei.com>
> > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > ---
> > v17:
> > - Replace the old buffer API with the new channel buffer API.
> > v16:
> > - Rename colo_get_cmd_value() to colo_receive_mesage_value();
> > v13:
> > - Fix the define of colo_get_cmd_value() to use 'Error **errp' instead of
> >   return value.
> > v12:
> > - Use the new helper colo_get_cmd_value() instead of colo_ctl_get()
> > ---
> >  migration/colo.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++++--
> >  1 file changed, 68 insertions(+), 2 deletions(-)
> > 
> > diff --git a/migration/colo.c b/migration/colo.c
> > index 0401629..8fa2104 100644
> > --- a/migration/colo.c
> > +++ b/migration/colo.c
> > @@ -115,6 +115,28 @@ static void colo_receive_check_message(QEMUFile *f, COLOMessage expect_msg,
> >      }
> >  }
> >  
> > +static uint64_t colo_receive_message_value(QEMUFile *f, uint32_t expect_msg,
> > +                                           Error **errp)
> > +{
> > +    Error *local_err = NULL;
> > +    uint64_t value;
> > +    int ret;
> > +
> > +    colo_receive_check_message(f, expect_msg, &local_err);
> > +    if (local_err) {
> > +        error_propagate(errp, local_err);
> > +        return 0;
> > +    }
> > +
> > +    value = qemu_get_be64(f);
> > +    ret = qemu_file_get_error(f);
> > +    if (ret < 0) {
> > +        error_setg_errno(errp, -ret, "Failed to get value for COLO message: %s",
> > +                         COLOMessage_lookup[expect_msg]);
> > +    }
> > +    return value;
> > +}
> > +
> >  static int colo_do_checkpoint_transaction(MigrationState *s,
> >                                            QIOChannelBuffer *bioc,
> >                                            QEMUFile *fb)
> > @@ -286,6 +308,10 @@ static void colo_wait_handle_message(QEMUFile *f, int *checkpoint_request,
> >  void *colo_process_incoming_thread(void *opaque)
> >  {
> >      MigrationIncomingState *mis = opaque;
> > +    QEMUFile *fb = NULL;
> > +    QIOChannelBuffer *bioc = NULL; /* Cache incoming device state */
> > +    uint64_t total_size;
> > +    uint64_t value;
> >      Error *local_err = NULL;
> >      int ret;
> >  
> > @@ -310,6 +336,10 @@ void *colo_process_incoming_thread(void *opaque)
> >          goto out;
> >      }
> >  
> > +    bioc = qio_channel_buffer_new(COLO_BUFFER_BASE_SIZE);
> > +    fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc));
> > +    object_unref(OBJECT(bioc));
> > +
> >      colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
> >                        &local_err);
> >      if (local_err) {
> > @@ -337,7 +367,30 @@ void *colo_process_incoming_thread(void *opaque)
> >              goto out;
> >          }
> >  
> > -        /* TODO: read migration data into colo buffer */
> > +        value = colo_receive_message_value(mis->from_src_file,
> > +                                 COLO_MESSAGE_VMSTATE_SIZE, &local_err);
> > +        if (local_err) {
> > +            goto out;
> > +        }
> > +
> > +        /*
> > +         * Read VM device state data into channel buffer,
> > +         * It's better to re-use the memory allocated.
> > +         * Here we need to handle the channel buffer directly.
> > +         */
> > +        if (value > bioc->capacity) {
> > +            bioc->capacity = value;
> > +            bioc->data = g_realloc(bioc->data, bioc->capacity);
> > +        }
> 
> Dan: Are you ok with that, or should there be some io/channel-buffer.c call
> to do it?

While we could add APIs for this, I'm perfectly ok with the buffer
being updated directly too, as its a very simple struct.


Regards,
Daniel
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[Qemu-devel] [PATCH COLO-Frame v18 13/34] COLO: Flush PVM's cached RAM into SVM's memory

[zhanghailiang]

During the time of VM's running, PVM may dirty some pages, we will transfer
PVM's dirty pages to SVM and store them into SVM's RAM cache at next checkpoint
time. So, the content of SVM's RAM cache will always be same with PVM's memory
after checkpoint.

Instead of flushing all content of PVM's RAM cache into SVM's MEMORY,
we do this in a more efficient way:
Only flush any page that dirtied by PVM since last checkpoint.
In this way, we can ensure SVM's memory same with PVM's.

Besides, we must ensure flush RAM cache before load device state.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v12:
- Add a trace point in the end of colo_flush_ram_cache() (Dave's suggestion)
- Add Reviewed-by tag
v11:
- Move the place of 'need_flush' (Dave's suggestion)
- Remove unused 'DPRINTF("Flush ram_cache\n")'
v10:
- trace the number of dirty pages that be received.
---
 include/migration/migration.h |  1 +
 migration/colo.c              |  2 --
 migration/ram.c               | 38 ++++++++++++++++++++++++++++++++++++++
 migration/trace-events        |  2 ++
 4 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index 55679b5..8ae5248 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -366,4 +366,5 @@ PostcopyState postcopy_state_set(PostcopyState new_state);
 /* ram cache */
 int colo_init_ram_cache(void);
 void colo_release_ram_cache(void);
+void colo_flush_ram_cache(void);
 #endif
diff --git a/migration/colo.c b/migration/colo.c
index 8fa2104..58bd5e1 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -407,8 +407,6 @@ void *colo_process_incoming_thread(void *opaque)
         }
         qemu_mutex_unlock_iothread();
 
-        /* TODO: flush vm state */
-
         colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED,
                      &local_err);
         if (local_err) {
diff --git a/migration/ram.c b/migration/ram.c
index 99449c3..198dc53 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2499,6 +2499,7 @@ 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++;
 
@@ -2533,6 +2534,7 @@ 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);
             }
@@ -2626,6 +2628,10 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
 
     wait_for_decompress_done();
     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;
@@ -2698,6 +2704,38 @@ void colo_release_ram_cache(void)
     rcu_read_unlock();
 }
 
+/*
+ * Flush content of RAM cache into SVM's memory.
+ * Only flush the pages that be dirtied by PVM or SVM or both.
+ */
+void colo_flush_ram_cache(void)
+{
+    RAMBlock *block = NULL;
+    void *dst_host;
+    void *src_host;
+    ram_addr_t offset = 0;
+
+    trace_colo_flush_ram_cache_begin(migration_dirty_pages);
+    rcu_read_lock();
+    block = QLIST_FIRST_RCU(&ram_list.blocks);
+    while (block) {
+        ram_addr_t ram_addr_abs;
+        offset = migration_bitmap_find_dirty(block, offset, &ram_addr_abs);
+        migration_bitmap_clear_dirty(ram_addr_abs);
+        if (offset >= block->used_length) {
+            offset = 0;
+            block = QLIST_NEXT_RCU(block, next);
+        } else {
+            dst_host = block->host + offset;
+            src_host = block->colo_cache + offset;
+            memcpy(dst_host, src_host, TARGET_PAGE_SIZE);
+        }
+    }
+    rcu_read_unlock();
+    trace_colo_flush_ram_cache_end();
+    assert(migration_dirty_pages == 0);
+}
+
 static SaveVMHandlers savevm_ram_handlers = {
     .save_live_setup = ram_save_setup,
     .save_live_iterate = ram_save_iterate,
diff --git a/migration/trace-events b/migration/trace-events
index e98eaef..82dc7a0 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -65,6 +65,8 @@ migration_throttle(void) ""
 ram_load_postcopy_loop(uint64_t addr, int flags) "@%" PRIx64 " %x"
 ram_postcopy_send_discard_bitmap(void) ""
 ram_save_queue_pages(const char *rbname, size_t start, size_t len) "%s: start: %zx len: %zx"
+colo_flush_ram_cache_begin(uint64_t dirty_pages) "dirty_pages %" PRIu64
+colo_flush_ram_cache_end(void) ""
 
 # migration/migration.c
 await_return_path_close_on_source_close(void) ""
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 14/34] COLO: Add checkpoint-delay parameter for migrate-set-parameters

[zhanghailiang]

Add checkpoint-delay parameter for migrate-set-parameters, so that
we can control the checkpoint frequency when COLO is in periodic mode.

Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v12:
- Change checkpoint-delay to x-checkpoint-delay (Dave's suggestion)
- Add Reviewed-by tag
v11:
- Move this patch ahead of the patch where uses 'checkpoint_delay'
 (Dave's suggestion)
v10:
- Fix related qmp command
---
 hmp.c                 |  7 +++++++
 migration/migration.c | 18 ++++++++++++++++++
 qapi-schema.json      | 17 ++++++++++++++---
 qmp-commands.hx       |  3 ++-
 4 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/hmp.c b/hmp.c
index cc2056e..38b4a51 100644
--- a/hmp.c
+++ b/hmp.c
@@ -304,6 +304,9 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, " %s: '%s'",
             MigrationParameter_lookup[MIGRATION_PARAMETER_TLS_HOSTNAME],
             params->tls_hostname ? : "");
+        monitor_printf(mon, " %s: %" PRId64,
+            MigrationParameter_lookup[MIGRATION_PARAMETER_X_CHECKPOINT_DELAY],
+            params->x_checkpoint_delay);
         monitor_printf(mon, "\n");
     }
 
@@ -1261,6 +1264,7 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
     bool has_tls_creds = false;
     bool has_tls_hostname = false;
     bool use_int_value = false;
+    bool has_x_checkpoint_delay = false;
     int i;
 
     for (i = 0; i < MIGRATION_PARAMETER__MAX; i++) {
@@ -1284,6 +1288,8 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
                 break;
             case MIGRATION_PARAMETER_CPU_THROTTLE_INCREMENT:
                 has_cpu_throttle_increment = true;
+            case MIGRATION_PARAMETER_X_CHECKPOINT_DELAY:
+                has_x_checkpoint_delay = true;
                 break;
             case MIGRATION_PARAMETER_TLS_CREDS:
                 has_tls_creds = true;
@@ -1308,6 +1314,7 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
                                        has_cpu_throttle_increment, valueint,
                                        has_tls_creds, valuestr,
                                        has_tls_hostname, valuestr,
+                                       has_x_checkpoint_delay, valueint,
                                        &err);
             break;
         }
diff --git a/migration/migration.c b/migration/migration.c
index e5f47d0..3358980 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -59,6 +59,11 @@
 /* Migration XBZRLE default cache size */
 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)
 
+/* The delay time (in ms) between two COLO checkpoints
+ * Note: Please change this default value to 10000 when we support hybrid mode.
+ */
+#define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY 200
+
 static NotifierList migration_state_notifiers =
     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
 
@@ -90,6 +95,7 @@ MigrationState *migrate_get_current(void)
             .decompress_threads = DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT,
             .cpu_throttle_initial = DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL,
             .cpu_throttle_increment = DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT,
+            .x_checkpoint_delay = DEFAULT_MIGRATE_X_CHECKPOINT_DELAY,
         },
     };
 
@@ -582,6 +588,7 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
     params->cpu_throttle_increment = s->parameters.cpu_throttle_increment;
     params->tls_creds = g_strdup(s->parameters.tls_creds);
     params->tls_hostname = g_strdup(s->parameters.tls_hostname);
+    params->x_checkpoint_delay = s->parameters.x_checkpoint_delay;
 
     return params;
 }
@@ -801,6 +808,8 @@ void qmp_migrate_set_parameters(bool has_compress_level,
                                 const char *tls_creds,
                                 bool has_tls_hostname,
                                 const char *tls_hostname,
+                                bool has_x_checkpoint_delay,
+                                int64_t x_checkpoint_delay,
                                 Error **errp)
 {
     MigrationState *s = migrate_get_current();
@@ -836,6 +845,11 @@ void qmp_migrate_set_parameters(bool has_compress_level,
                    "cpu_throttle_increment",
                    "an integer in the range of 1 to 99");
     }
+    if (has_x_checkpoint_delay && (x_checkpoint_delay < 0)) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
+                    "x_checkpoint_delay",
+                    "is invalid, it should be positive");
+    }
 
     if (has_compress_level) {
         s->parameters.compress_level = compress_level;
@@ -860,6 +874,10 @@ void qmp_migrate_set_parameters(bool has_compress_level,
         g_free(s->parameters.tls_hostname);
         s->parameters.tls_hostname = g_strdup(tls_hostname);
     }
+
+    if (has_x_checkpoint_delay) {
+        s->parameters.x_checkpoint_delay = x_checkpoint_delay;
+    }
 }
 
 
diff --git a/qapi-schema.json b/qapi-schema.json
index 0ff1a63..7c0639d 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -646,12 +646,16 @@
 #                hostname must be provided so that the server's x509
 #                certificate identity can be validated. (Since 2.7)
 #
+# @x-checkpoint-delay: The delay time (in ms) between two COLO checkpoints in
+#          periodic mode. (Since 2.8)
+#
 # Since: 2.4
 ##
 { 'enum': 'MigrationParameter',
   'data': ['compress-level', 'compress-threads', 'decompress-threads',
            'cpu-throttle-initial', 'cpu-throttle-increment',
-           'tls-creds', 'tls-hostname'] }
+           'tls-creds', 'tls-hostname',
+           'x-checkpoint-delay' ] }
 
