On Mon, May 11, 2020 at 07:37:06PM +0300, Kirill A. Shutemov wrote:
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.
Currently, we fail boot completely: NULL pointer dereference in subsection_map_init().
Skip creating a memblock for such memory instead and notify user that some memory is not addressable.
Signed-off-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Cc: stable@vger.kernel.org # v4.14
Tested with a hacked QEMU: https://gist.github.com/kiryl/d45eb54110944ff95e544972d8bdac1d
BTW, I was only able to boot with legacy SeaBIOS, not with OVMF. No idea why.