This capability realizes simple source validation by UUID.
It's useful for live migration between hosts.
Signed-off-by: Yury Kotov <yury-kotov@yandex-team.ru>
---
migration/migration.c | 9 +++++++++
migration/migration.h | 1 +
migration/savevm.c | 45 +++++++++++++++++++++++++++++++++++++++++++
qapi/migration.json | 5 ++++-
4 files changed, 59 insertions(+), 1 deletion(-)
diff --git a/migration/migration.c b/migration/migration.c
index 8b9f2fe30a..2391a8d418 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -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;
diff --git a/migration/migration.h b/migration/migration.h
index 3e1ea2b5dc..4f2fe193dc 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -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);
diff --git a/migration/savevm.c b/migration/savevm.c
index 4a86128ac4..493dc24fd2 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -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
}
};
diff --git a/qapi/migration.json b/qapi/migration.json
index 9cfbaf8c6c..82feb5bd39 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -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:
--
2.17.1
* Yury Kotov (yury-kotov@yandex-team.ru) wrote:
> This capability realizes simple source validation by UUID.
> It's useful for live migration between hosts.
>
> Signed-off-by: Yury Kotov <yury-kotov@yandex-team.ru>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
> migration/migration.c | 9 +++++++++
> migration/migration.h | 1 +
> migration/savevm.c | 45 +++++++++++++++++++++++++++++++++++++++++++
> qapi/migration.json | 5 ++++-
> 4 files changed, 59 insertions(+), 1 deletion(-)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index 8b9f2fe30a..2391a8d418 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -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;
> diff --git a/migration/migration.h b/migration/migration.h
> index 3e1ea2b5dc..4f2fe193dc 100644
> --- a/migration/migration.h
> +++ b/migration/migration.h
> @@ -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);
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 4a86128ac4..493dc24fd2 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -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
> }
> };
> diff --git a/qapi/migration.json b/qapi/migration.json
> index 9cfbaf8c6c..82feb5bd39 100644
> --- a/qapi/migration.json
> +++ b/qapi/migration.json
> @@ -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:
> --
> 2.17.1
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
© 2016 - 2025 Red Hat, Inc.