706     start: VirtAddr,  field
713     pub fn new(start: VirtAddr, size: usize) -> Self {  in new()
714         VirtRegion { start, size }  in new()
719     pub fn start(&self) -> VirtAddr {  in start()  method
720         self.start  in start()
726         return self.start().add(self.size);  in end()
732     pub fn between(start: VirtAddr, end: VirtAddr) -> Option<Self> {  in between()
733         if unlikely(end.data() <= start.data()) {  in between()
736         let size = end.data() - start.data();  in between()
737         return Some(VirtRegion::new(start, size));  in between()
744         let start = self.start.max(other.start);  in intersect()  localVariable
746         return VirtRegion::between(start, end);  in intersect()
751     pub fn set_start(&mut self, start: VirtAddr) {  in set_start()
752         self.start = start;  in set_start()
775         return VirtRegion::new(self.start, round_up_to_page_size(self.size));  in round_up_size_to_page()
786             VirtPageFrame::new(self.start),  in iter_pages()
795         return Self::between(self.start(), region.start());  in before()
815         let offset = vaddr.data() - self.start().data();  in rebase()
816         let new_start = new_base.start().data() + offset;  in rebase()
822         return self.start() <= addr && addr < self.end();  in contains()
828             VirtPageFrame::new(self.start()),  in pages()
842         return self.start.cmp(&other.start);  in cmp()