A 5-level paging capable machine can have memory above 46-bit in the physical address space. This memory is only addressable in the 5-level paging mode: we don't have enough virtual address space to create direct mapping for such memory in the 4-level paging mode. Tested with a hacked QEMU: https://gist.github.com/kiryl/d45eb54110944ff95e544972d8bdac1d v2: - Fix boot with KASLR enabled on such machines; - Better error message; Kirill A. Shutemov (2): x86/mm: Fix boot with some memory above MAXMEM x86/boot/KASLR: Fix boot with some memory above MAXMEM arch/x86/boot/compressed/kaslr.c | 11 +++++++++++ arch/x86/kernel/e820.c | 24 ++++++++++++++++++++++-- 2 files changed, 33 insertions(+), 2 deletions(-) -- 2.26.2
