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Introduce a new flag, VMS_ARRAY_OF_POINTER_AUTO_ALLOC, for VMSD field. It must be used together with VMS_ARRAY_OF_POINTER. It can be used to allow migration of an array of pointers where the pointers may point to NULLs. Note that we used to allow migration of a NULL pointer within an array that is being migrated. That corresponds to the code around vmstate_info_nullptr where we may get/put one byte showing that the element of an array is NULL. That usage is fine but very limited, it's because even if it will migrate a NULL pointer with a marker, it still works in a way that both src and dest QEMUs must know exactly which elements of the array are non-NULL, so instead of dynamically loading an array (which can have NULL pointers), it actually only verifies the known NULL pointers are still NULL pointers after migration. Also, in that case since dest QEMU knows exactly which element is NULL, which is not NULL, dest QEMU's device code will manage all allocations for the elements before invoking vmstate_load_vmsd(). That's not enough per evolving needs of new device states that may want to provide real dynamic array of pointers, like what Alexander proposed here with the NVMe device migration: https://lore.kernel.org/r/20260317102708.126725-1-alexander@mihalicyn.com This patch is an alternative approach to address the problem. Along with the flag, introduce two new macros: VMSTATE_VARRAY_OF_POINTER_TO_STRUCT_UINT{8|32}_ALLOC() Which will be used very soon in the NVMe series. Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@futurfusion.io> Tested-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@futurfusion.io> Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Juraj Marcin <jmarcin@redhat.com> Link: https://lore.kernel.org/qemu-devel/20260401202844.673494-10-peterx@redhat.com Signed-off-by: Fabiano Rosas <farosas@suse.de>