 #
 # @migrate-set-parameters
@@ -687,6 +691,8 @@
 #                hostname must be provided so that the server's x509
 #                certificate identity can be validated. (Since 2.7)
 #
+# @x-checkpoint-delay: the delay time between two checkpoints. (Since 2.8)
+#
 # Since: 2.4
 ##
 { 'command': 'migrate-set-parameters',
@@ -696,7 +702,8 @@
             '*cpu-throttle-initial': 'int',
             '*cpu-throttle-increment': 'int',
             '*tls-creds': 'str',
-            '*tls-hostname': 'str'} }
+            '*tls-hostname': 'str',
+            '*x-checkpoint-delay': 'int' } }
 
 #
 # @MigrationParameters
@@ -730,6 +737,8 @@
 #                hostname must be provided so that the server's x509
 #                certificate identity can be validated. (Since 2.7)
 #
+# @x-checkpoint-delay: the delay time between two COLO checkpoints. (Since 2.8)
+#
 # Since: 2.4
 ##
 { 'struct': 'MigrationParameters',
@@ -739,7 +748,9 @@
             'cpu-throttle-initial': 'int',
             'cpu-throttle-increment': 'int',
             'tls-creds': 'str',
-            'tls-hostname': 'str'} }
+            'tls-hostname': 'str',
+            'x-checkpoint-delay': 'int'} }
+
 ##
 # @query-migrate-parameters
 #
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 6a470d3..88e3870 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3790,6 +3790,7 @@ Set migration parameters
                           throttled for auto-converge (json-int)
 - "cpu-throttle-increment": set throttle increasing percentage for
                             auto-converge (json-int)
+- "x-checkpoint-delay": set the delay time for periodic checkpoint (json-int)
 
 Arguments:
 
@@ -3803,7 +3804,7 @@ EQMP
     {
         .name       = "migrate-set-parameters",
         .args_type  =
-            "compress-level:i?,compress-threads:i?,decompress-threads:i?,cpu-throttle-initial:i?,cpu-throttle-increment:i?",
+            "compress-level:i?,compress-threads:i?,decompress-threads:i?,cpu-throttle-initial:i?,cpu-throttle-increment:i?,x-checkpoint-delay:i?",
         .mhandler.cmd_new = qmp_marshal_migrate_set_parameters,
     },
 SQMP
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 15/34] COLO: Synchronize PVM's state to SVM periodically

[zhanghailiang]

Do checkpoint periodically, the default interval is 200ms.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v12:
- Add Reviewed-by tag
v11:
- Fix wrong sleep time for checkpoint period. (Dave's comment)
---
 migration/colo.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/migration/colo.c b/migration/colo.c
index 58bd5e1..cdf5dc9 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -11,6 +11,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu/timer.h"
 #include "sysemu/sysemu.h"
 #include "migration/colo.h"
 #include "io/channel-buffer.h"
@@ -226,6 +227,7 @@ static void colo_process_checkpoint(MigrationState *s)
 {
     QIOChannelBuffer *bioc;
     QEMUFile *fb = NULL;
+    int64_t current_time, checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
     Error *local_err = NULL;
     int ret;
 
@@ -254,10 +256,20 @@ static void colo_process_checkpoint(MigrationState *s)
     trace_colo_vm_state_change("stop", "run");
 
     while (s->state == MIGRATION_STATUS_COLO) {
+        current_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
+        if (current_time - checkpoint_time <
+            s->parameters.x_checkpoint_delay) {
+            int64_t delay_ms;
+
+            delay_ms = s->parameters.x_checkpoint_delay -
+                       (current_time - checkpoint_time);
+            g_usleep(delay_ms * 1000);
+        }
         ret = colo_do_checkpoint_transaction(s, bioc, fb);
         if (ret < 0) {
             goto out;
         }
+        checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
     }
 
 out:
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 16/34] COLO failover: Introduce a new command to trigger a failover

[zhanghailiang]

We leave users to choose whatever heartbeat solution they want, if the heartbeat
is lost, or other errors they detect, they can use experimental command
'x_colo_lost_heartbeat' to tell COLO to do failover, COLO will do operations
accordingly.

For example, if the command is sent to the PVM, the Primary side will
exit COLO mode and take over operation. If sent to the Secondary, the
secondary will run failover work, then take over server operation to
become the new Primary.

Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Eric Blake <eblake@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v16:
- Fix compile broken due to missing osdep.h
v13:
- Add Reviewed-by tag
v11:
- Add more comments for x-colo-lost-heartbeat command (Eric's suggestion)
- Return 'enum' instead of 'int' for get_colo_mode() (Eric's suggestion)
v10:
- Rename command colo_lost_hearbeat to experimental 'x_colo_lost_heartbeat'
---
 hmp-commands.hx              | 15 +++++++++++++++
 hmp.c                        |  8 ++++++++
 hmp.h                        |  1 +
 include/migration/colo.h     |  3 +++
 include/migration/failover.h | 20 ++++++++++++++++++++
 migration/Makefile.objs      |  2 +-
 migration/colo-comm.c        | 11 +++++++++++
 migration/colo-failover.c    | 42 ++++++++++++++++++++++++++++++++++++++++++
 migration/colo.c             |  1 +
 qapi-schema.json             | 29 +++++++++++++++++++++++++++++
 qmp-commands.hx              | 19 +++++++++++++++++++
 stubs/migration-colo.c       |  8 ++++++++
 12 files changed, 158 insertions(+), 1 deletion(-)
 create mode 100644 include/migration/failover.h
 create mode 100644 migration/colo-failover.c

diff --git a/hmp-commands.hx b/hmp-commands.hx
index 848efee..c2f1ab0 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1040,6 +1040,21 @@ migration (or once already in postcopy).
 ETEXI
 
     {
+        .name       = "x_colo_lost_heartbeat",
+        .args_type  = "",
+        .params     = "",
+        .help       = "Tell COLO that heartbeat is lost,\n\t\t\t"
+                      "a failover or takeover is needed.",
+        .mhandler.cmd = hmp_x_colo_lost_heartbeat,
+    },
+
+STEXI
+@item x_colo_lost_heartbeat
+@findex x_colo_lost_heartbeat
+Tell COLO that heartbeat is lost, a failover or takeover is needed.
+ETEXI
+
+    {
         .name       = "client_migrate_info",
         .args_type  = "protocol:s,hostname:s,port:i?,tls-port:i?,cert-subject:s?",
         .params     = "protocol hostname port tls-port cert-subject",
diff --git a/hmp.c b/hmp.c
index 38b4a51..16c5fa1 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1354,6 +1354,14 @@ void hmp_migrate_start_postcopy(Monitor *mon, const QDict *qdict)
     hmp_handle_error(mon, &err);
 }
 
+void hmp_x_colo_lost_heartbeat(Monitor *mon, const QDict *qdict)
+{
+    Error *err = NULL;
+
+    qmp_x_colo_lost_heartbeat(&err);
+    hmp_handle_error(mon, &err);
+}
+
 void hmp_set_password(Monitor *mon, const QDict *qdict)
 {
     const char *protocol  = qdict_get_str(qdict, "protocol");
diff --git a/hmp.h b/hmp.h
index 0876ec0..0457c8a 100644
--- a/hmp.h
+++ b/hmp.h
@@ -70,6 +70,7 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_cache_size(Monitor *mon, const QDict *qdict);
 void hmp_client_migrate_info(Monitor *mon, const QDict *qdict);
 void hmp_migrate_start_postcopy(Monitor *mon, const QDict *qdict);
+void hmp_x_colo_lost_heartbeat(Monitor *mon, const QDict *qdict);
 void hmp_set_password(Monitor *mon, const QDict *qdict);
 void hmp_expire_password(Monitor *mon, const QDict *qdict);
 void hmp_eject(Monitor *mon, const QDict *qdict);
diff --git a/include/migration/colo.h b/include/migration/colo.h
index b40676c..e9ac2c3 100644
--- a/include/migration/colo.h
+++ b/include/migration/colo.h
@@ -17,6 +17,7 @@
 #include "migration/migration.h"
 #include "qemu/coroutine_int.h"
 #include "qemu/thread.h"
+#include "qemu/main-loop.h"
 
 bool colo_supported(void);
 void colo_info_init(void);
@@ -29,4 +30,6 @@ bool migration_incoming_enable_colo(void);
 void migration_incoming_exit_colo(void);
 void *colo_process_incoming_thread(void *opaque);
 bool migration_incoming_in_colo_state(void);
+
+COLOMode get_colo_mode(void);
 #endif
diff --git a/include/migration/failover.h b/include/migration/failover.h
new file mode 100644
index 0000000..3274735
--- /dev/null
+++ b/include/migration/failover.h
@@ -0,0 +1,20 @@
+/*
+ *  COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ *  (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO.,LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 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.
+ */
+
+#ifndef QEMU_FAILOVER_H
+#define QEMU_FAILOVER_H
+
+#include "qemu-common.h"
+
+void failover_request_active(Error **errp);
+
+#endif
diff --git a/migration/Makefile.objs b/migration/Makefile.objs
index 4bbe9ab..3f3e237 100644
--- a/migration/Makefile.objs
+++ b/migration/Makefile.objs
@@ -1,7 +1,7 @@
 common-obj-y += migration.o socket.o fd.o exec.o
 common-obj-y += tls.o
-common-obj-$(CONFIG_COLO) += colo.o
 common-obj-y += colo-comm.o
+common-obj-$(CONFIG_COLO) += colo.o colo-failover.o
 common-obj-y += vmstate.o
 common-obj-y += qemu-file.o
 common-obj-y += qemu-file-channel.o
diff --git a/migration/colo-comm.c b/migration/colo-comm.c
index 1a36893..716a4f7 100644
--- a/migration/colo-comm.c
+++ b/migration/colo-comm.c
@@ -21,6 +21,17 @@ typedef struct {
 
 static COLOInfo colo_info;
 
+COLOMode get_colo_mode(void)
+{
+    if (migration_in_colo_state()) {
+        return COLO_MODE_PRIMARY;
+    } else if (migration_incoming_in_colo_state()) {
+        return COLO_MODE_SECONDARY;
+    } else {
+        return COLO_MODE_UNKNOWN;
+    }
+}
+
 static void colo_info_pre_save(void *opaque)
 {
     COLOInfo *s = opaque;
diff --git a/migration/colo-failover.c b/migration/colo-failover.c
new file mode 100644
index 0000000..413675d
--- /dev/null
+++ b/migration/colo-failover.c
@@ -0,0 +1,42 @@
+/*
+ * COarse-grain LOck-stepping Virtual Machines for Non-stop Service (COLO)
+ * (a.k.a. Fault Tolerance or Continuous Replication)
+ *
+ * Copyright (c) 2016 HUAWEI TECHNOLOGIES CO., LTD.
+ * Copyright (c) 2016 FUJITSU LIMITED
+ * Copyright (c) 2016 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 "qemu/osdep.h"
+#include "migration/colo.h"
+#include "migration/failover.h"
+#include "qmp-commands.h"
+#include "qapi/qmp/qerror.h"
+
+static QEMUBH *failover_bh;
+
+static void colo_failover_bh(void *opaque)
+{
+    qemu_bh_delete(failover_bh);
+    failover_bh = NULL;
+    /*TODO: Do failover work */
+}
+
+void failover_request_active(Error **errp)
+{
+    failover_bh = qemu_bh_new(colo_failover_bh, NULL);
+    qemu_bh_schedule(failover_bh);
+}
+
+void qmp_x_colo_lost_heartbeat(Error **errp)
+{
+    if (get_colo_mode() == COLO_MODE_UNKNOWN) {
+        error_setg(errp, QERR_FEATURE_DISABLED, "colo");
+        return;
+    }
+
+    failover_request_active(errp);
+}
diff --git a/migration/colo.c b/migration/colo.c
index cdf5dc9..b445279 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -18,6 +18,7 @@
 #include "trace.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
+#include "migration/failover.h"
 
 #define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024)
 
diff --git a/qapi-schema.json b/qapi-schema.json
index 7c0639d..ee7131d 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -818,6 +818,35 @@
             'vmstate-send', 'vmstate-size', 'vmstate-received',
             'vmstate-loaded' ] }
 
+##
+# @COLOMode
+#
+# The colo mode
+#
+# @unknown: unknown mode
+#
+# @primary: master side
+#
+# @secondary: slave side
+#
+# Since: 2.8
+##
+{ 'enum': 'COLOMode',
+  'data': [ 'unknown', 'primary', 'secondary'] }
+
+##
+# @x-colo-lost-heartbeat
+#
+# Tell qemu that heartbeat is lost, request it to do takeover procedures.
+# If this command is sent to the PVM, the Primary side will exit COLO mode.
+# If sent to the Secondary, the Secondary side will run failover work,
+# then takes over server operation to become the service VM.
+#
+# Since: 2.8
+##
+{ 'command': 'x-colo-lost-heartbeat' }
+
+##
 # @MouseInfo:
 #
 # Information about a mouse device.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 88e3870..c17728c 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -830,6 +830,25 @@ Example:
 EQMP
 
     {
+        .name       = "x-colo-lost-heartbeat",
+        .args_type  = "",
+        .mhandler.cmd_new = qmp_marshal_x_colo_lost_heartbeat,
+    },
+
+SQMP
+x-colo-lost-heartbeat
+--------------------
+
+Tell COLO that heartbeat is lost, a failover or takeover is needed.
+
+Example:
+
+-> { "execute": "x-colo-lost-heartbeat" }
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "client_migrate_info",
         .args_type  = "protocol:s,hostname:s,port:i?,tls-port:i?,cert-subject:s?",
         .params     = "protocol hostname port tls-port cert-subject",
diff --git a/stubs/migration-colo.c b/stubs/migration-colo.c
index 7b72395..7811764 100644
--- a/stubs/migration-colo.c
+++ b/stubs/migration-colo.c
@@ -12,6 +12,7 @@
 
 #include "qemu/osdep.h"
 #include "migration/colo.h"
+#include "qmp-commands.h"
 
 bool colo_supported(void)
 {
@@ -36,3 +37,10 @@ void *colo_process_incoming_thread(void *opaque)
 {
     return NULL;
 }
+
+void qmp_x_colo_lost_heartbeat(Error **errp)
+{
+    error_setg(errp, "COLO is not supported, please rerun configure"
+                     " with --enable-colo option in order to support"
+                     " COLO feature");
+}
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 17/34] COLO failover: Introduce state to record failover process

[zhanghailiang]

When handling failover, we do different things according to the different stage
of failover process, here we introduce a global atomic variable to record the
status of failover.

