rust/vmstate: Relax array check when build varray in vmstate_struct

The varry of structure created by vmstate_struct is different with
vmstate_of. This is because vmstate_struct uses the `vmsd` to traverse
the vmstates of structure's fields, rather than treating the structure
directly as a well-defined vmstate.

Therefore, there's no need to check array flag when building varray by
vmstate_struct.

Signed-off-by: Zhao Liu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Bonzini <[email protected]>

Author: trueptolemy

rust/qemu-api/src/vmstate.rs

@@ -275,14 +275,20 @@ impl VMStateField {
     }
 
     #[must_use]
-    pub const fn with_varray_flag(mut self, flag: VMStateFlags) -> VMStateField {
-        assert!((self.flags.0 & VMStateFlags::VMS_ARRAY.0) != 0);
+    pub const fn with_varray_flag_unchecked(mut self, flag: VMStateFlags) -> VMStateField {
         self.flags = VMStateFlags(self.flags.0 & !VMStateFlags::VMS_ARRAY.0);
         self.flags = VMStateFlags(self.flags.0 | flag.0);
         self.num = 0; // varray uses num_offset instead of num.
         self
     }
 
+    #[must_use]
+    #[allow(unused_mut)]
+    pub const fn with_varray_flag(mut self, flag: VMStateFlags) -> VMStateField {
+        assert!((self.flags.0 & VMStateFlags::VMS_ARRAY.0) != 0);
+        self.with_varray_flag_unchecked(flag)
+    }
+
     #[must_use]
     pub const fn with_varray_multiply(mut self, num: u32) -> VMStateField {
         assert!(num <= 0x7FFF_FFFFu32);
@@ -454,7 +460,7 @@ macro_rules! vmstate_struct {
             flags: $crate::bindings::VMStateFlags::VMS_STRUCT,
             vmsd: $vmsd,
             ..$crate::zeroable::Zeroable::ZERO
-         } $(.with_varray_flag(
+         } $(.with_varray_flag_unchecked(
                   $crate::call_func_with_field!(
                       $crate::vmstate::vmstate_varray_flag,
                       $struct_name,