* Michael S. Tsirkin (m...@redhat.com) wrote:
> 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;
I think your intent here is just to misuse the field_exist function pointer
as a call for a different reason as a hook for a validator; is it really worth
misusing it like that or is something more explicit worth it?
Perhaps something passed an Error** so it could pass back what was wrong?
> }
> 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));
Wrong message for the save side.
Dave
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
