[Qemu-devel] [PATCH for-2.9 V3 0/3] Add new qmp commands to suppurt Xen COLO

[Qemu-devel] [PATCH for-2.9 V3 0/3] Add new qmp commands to suppurt Xen COLO

[Zhang Chen]

Xen COLO depend on qemu COLO replication function.
So, We need new qmp commands for Xen to use qemu replication.

Corresponding libxl patches already in xen.git.
Commit ID:

ed37ef1f91c20f0ab162ce60f8c38400b917fa64
COLO: introduce new API to prepare/start/do/get_error/stop replication

a0ddc0b359375b2418213966dfbdbfab593ecc6f
tools/libxl: introduction of libxl__qmp_restore to load qemu state


Zhang Chen (3):
  Migration: Don't load vmdesc when xen is enabled
  Add a new qmp command to start/stop replication
  Add a new qmp command to do checkpoint, get replication error

 docs/qmp-commands.txt | 42 ++++++++++++++++++++++++++++++++++++++++++
 migration/colo.c      | 33 +++++++++++++++++++++++++++++++++
 migration/savevm.c    |  4 ++++
 qapi-schema.json      | 41 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 120 insertions(+)

-- 
2.7.4

[Qemu-devel] [PATCH for-2.9 V3 1/3] Migration: Don't load vmdesc when xen is enabled

[Zhang Chen]

Xen doesn't need this.

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
---
 migration/savevm.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/migration/savevm.c b/migration/savevm.c
index 0363372..bec6c7e 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1973,6 +1973,10 @@ int qemu_loadvm_state(QEMUFile *f)
         ret = qemu_file_get_error(f);
     }
 
+    if (xen_enabled()) {
+        return ret;
+    }
+
     /*
      * Try to read in the VMDESC section as well, so that dumping tools that
      * intercept our migration stream have the chance to see it.
-- 
2.7.4

Re: [Qemu-devel] [PATCH for-2.9 V3 1/3] Migration: Don't load vmdesc when xen is enabled

[Stefano Stabellini]

On Fri, 9 Dec 2016, Zhang Chen wrote:
> Xen doesn't need this.

Could you please elaborate a bit more on what is the problem exactly,
and why we don't have any issues with migration with Xen today (COLO
use-case aside)?


> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
> ---
>  migration/savevm.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 0363372..bec6c7e 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1973,6 +1973,10 @@ int qemu_loadvm_state(QEMUFile *f)
>          ret = qemu_file_get_error(f);
>      }
>  
> +    if (xen_enabled()) {
> +        return ret;
> +    }
> +
>      /*
>       * Try to read in the VMDESC section as well, so that dumping tools that
>       * intercept our migration stream have the chance to see it.
> -- 
> 2.7.4
> 
> 
> 
> 

Re: [Qemu-devel] [PATCH for-2.9 V3 1/3] Migration: Don't load vmdesc when xen is enabled

[Zhang Chen]

On 12/14/2016 09:00 AM, Stefano Stabellini wrote:
> On Fri, 9 Dec 2016, Zhang Chen wrote:
>> Xen doesn't need this.
> Could you please elaborate a bit more on what is the problem exactly,
> and why we don't have any issues with migration with Xen today (COLO
> use-case aside)?
>

I test COLO without this patch, it seems run normally.
And I review the codes not find why we need this too.
So, I cc the original author wency about this.

CC. wency.

Thanks
Zhang Chen

>> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
>> ---
>>   migration/savevm.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/migration/savevm.c b/migration/savevm.c
>> index 0363372..bec6c7e 100644
>> --- a/migration/savevm.c
>> +++ b/migration/savevm.c
>> @@ -1973,6 +1973,10 @@ int qemu_loadvm_state(QEMUFile *f)
>>           ret = qemu_file_get_error(f);
>>       }
>>   
>> +    if (xen_enabled()) {
>> +        return ret;
>> +    }
>> +
>>       /*
>>        * Try to read in the VMDESC section as well, so that dumping tools that
>>        * intercept our migration stream have the chance to see it.
>> -- 
>> 2.7.4
>>
>>
>>
>>
>
> .
>

