Commit 53dd370c authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert Committed by Juan Quintela
Browse files

Add migration-capability boolean for postcopy-ram. 



The 'postcopy ram' capability allows postcopy migration of RAM;
note that the migration starts off in precopy mode until
postcopy mode is triggered (see the migrate_start_postcopy
patch later in the series).

Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: default avatarJuan Quintela <quintela@redhat.com>
Reviewed-by: default avatarAmit Shah <amit.shah@redhat.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent 7b89bf27

include/migration/migration.h

+1 −0
Original line number Diff line number Diff line
@@ -186,6 +186,7 @@ void migrate_add_blocker(Error *reason); 
 */

void migrate_del_blocker(Error *reason);



bool migrate_postcopy_ram(void);

bool migrate_zero_blocks(void);



bool migrate_auto_converge(void);

migration/migration.c

+23 −0
Original line number Diff line number Diff line
@@ -578,6 +578,20 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params, 
    for (cap = params; cap; cap = cap->next) {

        s->enabled_capabilities[cap->value->capability] = cap->value->state;

    }



    if (migrate_postcopy_ram()) {

        if (migrate_use_compression()) {

            /* The decompression threads asynchronously write into RAM

             * rather than use the atomic copies needed to avoid

             * userfaulting.  It should be possible to fix the decompression

             * threads for compatibility in future.

             */

            error_report("Postcopy is not currently compatible with "

                         "compression");

            s->enabled_capabilities[MIGRATION_CAPABILITY_X_POSTCOPY_RAM] =

                false;

        }

    }

}



void qmp_migrate_set_parameters(bool has_compress_level,
@@ -956,6 +970,15 @@ void qmp_migrate_set_downtime(double value, Error **errp) 
    max_downtime = (uint64_t)value;

}



bool migrate_postcopy_ram(void)

{

    MigrationState *s;



    s = migrate_get_current();



    return s->enabled_capabilities[MIGRATION_CAPABILITY_X_POSTCOPY_RAM];

}



bool migrate_auto_converge(void)

{

    MigrationState *s;

qapi-schema.json

+5 −1
Original line number Diff line number Diff line
@@ -540,11 +540,15 @@ 
# @auto-converge: If enabled, QEMU will automatically throttle down the guest

#          to speed up convergence of RAM migration. (since 1.6)

#

# @x-postcopy-ram: Start executing on the migration target before all of RAM has

#          been migrated, pulling the remaining pages along as needed. NOTE: If

#          the migration fails during postcopy the VM will fail.  (since 2.5)

#

# Since: 1.2

##

{ 'enum': 'MigrationCapability',

  'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',

           'compress', 'events'] }

           'compress', 'events', 'x-postcopy-ram'] }



##

# @MigrationCapabilityStatus