We add four failover status to indicate the different stage of failover process.
You should use the helpers to get and set the value.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v11:
- fix several typos found by Dave
- Add Reviewed-by tag
---
 include/migration/failover.h | 10 ++++++++++
 migration/colo-failover.c    | 37 +++++++++++++++++++++++++++++++++++++
 migration/colo.c             |  4 ++++
 migration/trace-events       |  1 +
 4 files changed, 52 insertions(+)

diff --git a/include/migration/failover.h b/include/migration/failover.h
index 3274735..fe71bb4 100644
--- a/include/migration/failover.h
+++ b/include/migration/failover.h
@@ -15,6 +15,16 @@
 
 #include "qemu-common.h"
 
+typedef enum COLOFailoverStatus {
+    FAILOVER_STATUS_NONE = 0,
+    FAILOVER_STATUS_REQUEST = 1, /* Request but not handled */
+    FAILOVER_STATUS_HANDLING = 2, /* In the process of handling failover */
+    FAILOVER_STATUS_COMPLETED = 3, /* Finish the failover process */
+} COLOFailoverStatus;
+
+void failover_init_state(void);
+int failover_set_state(int old_state, int new_state);
+int failover_get_state(void);
 void failover_request_active(Error **errp);
 
 #endif
diff --git a/migration/colo-failover.c b/migration/colo-failover.c
index 413675d..69aac55 100644
--- a/migration/colo-failover.c
+++ b/migration/colo-failover.c
@@ -15,22 +15,59 @@
 #include "migration/failover.h"
 #include "qmp-commands.h"
 #include "qapi/qmp/qerror.h"
+#include "qemu/error-report.h"
+#include "trace.h"
 
 static QEMUBH *failover_bh;
+static COLOFailoverStatus failover_state;
 
 static void colo_failover_bh(void *opaque)
 {
+    int old_state;
+
     qemu_bh_delete(failover_bh);
     failover_bh = NULL;
+    old_state = failover_set_state(FAILOVER_STATUS_REQUEST,
+                                   FAILOVER_STATUS_HANDLING);
+    if (old_state != FAILOVER_STATUS_REQUEST) {
+        error_report("Unkown error for failover, old_state=%d", old_state);
+        return;
+    }
     /*TODO: Do failover work */
 }
 
 void failover_request_active(Error **errp)
 {
+   if (failover_set_state(FAILOVER_STATUS_NONE, FAILOVER_STATUS_REQUEST)
+         != FAILOVER_STATUS_NONE) {
+        error_setg(errp, "COLO failover is already actived");
+        return;
+    }
     failover_bh = qemu_bh_new(colo_failover_bh, NULL);
     qemu_bh_schedule(failover_bh);
 }
 
+void failover_init_state(void)
+{
+    failover_state = FAILOVER_STATUS_NONE;
+}
+
+int failover_set_state(int old_state, int new_state)
+{
+    int old;
+
+    old = atomic_cmpxchg(&failover_state, old_state, new_state);
+    if (old == old_state) {
+        trace_colo_failover_set_state(new_state);
+    }
+    return old;
+}
+
+int failover_get_state(void)
+{
+    return atomic_read(&failover_state);
+}
+
 void qmp_x_colo_lost_heartbeat(Error **errp)
 {
     if (get_colo_mode() == COLO_MODE_UNKNOWN) {
diff --git a/migration/colo.c b/migration/colo.c
index b445279..9afc527 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -232,6 +232,8 @@ static void colo_process_checkpoint(MigrationState *s)
     Error *local_err = NULL;
     int ret;
 
+    failover_init_state();
+
     s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file);
     if (!s->rp_state.from_dst_file) {
         error_report("Open QEMUFile from_dst_file failed");
@@ -331,6 +333,8 @@ void *colo_process_incoming_thread(void *opaque)
     migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
                       MIGRATION_STATUS_COLO);
 
+    failover_init_state();
+
     mis->to_src_file = qemu_file_get_return_path(mis->from_src_file);
     if (!mis->to_src_file) {
         error_report("colo incoming thread: Open QEMUFile to_src_file failed");
diff --git a/migration/trace-events b/migration/trace-events
index 82dc7a0..d9f44ba 100644
--- a/migration/trace-events
+++ b/migration/trace-events
@@ -214,3 +214,4 @@ migration_tls_incoming_handshake_complete(void) ""
 colo_vm_state_change(const char *old, const char *new) "Change '%s' => '%s'"
 colo_send_message(const char *msg) "Send '%s' message"
 colo_receive_message(const char *msg) "Receive '%s' message"
+colo_failover_set_state(int new_state) "new state %d"
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH COLO-Frame v18 17/34] COLO failover: Introduce state to record failover process

[Dr. David Alan Gilbert]

* zhanghailiang (zhang.zhanghailiang@huawei.com) wrote:

> +        error_report("Unkown error for failover, old_state=%d", old_state);

 Tiny typo; 'Unknown'.
Don't bother reposting just for that, we can fix it later; or fix it if
you have to repost anyway.

Dave

> +        return;
> +    }
>      /*TODO: Do failover work */
>  }
>  
>  void failover_request_active(Error **errp)
>  {
> +   if (failover_set_state(FAILOVER_STATUS_NONE, FAILOVER_STATUS_REQUEST)
> +         != FAILOVER_STATUS_NONE) {
> +        error_setg(errp, "COLO failover is already actived");
> +        return;
> +    }
>      failover_bh = qemu_bh_new(colo_failover_bh, NULL);
>      qemu_bh_schedule(failover_bh);
>  }
>  
> +void failover_init_state(void)
> +{
> +    failover_state = FAILOVER_STATUS_NONE;
> +}
> +
> +int failover_set_state(int old_state, int new_state)
> +{
> +    int old;
> +
> +    old = atomic_cmpxchg(&failover_state, old_state, new_state);
> +    if (old == old_state) {
> +        trace_colo_failover_set_state(new_state);
> +    }
> +    return old;
> +}
> +
> +int failover_get_state(void)
> +{
> +    return atomic_read(&failover_state);
> +}
> +
>  void qmp_x_colo_lost_heartbeat(Error **errp)
>  {
>      if (get_colo_mode() == COLO_MODE_UNKNOWN) {
> diff --git a/migration/colo.c b/migration/colo.c
> index b445279..9afc527 100644
> --- a/migration/colo.c
> +++ b/migration/colo.c
> @@ -232,6 +232,8 @@ static void colo_process_checkpoint(MigrationState *s)
>      Error *local_err = NULL;
>      int ret;
>  
> +    failover_init_state();
> +
>      s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file);
>      if (!s->rp_state.from_dst_file) {
>          error_report("Open QEMUFile from_dst_file failed");
> @@ -331,6 +333,8 @@ void *colo_process_incoming_thread(void *opaque)
>      migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
>                        MIGRATION_STATUS_COLO);
>  
> +    failover_init_state();
> +
>      mis->to_src_file = qemu_file_get_return_path(mis->from_src_file);
>      if (!mis->to_src_file) {
>          error_report("colo incoming thread: Open QEMUFile to_src_file failed");
> diff --git a/migration/trace-events b/migration/trace-events
> index 82dc7a0..d9f44ba 100644
> --- a/migration/trace-events
> +++ b/migration/trace-events
> @@ -214,3 +214,4 @@ migration_tls_incoming_handshake_complete(void) ""
>  colo_vm_state_change(const char *old, const char *new) "Change '%s' => '%s'"
>  colo_send_message(const char *msg) "Send '%s' message"
>  colo_receive_message(const char *msg) "Receive '%s' message"
> +colo_failover_set_state(int new_state) "new state %d"
> -- 
> 1.8.3.1
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

Re: [Qemu-devel] [PATCH COLO-Frame v18 17/34] COLO failover: Introduce state to record failover process

[Hailiang Zhang]

On 2016/8/9 17:17, Dr. David Alan Gilbert wrote:
> * zhanghailiang (zhang.zhanghailiang@huawei.com) wrote:
>
>> +        error_report("Unkown error for failover, old_state=%d", old_state);
>
>   Tiny typo; 'Unknown'.
> Don't bother reposting just for that, we can fix it later; or fix it if
> you have to repost anyway.
>

OK, thanks.

> Dave
>
>> +        return;
>> +    }
>>       /*TODO: Do failover work */
>>   }
>>
>>   void failover_request_active(Error **errp)
>>   {
>> +   if (failover_set_state(FAILOVER_STATUS_NONE, FAILOVER_STATUS_REQUEST)
>> +         != FAILOVER_STATUS_NONE) {
>> +        error_setg(errp, "COLO failover is already actived");
>> +        return;
>> +    }
>>       failover_bh = qemu_bh_new(colo_failover_bh, NULL);
>>       qemu_bh_schedule(failover_bh);
>>   }
>>
>> +void failover_init_state(void)
>> +{
>> +    failover_state = FAILOVER_STATUS_NONE;
>> +}
>> +
>> +int failover_set_state(int old_state, int new_state)
>> +{
>> +    int old;
>> +
>> +    old = atomic_cmpxchg(&failover_state, old_state, new_state);
>> +    if (old == old_state) {
>> +        trace_colo_failover_set_state(new_state);
>> +    }
>> +    return old;
>> +}
>> +
>> +int failover_get_state(void)
>> +{
>> +    return atomic_read(&failover_state);
>> +}
>> +
>>   void qmp_x_colo_lost_heartbeat(Error **errp)
>>   {
>>       if (get_colo_mode() == COLO_MODE_UNKNOWN) {
>> diff --git a/migration/colo.c b/migration/colo.c
>> index b445279..9afc527 100644
>> --- a/migration/colo.c
>> +++ b/migration/colo.c
>> @@ -232,6 +232,8 @@ static void colo_process_checkpoint(MigrationState *s)
>>       Error *local_err = NULL;
>>       int ret;
>>
>> +    failover_init_state();
>> +
>>       s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file);
>>       if (!s->rp_state.from_dst_file) {
>>           error_report("Open QEMUFile from_dst_file failed");
>> @@ -331,6 +333,8 @@ void *colo_process_incoming_thread(void *opaque)
>>       migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
>>                         MIGRATION_STATUS_COLO);
>>
>> +    failover_init_state();
>> +
>>       mis->to_src_file = qemu_file_get_return_path(mis->from_src_file);
>>       if (!mis->to_src_file) {
>>           error_report("colo incoming thread: Open QEMUFile to_src_file failed");
>> diff --git a/migration/trace-events b/migration/trace-events
>> index 82dc7a0..d9f44ba 100644
>> --- a/migration/trace-events
>> +++ b/migration/trace-events
>> @@ -214,3 +214,4 @@ migration_tls_incoming_handshake_complete(void) ""
>>   colo_vm_state_change(const char *old, const char *new) "Change '%s' => '%s'"
>>   colo_send_message(const char *msg) "Send '%s' message"
>>   colo_receive_message(const char *msg) "Receive '%s' message"
>> +colo_failover_set_state(int new_state) "new state %d"
>> --
>> 1.8.3.1
>>
>>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>
> .
>

[Qemu-devel] [PATCH COLO-Frame v18 18/34] COLO: Implement failover work for Primary VM

[zhanghailiang]

For PVM, if there is failover request from users.
The COLO thread will exit the loop while the failover BH does the
cleanup work and resumes VM.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v13:
- Add Reviewed-by tag
v12:
- Fix error report and remove unnecessary check in
  primary_vm_do_failover() (Dave's suggestion)
v11:
- Don't call migration_end() in primary_vm_do_failover(),
 The cleanup work will be done in migration_thread().
- Remove vm_start() in primary_vm_do_failover() which also been
  done in migraiton_thread()
v10:
- Call migration_end() in primary_vm_do_failover()
---
 include/migration/colo.h     |  3 +++
 include/migration/failover.h |  1 +
 migration/colo-failover.c    |  7 +++++-
 migration/colo.c             | 54 ++++++++++++++++++++++++++++++++++++++++++--
 4 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/include/migration/colo.h b/include/migration/colo.h
index e9ac2c3..e32eef4 100644
--- a/include/migration/colo.h
+++ b/include/migration/colo.h
@@ -32,4 +32,7 @@ void *colo_process_incoming_thread(void *opaque);
 bool migration_incoming_in_colo_state(void);
 