-- 
Thanks
Zhang Chen

Re: [Qemu-devel] [PATCH for-2.9 V3 1/3] Migration: Don't load vmdesc when xen is enabled

[Zhang Chen]

On 12/15/2016 02:46 PM, Zhang Chen wrote:
>
>
> On 12/14/2016 09:00 AM, Stefano Stabellini wrote:
>> On Fri, 9 Dec 2016, Zhang Chen wrote:
>>> Xen doesn't need this.
>> Could you please elaborate a bit more on what is the problem exactly,
>> and why we don't have any issues with migration with Xen today (COLO
>> use-case aside)?
>>
>
> I test COLO without this patch, it seems run normally.
> And I review the codes not find why we need this too.
> So, I cc the original author wency about this.
>
> CC. wency.
>

I contacted wency, Here we can ignore this patch.
I will remove this patch in next version.

Thanks
Zhang Chen

> Thanks
> Zhang Chen
>
>>> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
>>> ---
>>>   migration/savevm.c | 4 ++++
>>>   1 file changed, 4 insertions(+)
>>>
>>> diff --git a/migration/savevm.c b/migration/savevm.c
>>> index 0363372..bec6c7e 100644
>>> --- a/migration/savevm.c
>>> +++ b/migration/savevm.c
>>> @@ -1973,6 +1973,10 @@ int qemu_loadvm_state(QEMUFile *f)
>>>           ret = qemu_file_get_error(f);
>>>       }
>>>   +    if (xen_enabled()) {
>>> +        return ret;
>>> +    }
>>> +
>>>       /*
>>>        * Try to read in the VMDESC section as well, so that dumping 
>>> tools that
>>>        * intercept our migration stream have the chance to see it.
>>> -- 
>>> 2.7.4
>>>
>>>
>>>
>>>
>>
>> .
>>
>

-- 
Thanks
Zhang Chen

[Qemu-devel] [PATCH for-2.9 V3 2/3] Add a new qmp command to start/stop replication

[Zhang Chen]

We can call this qmp command to start/stop replication outside of qemu.
Like Xen colo need this function.

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
---
 docs/qmp-commands.txt | 18 ++++++++++++++++++
 migration/colo.c      | 23 +++++++++++++++++++++++
 qapi-schema.json      | 19 +++++++++++++++++++
 3 files changed, 60 insertions(+)

diff --git a/docs/qmp-commands.txt b/docs/qmp-commands.txt
index abf210a..a8e9eb6 100644
--- a/docs/qmp-commands.txt
+++ b/docs/qmp-commands.txt
@@ -432,6 +432,24 @@ Example:
      "arguments": { "enable": true } }
 <- { "return": {} }
 
+xen-set-replication
+-------------------
+
+Enable or disable replication.
+
+Arguments:
+
+- "enable": Enable it or disable it.
+- "primary": True for primary or false for secondary.
+- "failover": Enable failover when stopping replication, but cannot be
+              specified if 'enable' is true (optional, default false).
+
+Example:
+
+-> { "execute": "xen-set-replicate",
+     "arguments": {"enable": true, "primary": false} }
+<- { "return": {} }
+
 migrate
 -------
 
diff --git a/migration/colo.c b/migration/colo.c
index 93c85c5..6fc2ade 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -19,6 +19,8 @@
 #include "qemu/error-report.h"
 #include "qapi/error.h"
 #include "migration/failover.h"
+#include "replication.h"
+#include "qmp-commands.h"
 
 #define COLO_BUFFER_BASE_SIZE (4 * 1024 * 1024)
 
