diff options
| -rw-r--r-- | include/migration/vmstate.h | 4 | ||||
| -rw-r--r-- | migration/vmstate.c | 40 |
2 files changed, 42 insertions, 2 deletions
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index 63e7b02e05..f2dbf8410a 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -253,6 +253,10 @@ extern const VMStateInfo vmstate_info_uint16; extern const VMStateInfo vmstate_info_uint32; extern const VMStateInfo vmstate_info_uint64; +/** Put this in the stream when migrating a null pointer.*/ +#define VMS_NULLPTR_MARKER (0x30U) /* '0' */ +extern const VMStateInfo vmstate_info_nullptr; + extern const VMStateInfo vmstate_info_float64; extern const VMStateInfo vmstate_info_cpudouble; diff --git a/migration/vmstate.c b/migration/vmstate.c index 836a7a481b..78b3cd48e7 100644 --- a/migration/vmstate.c +++ b/migration/vmstate.c @@ -117,7 +117,11 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, if (field->flags & VMS_ARRAY_OF_POINTER) { curr_elem = *(void **)curr_elem; } - if (field->flags & VMS_STRUCT) { + if (!curr_elem) { + /* if null pointer check placeholder and do not follow */ + assert(field->flags & VMS_ARRAY_OF_POINTER); + ret = vmstate_info_nullptr.get(f, curr_elem, size, NULL); + } else if (field->flags & VMS_STRUCT) { ret = vmstate_load_state(f, field->vmsd, curr_elem, field->vmsd->version_id); } else { @@ -332,7 +336,11 @@ void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd, assert(curr_elem); curr_elem = *(void **)curr_elem; } - if (field->flags & VMS_STRUCT) { + if (!curr_elem) { + /* if null pointer write placeholder and do not follow */ + assert(field->flags & VMS_ARRAY_OF_POINTER); + vmstate_info_nullptr.put(f, curr_elem, size, NULL, NULL); + } else if (field->flags & VMS_STRUCT) { vmstate_save_state(f, field->vmsd, curr_elem, vmdesc_loop); } else { field->info->put(f, curr_elem, size, field, vmdesc_loop); @@ -747,6 +755,34 @@ const VMStateInfo vmstate_info_uint64 = { .put = put_uint64, }; +static int get_nullptr(QEMUFile *f, void *pv, size_t size, VMStateField *field) + +{ + if (qemu_get_byte(f) == VMS_NULLPTR_MARKER) { + return 0; + } + error_report("vmstate: get_nullptr expected VMS_NULLPTR_MARKER"); + return -EINVAL; +} + +static int put_nullptr(QEMUFile *f, void *pv, size_t size, + VMStateField *field, QJSON *vmdesc) + +{ + if (pv == NULL) { + qemu_put_byte(f, VMS_NULLPTR_MARKER); + return 0; + } + error_report("vmstate: put_nullptr must be called with pv == NULL"); + return -EINVAL; +} + +const VMStateInfo vmstate_info_nullptr = { + .name = "uint64", + .get = get_nullptr, + .put = put_nullptr, +}; + /* 64 bit unsigned int. See that the received value is the same than the one in the field */ |