 COLOMode get_colo_mode(void);
+
+/* failover */
+void colo_do_failover(MigrationState *s);
 #endif
diff --git a/include/migration/failover.h b/include/migration/failover.h
index fe71bb4..c4bd81e 100644
--- a/include/migration/failover.h
+++ b/include/migration/failover.h
@@ -26,5 +26,6 @@ void failover_init_state(void);
 int failover_set_state(int old_state, int new_state);
 int failover_get_state(void);
 void failover_request_active(Error **errp);
+bool failover_request_is_active(void);
 
 #endif
diff --git a/migration/colo-failover.c b/migration/colo-failover.c
index 69aac55..fa84172 100644
--- a/migration/colo-failover.c
+++ b/migration/colo-failover.c
@@ -33,7 +33,7 @@ static void colo_failover_bh(void *opaque)
         error_report("Unkown error for failover, old_state=%d", old_state);
         return;
     }
-    /*TODO: Do failover work */
+    colo_do_failover(NULL);
 }
 
 void failover_request_active(Error **errp)
@@ -68,6 +68,11 @@ int failover_get_state(void)
     return atomic_read(&failover_state);
 }
 
+bool failover_request_is_active(void)
+{
+    return failover_get_state() != FAILOVER_STATUS_NONE;
+}
+
 void qmp_x_colo_lost_heartbeat(Error **errp)
 {
     if (get_colo_mode() == COLO_MODE_UNKNOWN) {
diff --git a/migration/colo.c b/migration/colo.c
index 9afc527..a4fe334 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -41,6 +41,40 @@ bool migration_incoming_in_colo_state(void)
     return mis && (mis->state == MIGRATION_STATUS_COLO);
 }
 
+static bool colo_runstate_is_stopped(void)
+{
+    return runstate_check(RUN_STATE_COLO) || !runstate_is_running();
+}
+
+static void primary_vm_do_failover(void)
+{
+    MigrationState *s = migrate_get_current();
+    int old_state;
+
+    migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
+                      MIGRATION_STATUS_COMPLETED);
+
+    old_state = failover_set_state(FAILOVER_STATUS_HANDLING,
+                                   FAILOVER_STATUS_COMPLETED);
+    if (old_state != FAILOVER_STATUS_HANDLING) {
+        error_report("Incorrect state (%d) while doing failover for Primary VM",
+                     old_state);
+        return;
+    }
+}
+
+void colo_do_failover(MigrationState *s)
+{
+    /* Make sure VM stopped while failover happened. */
+    if (!colo_runstate_is_stopped()) {
+        vm_stop_force_state(RUN_STATE_COLO);
+    }
+
+    if (get_colo_mode() == COLO_MODE_PRIMARY) {
+        primary_vm_do_failover();
+    }
+}
+
 static void colo_send_message(QEMUFile *f, COLOMessage msg,
                               Error **errp)
 {
@@ -162,9 +196,20 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     bioc->usage = 0;
 
     qemu_mutex_lock_iothread();
+    if (failover_request_is_active()) {
+        qemu_mutex_unlock_iothread();
+        goto out;
+    }
     vm_stop_force_state(RUN_STATE_COLO);
     qemu_mutex_unlock_iothread();
     trace_colo_vm_state_change("run", "stop");
+    /*
+     * Failover request bh could be called after vm_stop_force_state(),
+     * So we need check failover_request_is_active() again.
+     */
+    if (failover_request_is_active()) {
+        goto out;
+    }
 
     /* Disable block migration */
     s->params.blk = 0;
@@ -259,6 +304,11 @@ static void colo_process_checkpoint(MigrationState *s)
     trace_colo_vm_state_change("stop", "run");
 
     while (s->state == MIGRATION_STATUS_COLO) {
+        if (failover_request_is_active()) {
+            error_report("failover request");
+            goto out;
+        }
+
         current_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
         if (current_time - checkpoint_time <
             s->parameters.x_checkpoint_delay) {
@@ -280,9 +330,9 @@ out:
     if (local_err) {
         error_report_err(local_err);
     }
-    migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
-                      MIGRATION_STATUS_COMPLETED);
+
     qemu_fclose(fb);
+
     if (s->rp_state.from_dst_file) {
         qemu_fclose(s->rp_state.from_dst_file);
     }
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 19/34] COLO: Implement failover work for Secondary VM

[zhanghailiang]

If users require SVM to takeover work, colo incoming thread should
exit from loop while failover BH helps backing to migration incoming
coroutine.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v12:
- Improve error message that suggested by Dave
- Add Reviewed-by tag
---
 migration/colo.c | 42 +++++++++++++++++++++++++++++++++++++++---
 1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/migration/colo.c b/migration/colo.c
index a4fe334..eeef775 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -46,6 +46,33 @@ static bool colo_runstate_is_stopped(void)
     return runstate_check(RUN_STATE_COLO) || !runstate_is_running();
 }
 
+static void secondary_vm_do_failover(void)
+{
+    int old_state;
+    MigrationIncomingState *mis = migration_incoming_get_current();
+
+    migrate_set_state(&mis->state, MIGRATION_STATUS_COLO,
+                      MIGRATION_STATUS_COMPLETED);
+
+    if (!autostart) {
+        error_report("\"-S\" qemu option will be ignored in secondary side");
+        /* recover runstate to normal migration finish state */
+        autostart = true;
+    }
+
+    old_state = failover_set_state(FAILOVER_STATUS_HANDLING,
+                                   FAILOVER_STATUS_COMPLETED);
+    if (old_state != FAILOVER_STATUS_HANDLING) {
+        error_report("Incorrect state (%d) while doing failover for "
+                     "secondary VM", old_state);
+        return;
+    }
+    /* For Secondary VM, jump to incoming co */
+    if (mis->migration_incoming_co) {
+        qemu_coroutine_enter(mis->migration_incoming_co);
+    }
+}
+
 static void primary_vm_do_failover(void)
 {
     MigrationState *s = migrate_get_current();
@@ -72,6 +99,8 @@ void colo_do_failover(MigrationState *s)
 
     if (get_colo_mode() == COLO_MODE_PRIMARY) {
         primary_vm_do_failover();
+    } else {
+        secondary_vm_do_failover();
     }
 }
 
@@ -421,6 +450,11 @@ void *colo_process_incoming_thread(void *opaque)
             goto out;
         }
         assert(request);
+        if (failover_request_is_active()) {
+            error_report("failover request");
+            goto out;
+        }
+
         /* FIXME: This is unnecessary for periodic checkpoint mode */
         colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_REPLY,
                      &local_err);
@@ -490,10 +524,12 @@ out:
     if (fb) {
         qemu_fclose(fb);
     }
-
-    qemu_mutex_lock_iothread();
+    /*
+     * We can ensure BH is hold the global lock, and will join COLO
+     * incoming thread, so here it is not necessary to lock here again,
+     * Or there will be a deadlock error.
+     */
     colo_release_ram_cache();
-    qemu_mutex_unlock_iothread();
 
     if (mis->to_src_file) {
         qemu_fclose(mis->to_src_file);
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 20/34] qmp event: Add COLO_EXIT event to notify users while exited from COLO

[zhanghailiang]

If some errors happen during VM's COLO FT stage, it's important to
notify the users of this event. Together with 'x_colo_lost_heartbeat',
Users can intervene in COLO's failover work immediately.
If users don't want to get involved in COLO's failover verdict,
it is still necessary to notify users that we exited COLO mode.

Cc: Markus Armbruster <armbru@redhat.com>
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
v16:
- fix some minor grammars from Eric
- Add Reviewed-by tag
v13:
- Remove optional 'error' string for this event.
  (I doubted it was usefull for users, Since users shouldn't
   interpret it and can't depend on it to decide what happened
   exaclty. Besides it is really hard to organize.)
- Remove unused 'unknown' member for enum COLOExitReason.
 (Eric's suggestion)
- Fix comment for COLO_EXIT
v11:
- Fix several typos found by Eric
---
 docs/qmp-events.txt | 16 ++++++++++++++++
 migration/colo.c    | 19 +++++++++++++++++++
 qapi-schema.json    | 14 ++++++++++++++
 qapi/event.json     | 15 +++++++++++++++
 4 files changed, 64 insertions(+)

diff --git a/docs/qmp-events.txt b/docs/qmp-events.txt
index 7967ec4..02dd521 100644
--- a/docs/qmp-events.txt
+++ b/docs/qmp-events.txt
@@ -188,6 +188,22 @@ Example:
 Note: The "ready to complete" status is always reset by a BLOCK_JOB_ERROR
 event.
 
+COLO_EXIT
+---------
+
+Emitted when VM finishes COLO mode due to some errors happening or
+at the request of users.
+
+Data:
+
+ - "mode": COLO mode, primary or secondary side (json-string)
+ - "reason": the exit reason, internal error or external request. (json-string)
+
+Example:
+
+{"timestamp": {"seconds": 2032141960, "microseconds": 417172},
+ "event": "COLO_EXIT", "data": {"mode": "primary", "reason": "request" } }
+
 DEVICE_DELETED
 --------------
 
diff --git a/migration/colo.c b/migration/colo.c
index eeef775..f8fce0d 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -19,6 +19,7 @@
 #include "qemu/error-report.h"
 #include "qapi/error.h"
 #include "migration/failover.h"
+#include "qapi-event.h"
 
 #define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024)
 
@@ -361,6 +362,17 @@ out:
     }
 
     qemu_fclose(fb);
+    /*
+     * There are only two reasons we can go here, some error happened.
+     * Or the user triggered failover.
+     */
+    if (!failover_request_is_active()) {
+        qapi_event_send_colo_exit(COLO_MODE_PRIMARY,
+                                  COLO_EXIT_REASON_ERROR, NULL);
+    } else {
+        qapi_event_send_colo_exit(COLO_MODE_PRIMARY,
+                                  COLO_EXIT_REASON_REQUEST, NULL);
+    }
 
     if (s->rp_state.from_dst_file) {
         qemu_fclose(s->rp_state.from_dst_file);
@@ -520,6 +532,13 @@ out:
     if (local_err) {
         error_report_err(local_err);
     }
+    if (!failover_request_is_active()) {
+        qapi_event_send_colo_exit(COLO_MODE_SECONDARY,
+                                  COLO_EXIT_REASON_ERROR, NULL);
+    } else {
+        qapi_event_send_colo_exit(COLO_MODE_SECONDARY,
+                                  COLO_EXIT_REASON_REQUEST, NULL);
+    }
 
     if (fb) {
         qemu_fclose(fb);
diff --git a/qapi-schema.json b/qapi-schema.json
index ee7131d..d729b61 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -835,6 +835,20 @@
   'data': [ 'unknown', 'primary', 'secondary'] }
 
 ##
+# @COLOExitReason
+#
+# The reason for a COLO exit
+#
+# @request: COLO exit is due to an external request
+#
+# @error: COLO exit is due to an internal error
+#
+# Since: 2.8
+##
+{ 'enum': 'COLOExitReason',
+  'data': [ 'request', 'error' ] }
+
+##
 # @x-colo-lost-heartbeat
 #
 # Tell qemu that heartbeat is lost, request it to do takeover procedures.
diff --git a/qapi/event.json b/qapi/event.json
index 8642052..88d10e7 100644
--- a/qapi/event.json
+++ b/qapi/event.json
@@ -268,6 +268,21 @@
   'data': { 'pass': 'int' } }
 
 ##
+# @COLO_EXIT
+#
+# Emitted when VM finishes COLO mode due to some errors happening or
+# at the request of users.
+#
+# @mode: which COLO mode the VM was in when it exited.
+#
+# @reason: describes the reason for the COLO exit.
+#
+# Since: 2.8
+##
+{ 'event': 'COLO_EXIT',
+  'data': {'mode': 'COLOMode', 'reason': 'COLOExitReason' } }
+
+##
 # @ACPI_DEVICE_OST
 #
 # Emitted when guest executes ACPI _OST method.
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 21/34] COLO failover: Shutdown related socket fd when do failover

[zhanghailiang]

If the net connection between primary host and secondary host
is broken while COLO/COLO incoming thread is blocked in read()/write()
socket fd.
It will be a long time to detect this error until connection is timeout.