@@ -104,6 +106,27 @@ void colo_do_failover(MigrationState *s)
     }
 }
 
+void qmp_xen_set_replication(bool enable, bool primary,
+                             bool has_failover, bool failover,
+                             Error **errp)
+{
+    ReplicationMode mode = primary ?
+                           REPLICATION_MODE_PRIMARY :
+                           REPLICATION_MODE_SECONDARY;
+
+    if (has_failover && enable) {
+        error_setg(errp, "Parameter 'failover' is only for"
+                   " stopping replication");
+        return;
+    }
+
+    if (enable) {
+        replication_start_all(mode, errp);
+    } else {
+        replication_stop_all(failover, failover ? NULL : errp);
+    }
+}
+
 static void colo_send_message(QEMUFile *f, COLOMessage msg,
                               Error **errp)
 {
diff --git a/qapi-schema.json b/qapi-schema.json
index f3e9bfc..78802f4 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -4676,6 +4676,25 @@
 { 'command': 'xen-load-devices-state', 'data': {'filename': 'str'} }
 
 ##
+# @xen-set-replication
+#
+# Enable or disable replication.
+#
+# @enable: true to enable, false to disable.
+#
+# @primary: true for primary or false for secondary.
+#
+# @failover: #optional true to do failover, false to stop. but cannot be
+#            specified if 'enable' is true. default value is false.
+#
+# Returns: nothing.
+#
+# Since: 2.9
+##
+{ 'command': 'xen-set-replication',
+  'data': { 'enable': 'bool', 'primary': 'bool', '*failover' : 'bool' } }
+
+##
 # @GICCapability:
 #
 # The struct describes capability for a specific GIC (Generic
-- 
2.7.4

[Qemu-devel] [PATCH for-2.9 V3 3/3] Add a new qmp command to do checkpoint, get replication error

[Zhang Chen]

We can call this qmp command to do checkpoint outside of qemu.
Like Xen colo need this function.

Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
---
 docs/qmp-commands.txt | 24 ++++++++++++++++++++++++
 migration/colo.c      | 10 ++++++++++
 qapi-schema.json      | 22 ++++++++++++++++++++++
 3 files changed, 56 insertions(+)

diff --git a/docs/qmp-commands.txt b/docs/qmp-commands.txt
index a8e9eb6..093b7eb 100644
--- a/docs/qmp-commands.txt
+++ b/docs/qmp-commands.txt
@@ -450,6 +450,30 @@ Example:
      "arguments": {"enable": true, "primary": false} }
 <- { "return": {} }
 
+xen-get-replication-error
+-------------------------
+
+Get replication error that occurs when vm is running.
+
+Arguments: None.
+
+Example:
+
+-> { "execute": "xen-get-replication-error" }
+<- { "return": {} }
+
+xen-do-checkpoint
+-----------------
+
+Do checkpoint.
+
+Arguments: None.
+
+Example:
+
+-> { "execute": "xen-do-checkpoint" }
+<- { "return": {} }
+
 migrate
 -------
 
diff --git a/migration/colo.c b/migration/colo.c
index 6fc2ade..1e962f6 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -127,6 +127,16 @@ void qmp_xen_set_replication(bool enable, bool primary,
     }
 }
 
+void qmp_xen_get_replication_error(Error **errp)
+    {
+        replication_get_error_all(errp);
+    }
+
+void qmp_xen_do_checkpoint(Error **errp)
+    {
+        replication_do_checkpoint_all(errp);
+    }
+
 static void colo_send_message(QEMUFile *f, COLOMessage msg,
                               Error **errp)
 {
diff --git a/qapi-schema.json b/qapi-schema.json
index 78802f4..79fe4dd 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -4695,6 +4695,28 @@
   'data': { 'enable': 'bool', 'primary': 'bool', '*failover' : 'bool' } }
 
 ##
+# @xen-get-replication-error
+#
+# Get replication error that occurs when the vm is running.
+#
+# Returns: nothing.
+#
+# Since: 2.9
+##
+{ 'command': 'xen-get-replication-error' }
+
+##
+# @xen-do-checkpoint
+#
+# Do checkpoint.
+#
+# Returns: nothing.
+#
+# Since: 2.9
+##
+{ 'command': 'xen-do-checkpoint' }
+
+##
 # @GICCapability:
 #
 # The struct describes capability for a specific GIC (Generic
-- 
2.7.4