Commit b9d68df6 authored by Yury Kotov's avatar Yury Kotov Committed by Dr. David Alan Gilbert
Browse files

migration: Add validate-uuid capability 



This capability realizes simple source validation by UUID.
It's useful for live migration between hosts.

Signed-off-by: default avatarYury Kotov <yury-kotov@yandex-team.ru>
Message-Id: <20190903162246.18524-2-yury-kotov@yandex-team.ru>
Reviewed-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
parent 3b348706

migration/migration.c

+9 −0
Original line number Diff line number Diff line
@@ -2140,6 +2140,15 @@ bool migrate_ignore_shared(void) 
    return s->enabled_capabilities[MIGRATION_CAPABILITY_X_IGNORE_SHARED];

}



bool migrate_validate_uuid(void)

{

    MigrationState *s;



    s = migrate_get_current();



    return s->enabled_capabilities[MIGRATION_CAPABILITY_VALIDATE_UUID];

}



bool migrate_use_events(void)

{

    MigrationState *s;

migration/migration.h

+1 −0
Original line number Diff line number Diff line
@@ -290,6 +290,7 @@ bool migrate_postcopy_ram(void); 
bool migrate_zero_blocks(void);

bool migrate_dirty_bitmaps(void);

bool migrate_ignore_shared(void);

bool migrate_validate_uuid(void);



bool migrate_auto_converge(void);

bool migrate_use_multifd(void);

migration/savevm.c

+45 −0
Original line number Diff line number Diff line
@@ -256,6 +256,7 @@ typedef struct SaveState { 
    uint32_t target_page_bits;

    uint32_t caps_count;

    MigrationCapability *capabilities;

    QemuUUID uuid;

} SaveState;



static SaveState savevm_state = {
@@ -307,6 +308,7 @@ static int configuration_pre_save(void *opaque) 
            state->capabilities[j++] = i;

        }

    }

    state->uuid = qemu_uuid;



    return 0;

}
@@ -464,6 +466,48 @@ static const VMStateDescription vmstate_capabilites = { 
    }

};



static bool vmstate_uuid_needed(void *opaque)

{

    return qemu_uuid_set && migrate_validate_uuid();

}



static int vmstate_uuid_post_load(void *opaque, int version_id)

{

    SaveState *state = opaque;

    char uuid_src[UUID_FMT_LEN + 1];

    char uuid_dst[UUID_FMT_LEN + 1];



    if (!qemu_uuid_set) {

        /*

         * It's warning because user might not know UUID in some cases,

         * e.g. load an old snapshot

         */

        qemu_uuid_unparse(&state->uuid, uuid_src);

        warn_report("UUID is received %s, but local uuid isn't set",

                     uuid_src);

        return 0;

    }

    if (!qemu_uuid_is_equal(&state->uuid, &qemu_uuid)) {

        qemu_uuid_unparse(&state->uuid, uuid_src);

        qemu_uuid_unparse(&qemu_uuid, uuid_dst);

        error_report("UUID received is %s and local is %s", uuid_src, uuid_dst);

        return -EINVAL;

    }

    return 0;

}



static const VMStateDescription vmstate_uuid = {

    .name = "configuration/uuid",

    .version_id = 1,

    .minimum_version_id = 1,

    .needed = vmstate_uuid_needed,

    .post_load = vmstate_uuid_post_load,

    .fields = (VMStateField[]) {

        VMSTATE_UINT8_ARRAY_V(uuid.data, SaveState, sizeof(QemuUUID), 1),

        VMSTATE_END_OF_LIST()

    }

};



static const VMStateDescription vmstate_configuration = {

    .name = "configuration",

    .version_id = 1,
@@ -478,6 +522,7 @@ static const VMStateDescription vmstate_configuration = { 
    .subsections = (const VMStateDescription*[]) {

        &vmstate_target_page_bits,

        &vmstate_capabilites,

        &vmstate_uuid,

        NULL

    }

};

qapi/migration.json

+4 −1
Original line number Diff line number Diff line
@@ -415,6 +415,9 @@ 
#

# @x-ignore-shared: If enabled, QEMU will not migrate shared memory (since 4.0)

#

# @validate-uuid: Send the UUID of the source to allow the destination

#                 to ensure it is the same. (since 4.2)

#

# Since: 1.2

##

{ 'enum': 'MigrationCapability',
@@ -422,7 +425,7 @@ 
           'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram',

           'block', 'return-path', 'pause-before-switchover', 'multifd',

           'dirty-bitmaps', 'postcopy-blocktime', 'late-block-activate',

           'x-ignore-shared' ] }

           'x-ignore-shared', 'validate-uuid' ] }



##

# @MigrationCapabilityStatus: