On Fri, Jan 03, 2025 at 03:49:41PM +0800, Zhiquan Li wrote: > On Intel TDX guest, unaccepted memory is unusable free memory which is > not managed by buddy, until it's accepted by guest. Before that, it > cannot be accessed by the first kernel as well as the kexec'ed kernel. > The kexec'ed kernel will skip these pages and fill in zero data for the > reader of vmcore. > > The dump tool like makedumpfile creates a page descriptor (size 24 > bytes) for each non-free page, including zero data page, but it will not > create descriptor for free pages. If it is not able to distinguish > these unaccepted pages with zero data pages, a certain amount of space > will be wasted in proportion. In fact, as a special kind of free page > the unaccepted pages should be excluded, like the real free pages. > > Export the page type PAGE_UNACCEPTED_MAPCOUNT_VALUE to vmcoreinfo, so > that dump tool can identify whether a page is unaccepted. > > Signed-off-by: Zhiquan Li <zhiquan1.li@xxxxxxxxx> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> -- Kiryl Shutsemau / Kirill A. Shutemov
