diff options
| author | Aaron Lindsay <aaron@os.amperecomputing.com> | 2019-01-21 10:23:13 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2019-01-21 10:38:55 +0000 |
| commit | 8c07559fc7ee132e2145ad09299a08c10ebe7804 (patch) | |
| tree | 78da6eb7ab56ca982e0f95a5ed341c510f284b26 | |
| parent | 8733d762d5e089a017ac7c5bc71077a8d75d1b46 (diff) | |
migration: Add post_save function to VMStateDescription
In some cases it may be helpful to modify state before saving it for
migration, and then modify the state back after it has been saved. The
existing pre_save function provides half of this functionality. This
patch adds a post_save function to provide the second half.
Signed-off-by: Aaron Lindsay <aclindsa@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: 20181211151945.29137-2-aaron@os.amperecomputing.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
| -rw-r--r-- | docs/devel/migration.rst | 9 | ||||
| -rw-r--r-- | include/migration/vmstate.h | 1 | ||||
| -rw-r--r-- | migration/vmstate.c | 13 |
3 files changed, 20 insertions, 3 deletions
diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst index e7658ab050..220059679a 100644 --- a/docs/devel/migration.rst +++ b/docs/devel/migration.rst @@ -419,8 +419,13 @@ The functions to do that are inside a vmstate definition, and are called: This function is called before we save the state of one device. -Example: You can look at hpet.c, that uses the three function to -massage the state that is transferred. +- ``int (*post_save)(void *opaque);`` + + This function is called after we save the state of one device + (even upon failure, unless the call to pre_save returned an error). + +Example: You can look at hpet.c, that uses the first three functions +to massage the state that is transferred. The ``VMSTATE_WITH_TMP`` macro may be useful when the migration data doesn't match the stored device data well; it allows an diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index 61bef3ef5c..067b126cf1 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -185,6 +185,7 @@ struct VMStateDescription { int (*pre_load)(void *opaque); int (*post_load)(void *opaque, int version_id); int (*pre_save)(void *opaque); + int (*post_save)(void *opaque); bool (*needed)(void *opaque); const VMStateField *fields; const VMStateDescription **subsections; diff --git a/migration/vmstate.c b/migration/vmstate.c index 80b59009aa..e2bbb7b5f7 100644 --- a/migration/vmstate.c +++ b/migration/vmstate.c @@ -390,6 +390,9 @@ int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd, if (ret) { error_report("Save of field %s/%s failed", vmsd->name, field->name); + if (vmsd->post_save) { + vmsd->post_save(opaque); + } return ret; } @@ -415,7 +418,15 @@ int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd, json_end_array(vmdesc); } - return vmstate_subsection_save(f, vmsd, opaque, vmdesc); + ret = vmstate_subsection_save(f, vmsd, opaque, vmdesc); + + if (vmsd->post_save) { + int ps_ret = vmsd->post_save(opaque); + if (!ret) { + ret = ps_ret; + } + } + return ret; } static const VMStateDescription * |