Can be used to verify a required field exists or validate
state in some other way.
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
include/migration/vmstate.h | 1 +
vmstate.c | 10 +++++++++-
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index 3a1587e..eb90cef 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -101,6 +101,7 @@ enum VMStateFlags {
VMS_MULTIPLY = 0x200, /* multiply "size" field by field_size */
VMS_VARRAY_UINT8 = 0x400, /* Array with size in uint8_t field*/
VMS_VARRAY_UINT32 = 0x800, /* Array with size in uint32_t field*/
+ VMS_MUST_EXIST = 0x1000, /* Field must exist in input */
};
typedef struct {
diff --git a/vmstate.c b/vmstate.c
index fe53735..4943b83 100644
--- a/vmstate.c
+++ b/vmstate.c
@@ -13,7 +13,7 @@ static int vmstate_n_elems(void *opaque, VMStateField *field)
{
int n_elems = 1;
- if (!(field->flags & ~VMS_NONE)) {
+ if (!(field->flags & ~(VMS_NONE | VMS_MUST_EXIST))) {
n_elems = 0;
} else if (field->flags & VMS_ARRAY) {
n_elems = field->num;
@@ -107,6 +107,9 @@ int vmstate_load_state(QEMUFile *f, const
VMStateDescription *vmsd,
}
}
field++;
+ } else if (field->flags & VMS_MUST_EXIST) {
+ fprintf(stderr, "Input validation failed: %s/%s\n", vmsd->name,
field->name);
+ return -1;
}
ret = vmstate_subsection_load(f, vmsd, opaque);
if (ret != 0) {
@@ -148,6 +151,11 @@ void vmstate_save_state(QEMUFile *f, const
VMStateDescription *vmsd,
field->info->put(f, addr, size);
}
}
+ } else {
+ if (field->flags & VMS_MUST_EXIST) {
+ fprintf(stderr, "Input validation failed: %s/%s\n",
vmsd->name, field->name);
+ assert(!(field->flags & VMS_MUST_EXIST));
+ }
}
field++;
}
--
MST
