Re: [PATCH v3 21/21] migration: Add zstd compression multifd support

[Juan Quintela]

Eric Blake <address@hidden> wrote:
> On 1/23/20 5:58 AM, Juan Quintela wrote:
>> Signed-off-by: Juan Quintela <address@hidden>
>> ---
>>   hw/core/qdev-properties.c    |   2 +-
>>   migration/Makefile.objs      |   1 +
>>   migration/migration.c        |   6 +
>>   migration/multifd-zstd.c     | 304 +++++++++++++++++++++++++++++++++++
>>   migration/multifd.h          |  20 +++
>>   migration/ram.c              |   1 -
>>   qapi/migration.json          |   2 +-
>>   tests/qtest/migration-test.c |  10 ++
>>   8 files changed, 343 insertions(+), 3 deletions(-)
>>   create mode 100644 migration/multifd-zstd.c
>>
>
>> +++ b/migration/Makefile.objs
>> @@ -9,6 +9,7 @@ common-obj-y += qjson.o
>>   common-obj-y += block-dirty-bitmap.o
>>   common-obj-y += multifd.o
>>   common-obj-y += multifd-zlib.o
>> +common-obj-$(CONFIG_ZSTD) += multifd-zstd.o

Hi

> zstd support is conditional...

yeap.

>> +++ b/qapi/migration.json
>> @@ -499,7 +499,7 @@
>>   #
>>   ##
>>   { 'enum': 'MultifdCompress',
>> -  'data': [ 'none', 'zlib' ] }
>> +  'data': [ 'none', 'zlib', 'zstd' ] }
>
> ...so I would expect an 'if' conditional here when declaring the
> enum. It also needs documentation.

I fully agree about the documentation part.

But if you are setting zstd, and zstd is compiled out, we are giving the
error showed in the code shown below.

I am open to do anyother way.  I don't speak qapi natively O:-)

Later, Juan.



diff --git a/migration/migration.c b/migration/migration.c
index d25fdb3e6b..f0d5ade1df 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1256,6 +1256,12 @@ static bool migrate_params_check(MigrationParameters 
*params, Error **errp)
                    "is invalid, it must be in the range of 1 to 10000 ms");
        return false;
     }
+    if (params->has_multifd_compress &&
+       params->multifd_compress == MULTIFD_COMPRESS_ZSTD &&
+       !multifd_compress_zstd_is_enabled()) {
+        error_setg(errp, "The multifd compression method zstd is compiled 
out");
+        return false;
+    }
     return true;
 }