Commit 02affd41 authored by Peter Xu's avatar Peter Xu Committed by Juan Quintela
Browse files

qmp/migration: new command migrate-recover 



The first allow-oob=true command.  It's used on destination side when
the postcopy migration is paused and ready for a recovery.  After
execution, a new migration channel will be established for postcopy to
continue.

Reviewed-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Message-Id: <20180502104740.12123-21-peterx@redhat.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
---
s/2.12/2.13/
parent e1b1b1bc

migration/migration.c

+24 −0
Original line number Diff line number Diff line
@@ -1475,6 +1475,30 @@ void qmp_migrate_incoming(const char *uri, Error **errp) 
    once = false;

}



void qmp_migrate_recover(const char *uri, Error **errp)

{

    MigrationIncomingState *mis = migration_incoming_get_current();



    if (mis->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {

        error_setg(errp, "Migrate recover can only be run "

                   "when postcopy is paused.");

        return;

    }



    if (atomic_cmpxchg(&mis->postcopy_recover_triggered,

                       false, true) == true) {

        error_setg(errp, "Migrate recovery is triggered already");

        return;

    }



    /*

     * Note that this call will never start a real migration; it will

     * only re-setup the migration stream and poke existing migration

     * to continue using that newly established channel.

     */

    qemu_start_incoming_migration(uri, errp);

}



bool migration_is_blocked(Error **errp)

{

    if (qemu_savevm_state_blocked(errp)) {

migration/migration.h

+1 −0
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ struct MigrationIncomingState { 
    struct PostcopyBlocktimeContext *blocktime_ctx;



    /* notify PAUSED postcopy incoming migrations to try to continue */

    bool postcopy_recover_triggered;

    QemuSemaphore postcopy_pause_sem_dst;

    QemuSemaphore postcopy_pause_sem_fault;

};

migration/savevm.c

+3 −0
Original line number Diff line number Diff line
@@ -2190,6 +2190,9 @@ static bool postcopy_pause_incoming(MigrationIncomingState *mis) 
{

    trace_postcopy_pause_incoming();



    /* Clear the triggered bit to allow one recovery */

    mis->postcopy_recover_triggered = false;



    migrate_set_state(&mis->state, MIGRATION_STATUS_POSTCOPY_ACTIVE,

                      MIGRATION_STATUS_POSTCOPY_PAUSED);

qapi/migration.json

+20 −0
Original line number Diff line number Diff line
@@ -1191,3 +1191,23 @@ 
# Since: 2.9

##

{ 'command': 'xen-colo-do-checkpoint' }



##

# @migrate-recover:

#

# Provide a recovery migration stream URI.

#

# @uri: the URI to be used for the recovery of migration stream.

#

# Returns: nothing.

#

# Example:

#

# -> { "execute": "migrate-recover",

#      "arguments": { "uri": "tcp:192.168.1.200:12345" } }

# <- { "return": {} }

#

# Since: 2.13

##

{ 'command': 'migrate-recover', 'data': { 'uri': 'str' },

  'allow-oob': true }