Here we shutdown all the related socket file descriptors to wake up the
blocking operation in failover BH. Besides, we should close the corresponding
file descriptors after failvoer BH shutdown them, or there will be an error.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v17:
- Rename colo_sem to colo_exit_sem.
v13:
- Add Reviewed-by tag
- Use semaphore to notify colo/colo incoming loop that
  failover work is finished.
v12:
- Shutdown both QEMUFile's fd though they may use the
  same fd. (Dave's suggestion)
v11:
- Only shutdown fd for once
---
 include/migration/migration.h |  3 +++
 migration/colo.c              | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/include/migration/migration.h b/include/migration/migration.h
index 8ae5248..15e01f3 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -113,6 +113,7 @@ struct MigrationIncomingState {
     QemuThread colo_incoming_thread;
     /* The coroutine we should enter (back) after failover */
     Coroutine *migration_incoming_co;
+    QemuSemaphore colo_incoming_sem;
 
     /* See savevm.c */
     LoadStateEntry_Head loadvm_handlers;
@@ -183,6 +184,8 @@ struct MigrationState
     QSIMPLEQ_HEAD(src_page_requests, MigrationSrcPageRequest) src_page_requests;
     /* The RAMBlock used in the last src_page_request */
     RAMBlock *last_req_rb;
+    /* The semaphore is used to notify COLO thread that failover is finished */
+    QemuSemaphore colo_exit_sem;
 
     /* The last error that occurred */
     Error *error;
diff --git a/migration/colo.c b/migration/colo.c
index f8fce0d..af1cf8e 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -60,6 +60,18 @@ static void secondary_vm_do_failover(void)
         /* recover runstate to normal migration finish state */
         autostart = true;
     }
+    /*
+     * Make sure COLO incoming thread not block in recv or send,
+     * If mis->from_src_file and mis->to_src_file use the same fd,
+     * The second shutdown() will return -1, we ignore this value,
+     * It is harmless.
+     */
+    if (mis->from_src_file) {
+        qemu_file_shutdown(mis->from_src_file);
+    }
+    if (mis->to_src_file) {
+        qemu_file_shutdown(mis->to_src_file);
+    }
 
     old_state = failover_set_state(FAILOVER_STATUS_HANDLING,
                                    FAILOVER_STATUS_COMPLETED);
@@ -68,6 +80,8 @@ static void secondary_vm_do_failover(void)
                      "secondary VM", old_state);
         return;
     }
+    /* Notify COLO incoming thread that failover work is finished */
+    qemu_sem_post(&mis->colo_incoming_sem);
     /* For Secondary VM, jump to incoming co */
     if (mis->migration_incoming_co) {
         qemu_coroutine_enter(mis->migration_incoming_co);
@@ -82,6 +96,18 @@ static void primary_vm_do_failover(void)
     migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
                       MIGRATION_STATUS_COMPLETED);
 
+    /*
+     * Wake up COLO thread which may blocked in recv() or send(),
+     * The s->rp_state.from_dst_file and s->to_dst_file may use the
+     * same fd, but we still shutdown the fd for twice, it is harmless.
+     */
+    if (s->to_dst_file) {
+        qemu_file_shutdown(s->to_dst_file);
+    }
+    if (s->rp_state.from_dst_file) {
+        qemu_file_shutdown(s->rp_state.from_dst_file);
+    }
+
     old_state = failover_set_state(FAILOVER_STATUS_HANDLING,
                                    FAILOVER_STATUS_COMPLETED);
     if (old_state != FAILOVER_STATUS_HANDLING) {
@@ -89,6 +115,8 @@ static void primary_vm_do_failover(void)
                      old_state);
         return;
     }
+    /* Notify COLO thread that failover work is finished */
+    qemu_sem_post(&s->colo_exit_sem);
 }
 
 void colo_do_failover(MigrationState *s)
@@ -374,6 +402,14 @@ out:
                                   COLO_EXIT_REASON_REQUEST, NULL);
     }
 
+    /* Hope this not to be too long to wait here */
+    qemu_sem_wait(&s->colo_exit_sem);
+    qemu_sem_destroy(&s->colo_exit_sem);
+    /*
+     * Must be called after failover BH is completed,
+     * Or the failover BH may shutdown the wrong fd that
+     * re-used by other threads after we release here.
+     */
     if (s->rp_state.from_dst_file) {
         qemu_fclose(s->rp_state.from_dst_file);
     }
@@ -382,6 +418,7 @@ out:
 void migrate_start_colo_process(MigrationState *s)
 {
     qemu_mutex_unlock_iothread();
+    qemu_sem_init(&s->colo_exit_sem, 0);
     migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
                       MIGRATION_STATUS_COLO);
     colo_process_checkpoint(s);
@@ -421,6 +458,8 @@ void *colo_process_incoming_thread(void *opaque)
     Error *local_err = NULL;
     int ret;
 
+    qemu_sem_init(&mis->colo_incoming_sem, 0);
+
     migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
                       MIGRATION_STATUS_COLO);
 
@@ -550,6 +589,10 @@ out:
      */
     colo_release_ram_cache();
 
+    /* Hope this not to be too long to loop here */
+    qemu_sem_wait(&mis->colo_incoming_sem);
+    qemu_sem_destroy(&mis->colo_incoming_sem);
+    /* Must be called after failover BH is completed */
     if (mis->to_src_file) {
         qemu_fclose(mis->to_src_file);
     }
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 22/34] COLO failover: Don't do failover during loading VM's state

[zhanghailiang]

We should not do failover work while the main thread is loading
VM's state. Otherwise it will destroy the consistent of VM's memory and
device state.

Here we add a new failover status 'RELAUNCH' which means we should
relaunch the process of failover.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v14:
- Move the place of 'vmstate_loading = false;'.
v13:
- Add Reviewed-by tag
---
 include/migration/failover.h |  2 ++
 migration/colo.c             | 25 +++++++++++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/include/migration/failover.h b/include/migration/failover.h
index c4bd81e..99b0d58 100644
--- a/include/migration/failover.h
+++ b/include/migration/failover.h
@@ -20,6 +20,8 @@ typedef enum COLOFailoverStatus {
     FAILOVER_STATUS_REQUEST = 1, /* Request but not handled */
     FAILOVER_STATUS_HANDLING = 2, /* In the process of handling failover */
     FAILOVER_STATUS_COMPLETED = 3, /* Finish the failover process */
+    /* Optional, Relaunch the failover process, again 'NONE' -> 'COMPLETED' */
+    FAILOVER_STATUS_RELAUNCH = 4,
 } COLOFailoverStatus;
 
 void failover_init_state(void);
diff --git a/migration/colo.c b/migration/colo.c
index af1cf8e..7bddb1f 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -21,6 +21,8 @@
 #include "migration/failover.h"
 #include "qapi-event.h"
 
+static bool vmstate_loading;
+
 #define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024)
 
 bool colo_supported(void)
@@ -52,6 +54,19 @@ static void secondary_vm_do_failover(void)
     int old_state;
     MigrationIncomingState *mis = migration_incoming_get_current();
 
+    /* Can not do failover during the process of VM's loading VMstate, Or
+     * it will break the secondary VM.
+     */
+    if (vmstate_loading) {
+        old_state = failover_set_state(FAILOVER_STATUS_HANDLING,
+                                       FAILOVER_STATUS_RELAUNCH);
+        if (old_state != FAILOVER_STATUS_HANDLING) {
+            error_report("Unknown error while do failover for secondary VM,"
+                         "old_state: %d", old_state);
+        }
+        return;
+    }
+
     migrate_set_state(&mis->state, MIGRATION_STATUS_COLO,
                       MIGRATION_STATUS_COMPLETED);
 
@@ -552,13 +567,22 @@ 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");
             qemu_mutex_unlock_iothread();
             goto out;
         }
+
+        vmstate_loading = false;
         qemu_mutex_unlock_iothread();
 
+        if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) {
+            failover_set_state(FAILOVER_STATUS_RELAUNCH, FAILOVER_STATUS_NONE);
+            failover_request_active(NULL);
+            goto out;
+        }
+
         colo_send_message(mis->to_src_file, COLO_MESSAGE_VMSTATE_LOADED,
                      &local_err);
         if (local_err) {
@@ -567,6 +591,7 @@ void *colo_process_incoming_thread(void *opaque)
     }
 
 out:
+    vmstate_loading = false;
     /* Throw the unreported error message after exited from loop */
     if (local_err) {
         error_report_err(local_err);
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 23/34] COLO: Process shutdown command for VM in COLO state

[zhanghailiang]

If VM is in COLO FT state, we should do some extra work before normal shutdown
process. SVM will ignore the shutdown command if this command is issued directly
to it. PVM will send the shutdown command to SVM if it gets this command.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v15:
- Go on the shutdown process even some error happened
  while sent 'SHUTDOWN' message to SVM.
- Add Reviewed-by tag
v14:
- Remove 'colo_shutdown' variable, use colo_shutdown_request directly
v13:
- Move COLO shutdown related codes to colo.c file (Dave's suggestion)
---
 include/migration/colo.h |  2 ++
 include/sysemu/sysemu.h  |  3 +++
 migration/colo.c         | 47 +++++++++++++++++++++++++++++++++++++++++++++--
 qapi-schema.json         |  4 +++-
 stubs/migration-colo.c   |  5 +++++
 vl.c                     | 19 ++++++++++++++++---
 6 files changed, 74 insertions(+), 6 deletions(-)

diff --git a/include/migration/colo.h b/include/migration/colo.h
index e32eef4..b16c642 100644
--- a/include/migration/colo.h
+++ b/include/migration/colo.h
@@ -35,4 +35,6 @@ COLOMode get_colo_mode(void);
 
 /* failover */
 void colo_do_failover(MigrationState *s);
+
+bool colo_handle_shutdown(void);
 #endif
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index ee7c760..1497c8b 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -51,6 +51,8 @@ typedef enum WakeupReason {
     QEMU_WAKEUP_REASON_OTHER,
 } WakeupReason;
 
+extern int colo_shutdown_requested;
+
 void qemu_system_reset_request(void);
 void qemu_system_suspend_request(void);
 void qemu_register_suspend_notifier(Notifier *notifier);
@@ -58,6 +60,7 @@ void qemu_system_wakeup_request(WakeupReason reason);
 void qemu_system_wakeup_enable(WakeupReason reason, bool enabled);
 void qemu_register_wakeup_notifier(Notifier *notifier);
 void qemu_system_shutdown_request(void);
+void qemu_system_shutdown_request_core(void);
 void qemu_system_powerdown_request(void);
 void qemu_register_powerdown_notifier(Notifier *notifier);
 void qemu_system_debug_request(void);
diff --git a/migration/colo.c b/migration/colo.c
index 7bddb1f..ef2bac4 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -328,6 +328,21 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
         goto out;
     }
 
+    if (colo_shutdown_requested) {
+        colo_send_message(s->to_dst_file, COLO_MESSAGE_GUEST_SHUTDOWN,
+                          &local_err);
+        if (local_err) {
+            error_free(local_err);
+            /* Go on the shutdown process and throw the error message */
+            error_report("Failed to send shutdown message to SVM");
+        }
+        qemu_fflush(s->to_dst_file);
+        colo_shutdown_requested = 0;
+        qemu_system_shutdown_request_core();
+        /* Fix me: Just let the colo thread exit ? */
+        qemu_thread_exit(0);
+    }
+
     ret = 0;
 
     qemu_mutex_lock_iothread();
@@ -383,8 +398,9 @@ static void colo_process_checkpoint(MigrationState *s)
         }
 
         current_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
-        if (current_time - checkpoint_time <
-            s->parameters.x_checkpoint_delay) {
+        if ((current_time - checkpoint_time <
+            s->parameters.x_checkpoint_delay) &&
+            !colo_shutdown_requested) {
             int64_t delay_ms;
 
             delay_ms = s->parameters.x_checkpoint_delay -
@@ -456,6 +472,16 @@ static void colo_wait_handle_message(QEMUFile *f, int *checkpoint_request,
     case COLO_MESSAGE_CHECKPOINT_REQUEST:
         *checkpoint_request = 1;
         break;
+    case COLO_MESSAGE_GUEST_SHUTDOWN:
+        qemu_mutex_lock_iothread();
+        vm_stop_force_state(RUN_STATE_COLO);
+        qemu_system_shutdown_request_core();
+        qemu_mutex_unlock_iothread();
+        /*
+         * The main thread will be exit and terminate the whole
+         * process, do need some cleanup ?
+         */
+        qemu_thread_exit(0);
     default:
         *checkpoint_request = 0;
         error_setg(errp, "Got unknown COLO message: %d", msg);
@@ -625,3 +651,20 @@ out:
 
     return NULL;
 }
+
+bool colo_handle_shutdown(void)
+{
+    /*
+     * If VM is in COLO-FT mode, we need do some significant work before
+     * respond to the shutdown request. Besides, Secondary VM will ignore
+     * the shutdown request from users.
+     */
+    if (migration_incoming_in_colo_state()) {
+        return true;
+    }
+    if (migration_in_colo_state()) {
+        colo_shutdown_requested = 1;
+        return true;
+    }
+    return false;
+}
diff --git a/qapi-schema.json b/qapi-schema.json
index d729b61..e5ea7b5 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -811,12 +811,14 @@
 #
 # @vmstate-loaded: VM's state has been loaded by SVM.
 #
+# @guest-shutdown: shutdown require from PVM to SVM
+#
 # Since: 2.8
 ##
 { 'enum': 'COLOMessage',
   'data': [ 'checkpoint-ready', 'checkpoint-request', 'checkpoint-reply',
             'vmstate-send', 'vmstate-size', 'vmstate-received',
-            'vmstate-loaded' ] }
+            'vmstate-loaded', 'guest-shutdown' ] }
 
