Struct ShareableRegion 

pub struct ShareableRegion {
    pub guest_address: u64,
    pub size: u64,
    pub file: Arc<Mappable>,
    pub file_offset: u64,
}

A shareable region of guest memory backed by a file (Unix) or section handle (Windows).

The backing file must already contain committed data for the region — the consumer will map it directly, without any guestmem-managed lazy commitment or fault handling. All bytes in the range must be accessible without triggering SIGSEGV or SIGBUS due to missing backing. Normal OS demand paging and minor faults on first access are still expected; this requirement is specifically incompatible with bitmap-gated access or lazy fault-in schemes.

Fields

guest_address: u64

Guest physical address of this region.

size: u64

Size in bytes.

file: Arc<Mappable>

Backing file/handle, shared via Arc to avoid OS-level dup().

file_offset: u64

Offset into file where this region starts.