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Diffstat (limited to 'docs/devel')
| -rw-r--r-- | docs/devel/migration/main.rst | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/docs/devel/migration/main.rst b/docs/devel/migration/main.rst index 6493c1d2bc..1afe7b9689 100644 --- a/docs/devel/migration/main.rst +++ b/docs/devel/migration/main.rst @@ -444,6 +444,25 @@ The functions to do that are inside a vmstate definition, and are called: This function is called after we save the state of one device (even upon failure, unless the call to pre_save returned an error). +Following are the errp variants of these functions. + +- ``int (*pre_load_errp)(void *opaque, Error **errp);`` + + This function is called before we load the state of one device. + +- ``int (*post_load_errp)(void *opaque, int version_id, Error **errp);`` + + This function is called after we load the state of one device. + +- ``int (*pre_save_errp)(void *opaque, Error **errp);`` + + This function is called before we save the state of one device. + +New impls should preferentally use 'errp' variants of these +methods and existing impls incrementally converted. +The variants without 'errp' are intended to be removed +once all usage is converted. + Example: You can look at hpet.c, that uses the first three functions to massage the state that is transferred. |