 ##
 # @COLOMode
diff --git a/stubs/migration-colo.c b/stubs/migration-colo.c
index 7811764..167b191 100644
--- a/stubs/migration-colo.c
+++ b/stubs/migration-colo.c
@@ -44,3 +44,8 @@ void qmp_x_colo_lost_heartbeat(Error **errp)
                      " with --enable-colo option in order to support"
                      " COLO feature");
 }
+
+bool colo_handle_shutdown(void)
+{
+    return false;
+}
diff --git a/vl.c b/vl.c
index 62e8d41..8969b49 100644
--- a/vl.c
+++ b/vl.c
@@ -1620,6 +1620,8 @@ static NotifierList wakeup_notifiers =
     NOTIFIER_LIST_INITIALIZER(wakeup_notifiers);
 static uint32_t wakeup_reason_mask = ~(1 << QEMU_WAKEUP_REASON_NONE);
 
+int colo_shutdown_requested;
+
 int qemu_shutdown_requested_get(void)
 {
     return shutdown_requested;
@@ -1753,7 +1755,10 @@ void qemu_system_guest_panicked(void)
 void qemu_system_reset_request(void)
 {
     if (no_reboot) {
-        shutdown_requested = 1;
+        qemu_system_shutdown_request();
+        if (!shutdown_requested) {/* colo handle it ? */
+            return;
+        }
     } else {
         reset_requested = 1;
     }
@@ -1826,14 +1831,22 @@ void qemu_system_killed(int signal, pid_t pid)
     qemu_notify_event();
 }
 
-void qemu_system_shutdown_request(void)
+void qemu_system_shutdown_request_core(void)
 {
-    trace_qemu_system_shutdown_request();
     replay_shutdown_request();
     shutdown_requested = 1;
     qemu_notify_event();
 }
 
+void qemu_system_shutdown_request(void)
+{
+    trace_qemu_system_shutdown_request();
+    if (colo_handle_shutdown()) {
+        return;
+    }
+    qemu_system_shutdown_request_core();
+}
+
 static void qemu_system_powerdown(void)
 {
     qapi_event_send_powerdown(&error_abort);
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 24/34] COLO: Update the global runstate after going into colo state

[zhanghailiang]

If we start qemu with -S, the runstate will change from 'prelaunch' to 'running'
after going into colo state.
So it is necessary to update the global runstate after going into colo state.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v13:
- Add Reviewed-by tag
---
 migration/colo.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/migration/colo.c b/migration/colo.c
index ef2bac4..50693bb 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -391,6 +391,11 @@ static void colo_process_checkpoint(MigrationState *s)
     qemu_mutex_unlock_iothread();
     trace_colo_vm_state_change("stop", "run");
 
+    ret = global_state_store();
+    if (ret < 0) {
+        goto out;
+    }
+
     while (s->state == MIGRATION_STATUS_COLO) {
         if (failover_request_is_active()) {
             error_report("failover request");
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 25/34] savevm: Introduce two helper functions for save/find loadvm_handlers entry

[zhanghailiang]

For COLO's checkpoint process, we will do savevm/loadvm repeatedly.
So every time we call qemu_loadvm_section_start_full(), we will
add all sections information into loadvm_handlers list for one time.
There will be many instances in loadvm_handlers for one section,
and this will lead to memory leak.

We need to check if we have the section info in loadvm_handlers list
before save it. For normal migration, it is harmless.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v14:
- Add Reviewed-by tag
-
v13:
- New patch
---
 migration/savevm.c | 55 +++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 40 insertions(+), 15 deletions(-)

diff --git a/migration/savevm.c b/migration/savevm.c
index 33a2911..7c1edef 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1729,6 +1729,37 @@ void loadvm_free_handlers(MigrationIncomingState *mis)
     }
 }
 
+static LoadStateEntry *loadvm_save_section_entry(MigrationIncomingState *mis,
+                                                 SaveStateEntry *se,
+                                                 uint32_t section_id,
+                                                 uint32_t version_id)
+{
+    LoadStateEntry *le;
+
+    /* Add entry */
+    le = g_malloc0(sizeof(*le));
+
+    le->se = se;
+    le->section_id = section_id;
+    le->version_id = version_id;
+    QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
+    return le;
+}
+
+static LoadStateEntry *loadvm_find_section_entry(MigrationIncomingState *mis,
+                                                 uint32_t section_id)
+{
+    LoadStateEntry *le;
+
+    QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
+        if (le->section_id == section_id) {
+            break;
+        }
+    }
+
+    return le;
+}
+
 static int
 qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis)
 {
@@ -1771,15 +1802,12 @@ qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis)
         return -EINVAL;
     }
 
-    /* Add entry */
-    le = g_malloc0(sizeof(*le));
-
-    le->se = se;
-    le->section_id = section_id;
-    le->version_id = version_id;
-    QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
-
-    ret = vmstate_load(f, le->se, le->version_id);
+     /* Check if we have saved this section info before, if not, save it */
+    le = loadvm_find_section_entry(mis, section_id);
+    if (!le) {
+        le = loadvm_save_section_entry(mis, se, section_id, version_id);
+    }
+    ret = vmstate_load(f, se, version_id);
     if (ret < 0) {
         error_report("error while loading state for instance 0x%x of"
                      " device '%s'", instance_id, idstr);
@@ -1802,12 +1830,9 @@ qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis)
     section_id = qemu_get_be32(f);
 
     trace_qemu_loadvm_state_section_partend(section_id);
-    QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
-        if (le->section_id == section_id) {
-            break;
-        }
-    }
-    if (le == NULL) {
+
+    le = loadvm_find_section_entry(mis, section_id);
+    if (!le) {
         error_report("Unknown savevm section %d", section_id);
         return -EINVAL;
     }
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 26/34] migration/savevm: Add new helpers to process the different stages of loadvm

[zhanghailiang]

There are several stages during loadvm process. In different stage,
migration incoming processes different section.
We want to control these stages more accuracy, to optimize the COLO
capability.

Here we add two new helper functions: qemu_loadvm_state_begin()
and qemu_load_device_state().
Besides, we make qemu_loadvm_state_main() API public.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v16:
- Add Reviewed-by
v14:
- Split from patch 'COLO: Separate the process of saving/loading
  ram and device state
---
 include/sysemu/sysemu.h |  3 +++
 migration/savevm.c      | 38 +++++++++++++++++++++++++++++++++++---
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 1497c8b..9fe8224 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -134,6 +134,9 @@ void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
                                            uint64_t *length_list);
 
 int qemu_loadvm_state(QEMUFile *f);
+int qemu_loadvm_state_begin(QEMUFile *f);
+int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
+int qemu_load_device_state(QEMUFile *f);
 
 extern int autostart;
 
diff --git a/migration/savevm.c b/migration/savevm.c
index 7c1edef..390816a 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1246,8 +1246,6 @@ enum LoadVMExitCodes {
     LOADVM_QUIT     =  1,
 };
 
-static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
-
 /* ------ incoming postcopy messages ------ */
 /* 'advise' arrives before any transfers just to tell us that a postcopy
  * *might* happen - it might be skipped if precopy transferred everything
@@ -1850,7 +1848,7 @@ qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis)
     return 0;
 }
 
-static int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
+int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
 {
     uint8_t section_type;
     int ret;
@@ -1983,6 +1981,40 @@ int qemu_loadvm_state(QEMUFile *f)
     return ret;
 }
 
+int qemu_loadvm_state_begin(QEMUFile *f)
+{
+    MigrationIncomingState *mis = migration_incoming_get_current();
+    Error *local_err = NULL;
+    int ret;
+
+    if (qemu_savevm_state_blocked(&local_err)) {
+        error_report_err(local_err);
+        return -EINVAL;
+    }
+    /* Load QEMU_VM_SECTION_START section */
+    ret = qemu_loadvm_state_main(f, mis);
+    if (ret < 0) {
+        error_report("Failed to loadvm begin work: %d", ret);
+    }
+    return ret;
+}
+
+int qemu_load_device_state(QEMUFile *f)
+{
+    MigrationIncomingState *mis = migration_incoming_get_current();
+    int ret;
+
+    /* Load QEMU_VM_SECTION_FULL section */
+    ret = qemu_loadvm_state_main(f, mis);
+    if (ret < 0) {
+        error_report("Failed to load device state: %d", ret);
+        return ret;
+    }
+
+    cpu_synchronize_all_post_init();
+    return 0;
+}
+
 void hmp_savevm(Monitor *mon, const QDict *qdict)
 {
     BlockDriverState *bs, *bs1;
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 27/34] migration/savevm: Export two helper functions for savevm process

[zhanghailiang]

We add a new helper functions qemu_savevm_live_state(),
and make qemu_save_device_state() public.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v15:
- Add Reviewd-by tag
v14:
- New patch split from previous
 'COLO: Separate the process of saving/loading ram and device state
---
 include/sysemu/sysemu.h |  3 +++
 migration/savevm.c      | 16 ++++++++++++----
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 9fe8224..ac2ed76 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -133,6 +133,9 @@ void qemu_savevm_send_postcopy_ram_discard(QEMUFile *f, const char *name,
                                            uint64_t *start_list,
                                            uint64_t *length_list);
 
+void qemu_savevm_live_state(QEMUFile *f);
+int qemu_save_device_state(QEMUFile *f);
+
 int qemu_loadvm_state(QEMUFile *f);
 int qemu_loadvm_state_begin(QEMUFile *f);
 int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
diff --git a/migration/savevm.c b/migration/savevm.c
index 390816a..9085338 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -54,6 +54,7 @@
 #include "qemu/cutils.h"
 #include "io/channel-buffer.h"
 #include "io/channel-file.h"
+#include "migration/colo.h"
 
 #ifndef ETH_P_RARP
 #define ETH_P_RARP 0x8035
@@ -1189,13 +1190,20 @@ done:
     return ret;
 }
 
-static int qemu_save_device_state(QEMUFile *f)
+void qemu_savevm_live_state(QEMUFile *f)
 {
-    SaveStateEntry *se;
+    /* save QEMU_VM_SECTION_END section */
+    qemu_savevm_state_complete_precopy(f, true);
+    qemu_put_byte(f, QEMU_VM_EOF);
+}
 
-    qemu_put_be32(f, QEMU_VM_FILE_MAGIC);
-    qemu_put_be32(f, QEMU_VM_FILE_VERSION);
+int qemu_save_device_state(QEMUFile *f)
+{
+    SaveStateEntry *se;
 
+    if (!migration_in_colo_state()) {
+        qemu_savevm_state_header(f);
+    }
     cpu_synchronize_all_states();
 
     QTAILQ_FOREACH(se, &savevm_state.handlers, entry) {
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 28/34] COLO: Separate the process of saving/loading ram and device state

[zhanghailiang]

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 primary side to secondary side without
using channel-buffer as assistant, which also reduce the size of extra memory
was used during checkpoint.

Besides, we move the colo_flush_ram_cache to the proper position after the
above change.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v16:
- Add Reviewd-by tag
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   | 49 +++++++++++++++++++++++++++++++++++++++----------
 migration/ram.c    |  5 -----
 migration/savevm.c |  4 ++++
 3 files changed, 43 insertions(+), 15 deletions(-)

diff --git a/migration/colo.c b/migration/colo.c
index 50693bb..48cdf06 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -284,21 +284,37 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
         goto out;
     }
 
+    colo_send_message(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(fb);
-    qemu_savevm_state_begin(fb, &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(fb, 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(fb);
     qemu_mutex_unlock_iothread();
-
-    qemu_fflush(fb);
-
-    colo_send_message(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(fb);
+
     /*
      * We need the size of the VMstate data in Secondary side,
      * With which we can decide how much data should be read.
@@ -565,6 +581,17 @@ 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;
+        }
+
         value = colo_receive_message_value(mis->from_src_file,
                                  COLO_MESSAGE_VMSTATE_SIZE, &local_err);
         if (local_err) {
@@ -599,8 +626,10 @@ 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 198dc53..0507846 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2499,7 +2499,6 @@ 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++;
 
@@ -2534,7 +2533,6 @@ 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);
             }
@@ -2629,9 +2627,6 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
     wait_for_decompress_done();
     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 9085338..2d7a7ae 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -912,6 +912,10 @@ 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

[Qemu-devel] [PATCH COLO-Frame v18 29/34] COLO: Split qemu_savevm_state_begin out of checkpoint process

[zhanghailiang]

It is unnecessary to call qemu_savevm_state_begin() in every checkpoint process.
It mainly sets up devices and does the first device state pass. These data will
not change during the later checkpoint process. So, we split it out of
colo_do_checkpoint_transaction(), in this way, we can reduce these data
transferring in the subsequent checkpoint.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
v13:
- Fix some minor issues found by Dave
- Add Reviewed-by tag
---
 migration/colo.c | 51 ++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 36 insertions(+), 15 deletions(-)

diff --git a/migration/colo.c b/migration/colo.c
index 48cdf06..f618ca6 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -289,16 +289,6 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
         goto out;
     }
 
-    /* Disable block migration */
-    s->params.blk = 0;
-    s->params.shared = 0;
-    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();
     /*
      * Only save VM's live state, which not including device state.
@@ -373,6 +363,21 @@ out:
     return ret;
 }
 
+static int colo_prepare_before_save(MigrationState *s)
+{
+    int ret;
+
+    /* Disable block migration */
+    s->params.blk = 0;
+    s->params.shared = 0;
+    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");
+    }
+    return ret;
+}
+
 static void colo_process_checkpoint(MigrationState *s)
 {
     QIOChannelBuffer *bioc;
@@ -389,6 +394,11 @@ static void colo_process_checkpoint(MigrationState *s)
         goto out;
     }
 
