On Fri, 3 Jan 2025 at 15:13, Zhiquan Li <zhiquan1.li@xxxxxxxxx> 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. Hi, > > 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> > --- > kernel/vmcore_info.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/kernel/vmcore_info.c b/kernel/vmcore_info.c Please add into admin-guide/kdump/vmcoreinfo.rst if you add more vmcoreinfo. > index 1fec61603ef3..e066d31d08f8 100644 > --- a/kernel/vmcore_info.c > +++ b/kernel/vmcore_info.c > @@ -210,6 +210,10 @@ static int __init crash_save_vmcoreinfo_init(void) > VMCOREINFO_NUMBER(PAGE_HUGETLB_MAPCOUNT_VALUE); > #define PAGE_OFFLINE_MAPCOUNT_VALUE (PGTY_offline << 24) > VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE); > +#ifdef CONFIG_UNACCEPTED_MEMORY > +#define PAGE_UNACCEPTED_MAPCOUNT_VALUE (PGTY_unaccepted << 24) > + VMCOREINFO_NUMBER(PAGE_UNACCEPTED_MAPCOUNT_VALUE); > +#endif > > #ifdef CONFIG_KALLSYMS > VMCOREINFO_SYMBOL(kallsyms_names); > > base-commit: fc033cf25e612e840e545f8d5ad2edd6ba613ed5 > -- > 2.25.1 > >
