[libvirt] [PATCH v3 2/7] migration: add compress method option

[Nikolay Shirokovskiy]

On 05.02.2016 18:34, Jiri Denemark wrote:
> I still think that to enable migration in a nice backward compatible
> way, a user should use VIR_MIGRATE_COMPRESSED flag *and* optionally
> select the compression algorithm(s) via VIR_MIGRATE_PARAM_COMPRESSION
> parameter. If VIR_MIGRATE_PARAM_COMPRESSION is not used, the hypervisor
> (driver) will choose a default method.
> 
> On Thu, Jan 28, 2016 at 10:04:28 +0300, Nikolay Shirokovskiy wrote:
>> Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy at virtuozzo.com>
>> ---
>>  include/libvirt/libvirt-domain.h | 13 +++++-
>>  src/qemu/qemu_driver.c           | 75 +++++++++++++++++++++++++++++---
>>  src/qemu/qemu_migration.c        | 94 ++++++++++++++++++++++++++++------------
>>  src/qemu/qemu_migration.h        | 16 +++++++
>>  src/qemu/qemu_monitor.c          |  2 +-
>>  src/qemu/qemu_monitor.h          |  1 +
>>  6 files changed, 166 insertions(+), 35 deletions(-)
>>
>> diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h
>> index 65f1618..e868515 100644
>> --- a/include/libvirt/libvirt-domain.h
>> +++ b/include/libvirt/libvirt-domain.h
>> @@ -655,7 +655,7 @@ typedef enum {
>>                                                 * when supported */
>>      VIR_MIGRATE_UNSAFE            = (1 << 9), /* force migration even if it is considered unsafe */
>>      VIR_MIGRATE_OFFLINE           = (1 << 10), /* offline migrate */
>> -    VIR_MIGRATE_COMPRESSED        = (1 << 11), /* compress data during migration */
>> +    VIR_MIGRATE_COMPRESSED        = (1 << 11), /* use default compression method */
> 
> I'd imagine something like "compress data during migration using a
> method selected by the hypervisor or via VIR_MIGRATE_PARAM_COMPRESSION
> parameter.

ok

>> +static int
>> +qemuGetCompression(virTypedParameterPtr params, int nparams,
>> +                   unsigned int flags,
>> +                   qemuMigrationCompressionPtr compression)
>> +{
>> +    size_t i;
>> +
>> +    memset(compression, 0, sizeof(*compression));
> 
> Hmm, I think qemuMigrationCompression structure should be allocated on
> the heap (rather than on the stack) and the allocator would also take
> care of setting appropriate "unspecified" values. And please, move these
> migration related functions in qemu_migrate.c.

ok

> 
> Jirka
>