+    ret = colo_prepare_before_save(s);
+    if (ret < 0) {
+        goto out;
+    }
+
     /*
      * Wait for Secondary finish loading VM states and enter COLO
      * restore.
@@ -510,6 +520,17 @@ static void colo_wait_handle_message(QEMUFile *f, int *checkpoint_request,
     }
 }
 
+static int colo_prepare_before_load(QEMUFile *f)
+{
+    int ret;
+
+    ret = qemu_loadvm_state_begin(f);
+    if (ret < 0) {
+        error_report("Load VM state begin error, ret=%d", ret);
+    }
+    return ret;
+}
+
 void *colo_process_incoming_thread(void *opaque)
 {
     MigrationIncomingState *mis = opaque;
@@ -549,6 +570,11 @@ void *colo_process_incoming_thread(void *opaque)
     fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc));
     object_unref(OBJECT(bioc));
 
+    ret = colo_prepare_before_load(mis->from_src_file);
+    if (ret < 0) {
+        goto out;
+    }
+
     colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
                       &local_err);
     if (local_err) {
@@ -581,11 +607,6 @@ 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");
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 30/34] filter-buffer: Accept zero interval

[zhanghailiang]

We may want to accept zero interval when VM FT solutions like MC
or COLO use this filter to release packets on demand.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Yang Hongyang <hongyang.yang@easystack.cn>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Yang Hongyang <hongyang.yang@easystack.cn>
---
 net/filter-buffer.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/net/filter-buffer.c b/net/filter-buffer.c
index cc6bd94..346306a 100644
--- a/net/filter-buffer.c
+++ b/net/filter-buffer.c
@@ -118,16 +118,6 @@ static void filter_buffer_setup(NetFilterState *nf, Error **errp)
 {
     FilterBufferState *s = FILTER_BUFFER(nf);
 
-    /*
-     * We may want to accept zero interval when VM FT solutions like MC
-     * or COLO use this filter to release packets on demand.
-     */
-    if (!s->interval) {
-        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "interval",
-                   "a non-zero interval");
-        return;
-    }
-
     s->incoming_queue = qemu_new_net_queue(qemu_netfilter_pass_to_next, nf);
     filter_buffer_setup_timer(nf);
 }
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 31/34] net: Add notifier/callback for netdev init

[zhanghailiang]

We can register some callback for this notifier,
this will be used by COLO to register a callback which
will add each netdev a buffer filter.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Yang Hongyang <hongyang.yang@easystack.cn>
---
v17:
- Rename netdev_init_add_notifier() to netdev_register_init_notifier()
v16:
- Simplify the codes by using some helpers in QEMU
v14:
- New patch
---
 include/net/net.h |  3 +++
 net/net.c         | 12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/include/net/net.h b/include/net/net.h
index e8d9e9e..b67fe20 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -8,6 +8,7 @@
 #include "net/queue.h"
 #include "migration/vmstate.h"
 #include "qapi-types.h"
+#include "qemu/notify.h"
 
 #define MAC_FMT "%02X:%02X:%02X:%02X:%02X:%02X"
 #define MAC_ARG(x) ((uint8_t *)(x))[0], ((uint8_t *)(x))[1], \
@@ -195,6 +196,8 @@ struct NICInfo {
     int nvectors;
 };
 
+void netdev_register_init_notifier(Notifier *notify);
+
 extern int nb_nics;
 extern NICInfo nd_table[MAX_NICS];
 extern const char *host_net_devices[];
diff --git a/net/net.c b/net/net.c
index c124b11..4e8268d 100644
--- a/net/net.c
+++ b/net/net.c
@@ -56,6 +56,9 @@
 static VMChangeStateEntry *net_change_state_entry;
 static QTAILQ_HEAD(, NetClientState) net_clients;
 
+static NotifierList netdev_init_notifiers =
+    NOTIFIER_LIST_INITIALIZER(netdev_init_notifiers);
+
 const char *host_net_devices[] = {
     "tap",
     "socket",
@@ -929,6 +932,10 @@ static int net_init_nic(const Netdev *netdev, const char *name,
     return idx;
 }
 
+void netdev_register_init_notifier(Notifier *notify)
+{
+    notifier_list_add(&netdev_init_notifiers, notify);
+}
 
 static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
     const Netdev *netdev,
@@ -1056,6 +1063,11 @@ static int net_client_init1(const void *object, bool is_netdev, Error **errp)
         }
         return -1;
     }
+    if (is_netdev) {
+        const Netdev *netdev = object;
+
+        notifier_list_notify(&netdev_init_notifiers, netdev->id);
+    }
     return 0;
 }
 
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 32/34] COLO/filter: Add each netdev a buffer filter

[zhanghailiang]

For COLO periodic mode, it needs to buffer packets that
sent by VM, and we will not release these packets until
finish a checkpoint.

Here, we add each netdev a buffer-filter that will be controlled
by COLO. It is off by default, and the packets will not pass
through these filters. If users don't enable COLO while configure
qemu, these buffer-filters will not be added.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Yang Hongyang <hongyang.yang@easystack.cn>
---
v16:
- Remove the useless check in colo_add_buffer_filter()
v15:
- call object_new_with_props() directly to add filter in
  colo_add_buffer_filter. (Jason's suggestion)
v14:
- New patch
---
 include/migration/colo.h |  3 +++
 include/net/filter.h     |  2 ++
 migration/colo-comm.c    |  7 +++++++
 migration/colo.c         | 39 +++++++++++++++++++++++++++++++++++++++
 net/filter-buffer.c      |  2 --
 stubs/migration-colo.c   |  4 ++++
 6 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/include/migration/colo.h b/include/migration/colo.h
index b16c642..b08715a 100644
--- a/include/migration/colo.h
+++ b/include/migration/colo.h
@@ -37,4 +37,7 @@ COLOMode get_colo_mode(void);
 void colo_do_failover(MigrationState *s);
 
 bool colo_handle_shutdown(void);
+bool colo_shutdown(void);
+void colo_add_buffer_filter(Notifier *notifier, void *data);
+
 #endif
diff --git a/include/net/filter.h b/include/net/filter.h
index 0c4a2ea..817eaf4 100644
--- a/include/net/filter.h
+++ b/include/net/filter.h
@@ -21,6 +21,8 @@
 #define NETFILTER_CLASS(klass) \
     OBJECT_CLASS_CHECK(NetFilterClass, (klass), TYPE_NETFILTER)
 
+#define TYPE_FILTER_BUFFER "filter-buffer"
+
 typedef void (FilterSetup) (NetFilterState *nf, Error **errp);
 typedef void (FilterCleanup) (NetFilterState *nf);
 /*
diff --git a/migration/colo-comm.c b/migration/colo-comm.c
index 716a4f7..44ac76a 100644
--- a/migration/colo-comm.c
+++ b/migration/colo-comm.c
@@ -14,12 +14,14 @@
 #include "qemu/osdep.h"
 #include <migration/colo.h>
 #include "trace.h"
+#include <net/net.h>
 
 typedef struct {
      bool colo_requested;
 } COLOInfo;
 
 static COLOInfo colo_info;
+static Notifier netdev_init_notifier;
 
 COLOMode get_colo_mode(void)
 {
@@ -59,6 +61,11 @@ static const VMStateDescription colo_state = {
 void colo_info_init(void)
 {
     vmstate_register(NULL, 0, &colo_state, &colo_info);
+    /* FIXME: Remove this after COLO switch to using colo-proxy */
+    if (colo_supported()) {
+        netdev_init_notifier.notify = colo_add_buffer_filter;
+        netdev_register_init_notifier(&netdev_init_notifier);
+    }
 }
 
 bool migration_incoming_enable_colo(void)
diff --git a/migration/colo.c b/migration/colo.c
index f618ca6..9af48da 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -20,11 +20,22 @@
 #include "qapi/error.h"
 #include "migration/failover.h"
 #include "qapi-event.h"
+#include "net/net.h"
+#include "net/filter.h"
+#include "net/vhost_net.h"
 
 static bool vmstate_loading;
 
 #define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024)
 
+typedef struct COLOListNode {
+    void *opaque;
+    QLIST_ENTRY(COLOListNode) node;
+} COLOListNode;
+
+static QLIST_HEAD(, COLOListNode) COLOBufferFilters =
+    QLIST_HEAD_INITIALIZER(COLOBufferFilters);
+
 bool colo_supported(void)
 {
     return true;
@@ -378,6 +389,34 @@ static int colo_prepare_before_save(MigrationState *s)
     return ret;
 }
 
+void colo_add_buffer_filter(Notifier *notifier, void *data)
+{
+    char *netdev_id = data;
+    NetFilterState *nf;
+    char filter_name[128];
+    Object *filter;
+    COLOListNode *filternode;
+
+    snprintf(filter_name, sizeof(filter_name),
+            "%scolo", netdev_id);
+
+    filter = object_new_with_props(TYPE_FILTER_BUFFER,
+                        object_get_objects_root(),
+                        filter_name, NULL,
+                        "netdev", netdev_id,
+                        "status", "off",
+                        NULL);
+    if (!filter) {
+        return;
+    }
+    nf =  NETFILTER(filter);
+    /* Only buffer the packets that sent out by VM */
+    nf->direction = NET_FILTER_DIRECTION_RX;
+    filternode = g_new0(COLOListNode, 1);
+    filternode->opaque = nf;
+    QLIST_INSERT_HEAD(&COLOBufferFilters, filternode, node);
+}
+
 static void colo_process_checkpoint(MigrationState *s)
 {
     QIOChannelBuffer *bioc;
diff --git a/net/filter-buffer.c b/net/filter-buffer.c
index 346306a..d1cf595 100644
--- a/net/filter-buffer.c
+++ b/net/filter-buffer.c
@@ -17,8 +17,6 @@
 #include "qapi-visit.h"
 #include "qom/object.h"
 
-#define TYPE_FILTER_BUFFER "filter-buffer"
-
 #define FILTER_BUFFER(obj) \
     OBJECT_CHECK(FilterBufferState, (obj), TYPE_FILTER_BUFFER)
 
diff --git a/stubs/migration-colo.c b/stubs/migration-colo.c
index 167b191..ae29d47 100644
--- a/stubs/migration-colo.c
+++ b/stubs/migration-colo.c
@@ -49,3 +49,7 @@ bool colo_handle_shutdown(void)
 {
     return false;
 }
+
+void colo_add_buffer_filter(Notifier *notifier, void *data)
+{
+}
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 33/34] COLO: Control the status of buffer filters for PVM

[zhanghailiang]

Enable all buffer filters that added by COLO while
go into COLO process, and disable them while exit COLO.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Yang Hongyang <hongyang.yang@easystack.cn>
---
v16:
- Stop buffer filter while doing checkpoint and resume it after
  checkpoint.
v15:
- Re-implement colo_set_filter_status() based on COLOBufferFilters list.
- Fix the title of this patch
---
 migration/colo.c | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/migration/colo.c b/migration/colo.c
index 9af48da..ac16d61 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -114,10 +114,22 @@ static void secondary_vm_do_failover(void)
     }
 }
 
+static void colo_set_filter_status(const char *status, Error **errp)
+{
+    struct COLOListNode *e, *next;
+    NetFilterState *nf;
+
+    QLIST_FOREACH_SAFE(e, &COLOBufferFilters, node, next) {
+        nf = e->opaque;
+        object_property_set_str(OBJECT(nf), status, "status", errp);
+    }
+}
+
 static void primary_vm_do_failover(void)
 {
     MigrationState *s = migrate_get_current();
     int old_state;
+    Error *local_err = NULL;
 
     migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
                       MIGRATION_STATUS_COMPLETED);
@@ -141,6 +153,12 @@ static void primary_vm_do_failover(void)
                      old_state);
         return;
     }
+
+    colo_set_filter_status("off", &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+
     /* Notify COLO thread that failover work is finished */
     qemu_sem_post(&s->colo_exit_sem);
 }
@@ -294,7 +312,11 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     if (failover_request_is_active()) {
         goto out;
     }
-
+    /* Stop buffer filter and flush the buffered packets */
+    colo_set_filter_status("off", &local_err);
+    if (local_err) {
+        goto out;
+    }
     colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err);
     if (local_err) {
         goto out;
@@ -360,6 +382,10 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
         qemu_thread_exit(0);
     }
 
+    colo_set_filter_status("on", &local_err);
+    if (local_err) {
+        goto out;
+    }
     ret = 0;
 
     qemu_mutex_lock_iothread();
@@ -427,6 +453,11 @@ static void colo_process_checkpoint(MigrationState *s)
 
     failover_init_state();
 
+    colo_set_filter_status("on", &local_err);
+    if (local_err) {
+        goto out;
+    }
+
     s->rp_state.from_dst_file = qemu_file_get_return_path(s->to_dst_file);
     if (!s->rp_state.from_dst_file) {
         error_report("Open QEMUFile from_dst_file failed");
-- 
1.8.3.1

[Qemu-devel] [PATCH COLO-Frame v18 34/34] COLO: Add block replication into colo process

[zhanghailiang]

Make sure master start block replication after slave's block
replication started.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
---
 migration/colo.c      | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 migration/migration.c |  6 +++++-
 2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/migration/colo.c b/migration/colo.c
index ac16d61..52eb403 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -23,6 +23,8 @@
 #include "net/net.h"
 #include "net/filter.h"
 #include "net/vhost_net.h"
+#include "block/block.h"
+#include "replication.h"
 
 static bool vmstate_loading;
 
@@ -64,6 +66,7 @@ static void secondary_vm_do_failover(void)
 {
     int old_state;
     MigrationIncomingState *mis = migration_incoming_get_current();
+    Error *local_err = NULL;
 
     /* Can not do failover during the process of VM's loading VMstate, Or
      * it will break the secondary VM.
@@ -81,6 +84,11 @@ static void secondary_vm_do_failover(void)
     migrate_set_state(&mis->state, MIGRATION_STATUS_COLO,
                       MIGRATION_STATUS_COMPLETED);
 
+    replication_stop_all(true, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+
     if (!autostart) {
         error_report("\"-S\" qemu option will be ignored in secondary side");
         /* recover runstate to normal migration finish state */
@@ -159,6 +167,11 @@ static void primary_vm_do_failover(void)
         error_report_err(local_err);
     }
 
+    replication_stop_all(true, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+
     /* Notify COLO thread that failover work is finished */
     qemu_sem_post(&s->colo_exit_sem);
 }
@@ -317,6 +330,15 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     if (local_err) {
         goto out;
     }
+
+    /* We call this API although this may do nothing on primary side. */
+    qemu_mutex_lock_iothread();
+    replication_do_checkpoint_all(&local_err);
+    qemu_mutex_unlock_iothread();
+    if (local_err) {
+        goto out;
+    }
+
     colo_send_message(s->to_dst_file, COLO_MESSAGE_VMSTATE_SEND, &local_err);
     if (local_err) {
         goto out;
@@ -483,6 +505,12 @@ static void colo_process_checkpoint(MigrationState *s)
     object_unref(OBJECT(bioc));
 
     qemu_mutex_lock_iothread();
+    replication_start_all(REPLICATION_MODE_PRIMARY, &local_err);
+    if (local_err) {
+        qemu_mutex_unlock_iothread();
+        goto out;
+    }
+
     vm_start();
     qemu_mutex_unlock_iothread();
     trace_colo_vm_state_change("stop", "run");
@@ -576,6 +604,7 @@ static void colo_wait_handle_message(QEMUFile *f, int *checkpoint_request,
     case COLO_MESSAGE_GUEST_SHUTDOWN:
         qemu_mutex_lock_iothread();
         vm_stop_force_state(RUN_STATE_COLO);
+        replication_stop_all(false, NULL);
         qemu_system_shutdown_request_core();
         qemu_mutex_unlock_iothread();
         /*
@@ -645,6 +674,14 @@ void *colo_process_incoming_thread(void *opaque)
         goto out;
     }
 
+    qemu_mutex_lock_iothread();
+    bdrv_invalidate_cache_all(&local_err);
+    replication_start_all(REPLICATION_MODE_SECONDARY, &local_err);
+    qemu_mutex_unlock_iothread();
+    if (local_err) {
+        goto out;
+    }
+
     colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
                       &local_err);
     if (local_err) {
@@ -725,6 +762,18 @@ void *colo_process_incoming_thread(void *opaque)
             goto out;
         }
 
+        replication_get_error_all(&local_err);
+        if (local_err) {
+            qemu_mutex_unlock_iothread();
+            goto out;
+        }
+        /* discard colo disk buffer */
+        replication_do_checkpoint_all(&local_err);
+        if (local_err) {
+            qemu_mutex_unlock_iothread();
+            goto out;
+        }
+
         vmstate_loading = false;
         qemu_mutex_unlock_iothread();
 
diff --git a/migration/migration.c b/migration/migration.c
index 3358980..5b5971f 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1679,7 +1679,11 @@ static void migration_completion(MigrationState *s, int current_active_state,
 
         if (!ret) {
             ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
-            if (ret >= 0) {
+            /*
+             * Don't mark the image with BDRV_O_INACTIVE flag if
+             * we will go into COLO stage later.
+             */
+            if (ret >= 0 && !migrate_colo_enabled()) {
                 ret = bdrv_inactivate_all();
             }
             if (ret >= 0) {
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH COLO-Frame v18 00/34] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service (FT)

[Changlong Xie]

On 08/03/2016 08:25 PM, zhanghailiang wrote:
> It is based on '[PATCH v24 00/12] Block replication for continuous checkpoints' series.
> The complete codes can be found from the link:
> https://github.com/coloft/qemu/commits/colo-v3.1-periodic-mode

404 NOT FOUND. Would you like to upload it again :)

Thanks
	-Xie

Re: [Qemu-devel] [PATCH COLO-Frame v18 00/34] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service (FT)

[Hailiang Zhang]

On 2016/8/16 8:00, Changlong Xie wrote:
> On 08/03/2016 08:25 PM, zhanghailiang wrote:
>> It is based on '[PATCH v24 00/12] Block replication for continuous checkpoints' series.
>> The complete codes can be found from the link:
>> https://github.com/coloft/qemu/commits/colo-v3.1-periodic-mode
>
> 404 NOT FOUND. Would you like to upload it again :)
>
> Thanks
> 	-Xie
>

Sorry, i forgot update it, i have uploaded the new version now.

Thanks.

>
>
> .
>

Re: [Qemu-devel] [PATCH COLO-Frame v18 00/34] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service (FT)

[Changlong Xie]

On 08/17/2016 12:05 PM, Zhi Yong Wu wrote:
> HI
>
> Can you update http://wiki.qemu.org/Features/COLO and
> block-replication.txt? Recently i had a try, but failed. By the way,

I will update both of them later.

> QEMU was built based on
> https://github.com/coloft/qemu/commits/colo-v3.1-periodic-mode.
>

BTW, you should send email to QEMU community directly, but not personal 
email next time.

Thanks
	-Xie

>
> Regards,
>
> Zhi Yong Wu
>
> On Wed, Aug 3, 2016 at 8:25 PM, zhanghailiang
> <zhang.zhanghailiang@huawei.com> wrote:
>> This is the 18th version of COLO FT feature.
>>
>> It is based on '[PATCH v24 00/12] Block replication for continuous checkpoints' series.
>> The complete codes can be found from the link:
>> https://github.com/coloft/qemu/commits/colo-v3.1-periodic-mode
>>
>> For block part, Stefan promised to merge it.
>> So we would like to update this series to the latest upstream.
>>
>> For this series, only patch 32 ~ 34 are not reviewed, so
>> please help review them. Thanks.
>>
>> Cc: Stefan Hajnoczi <stefanha@redhat.com>
>> Cc: Jason Wang <jasowang@redhat.com>
>>
>> TODO:
>> 1. Checkpoint based on proxy in qemu
>> 2. The capability of continuous FT
>> 3. Optimize the VM's downtime during checkpoint
>>
>> zhanghailiang (34):
>>    configure: Add parameter for configure to enable/disable COLO support
>>    migration: Introduce capability 'x-colo' to migration
>>    COLO: migrate colo related info to secondary node
>>    migration: Integrate COLO checkpoint process into migration
>>    migration: Integrate COLO checkpoint process into loadvm
>>    COLO/migration: Create a new communication path from destination to
>>      source
>>    COLO: Implement COLO checkpoint protocol
>>    COLO: Add a new RunState RUN_STATE_COLO
>>    COLO: Save PVM state to secondary side when do checkpoint
>>    COLO: Load PVM's dirty pages into SVM's RAM cache temporarily
>>    ram/COLO: Record the dirty pages that SVM received
>>    COLO: Load VMState into buffer before restore it
>>    COLO: Flush PVM's cached RAM into SVM's memory
>>    COLO: Add checkpoint-delay parameter for migrate-set-parameters
>>    COLO: Synchronize PVM's state to SVM periodically
>>    COLO failover: Introduce a new command to trigger a failover
>>    COLO failover: Introduce state to record failover process
>>    COLO: Implement failover work for Primary VM
>>    COLO: Implement failover work for Secondary VM
>>    qmp event: Add COLO_EXIT event to notify users while exited from COLO
>>    COLO failover: Shutdown related socket fd when do failover
>>    COLO failover: Don't do failover during loading VM's state
>>    COLO: Process shutdown command for VM in COLO state
>>    COLO: Update the global runstate after going into colo state
>>    savevm: Introduce two helper functions for save/find loadvm_handlers
>>      entry
>>    migration/savevm: Add new helpers to process the different stages of
>>      loadvm
>>    migration/savevm: Export two helper functions for savevm process
>>    COLO: Separate the process of saving/loading ram and device state
>>    COLO: Split qemu_savevm_state_begin out of checkpoint process
>>    filter-buffer: Accept zero interval
>>    net: Add notifier/callback for netdev init
>>    COLO/filter: Add each netdev a buffer filter
>>    COLO: Control the status of buffer filters for PVM
>>    COLO: Add block replication into colo process
>>
>>   configure                     |  11 +
>>   docs/qmp-events.txt           |  16 +
>>   hmp-commands.hx               |  15 +
>>   hmp.c                         |  15 +
>>   hmp.h                         |   1 +
>>   include/exec/ram_addr.h       |   1 +
>>   include/migration/colo.h      |  43 +++
>>   include/migration/failover.h  |  33 ++
>>   include/migration/migration.h |  16 +
>>   include/net/filter.h          |   2 +
>>   include/net/net.h             |   3 +
>>   include/sysemu/sysemu.h       |   9 +
>>   migration/Makefile.objs       |   2 +
>>   migration/colo-comm.c         |  79 ++++
>>   migration/colo-failover.c     |  84 +++++
>>   migration/colo.c              | 844 ++++++++++++++++++++++++++++++++++++++++++
>>   migration/migration.c         |  84 ++++-
>>   migration/ram.c               | 175 ++++++++-
>>   migration/savevm.c            | 113 ++++--
>>   migration/trace-events        |   8 +
>>   net/filter-buffer.c           |  12 -
>>   net/net.c                     |  12 +
>>   qapi-schema.json              | 102 ++++-
>>   qapi/event.json               |  15 +
>>   qmp-commands.hx               |  24 +-
>>   stubs/Makefile.objs           |   1 +
>>   stubs/migration-colo.c        |  55 +++
>>   vl.c                          |  30 +-
>>   28 files changed, 1744 insertions(+), 61 deletions(-)
>>   create mode 100644 include/migration/colo.h
>>   create mode 100644 include/migration/failover.h
>>   create mode 100644 migration/colo-comm.c
>>   create mode 100644 migration/colo-failover.c
>>   create mode 100644 migration/colo.c
>>   create mode 100644 stubs/migration-colo.c
>>
>> --
>> 1.8.3.1
>>
>>
>>
>
>
>

Re: [Qemu-devel] [PATCH COLO-Frame v18 00/34] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service (FT)

[Amit Shah]

On (Wed) 03 Aug 2016 [20:25:38], zhanghailiang wrote:
> This is the 18th version of COLO FT feature.
> 
> It is based on '[PATCH v24 00/12] Block replication for continuous checkpoints' series.
> The complete codes can be found from the link:
> https://github.com/coloft/qemu/commits/colo-v3.1-periodic-mode
> 
> For block part, Stefan promised to merge it.
> So we would like to update this series to the latest upstream.
> 
> For this series, only patch 32 ~ 34 are not reviewed, so
> please help review them. Thanks.
> 
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> 
> TODO:
> 1. Checkpoint based on proxy in qemu
> 2. The capability of continuous FT
> 3. Optimize the VM's downtime during checkpoint

[...]

>  configure                     |  11 +
>  docs/qmp-events.txt           |  16 +

Can you add documentation into docs/migration.txt or into a new file,
and reference that from the migration.txt file?

Also, please fill out the new feature page based on this template:

http://qemu-project.org/NewFeatureTemplate

Thanks,

Re: [Qemu-devel] [PATCH COLO-Frame v18 00/34] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service (FT)

[Hailiang Zhang]

On 2016/8/26 5:52, Amit Shah wrote:
> On (Wed) 03 Aug 2016 [20:25:38], zhanghailiang wrote:
>> This is the 18th version of COLO FT feature.
>>
>> It is based on '[PATCH v24 00/12] Block replication for continuous checkpoints' series.
>> The complete codes can be found from the link:
>> https://github.com/coloft/qemu/commits/colo-v3.1-periodic-mode
>>
>> For block part, Stefan promised to merge it.
>> So we would like to update this series to the latest upstream.
>>
>> For this series, only patch 32 ~ 34 are not reviewed, so
>> please help review them. Thanks.
>>
>> Cc: Stefan Hajnoczi <stefanha@redhat.com>
>> Cc: Jason Wang <jasowang@redhat.com>
>>
>> TODO:
>> 1. Checkpoint based on proxy in qemu
>> 2. The capability of continuous FT
>> 3. Optimize the VM's downtime during checkpoint
>
> [...]
>
>>   configure                     |  11 +
>>   docs/qmp-events.txt           |  16 +
>
> Can you add documentation into docs/migration.txt or into a new file,
> and reference that from the migration.txt file?
>

OK, I have add the related documentation (docs/COLO-FT.txt) in the new version.

> Also, please fill out the new feature page based on this template:
>
> http://qemu-project.org/NewFeatureTemplate
>

I updated the feature description on http://wiki.qemu.org/Features/COLO.

Thanks :)
Hailiang

> Thanks,
>
> .
>