• Jeremy Fitzhardinge's avatar
    x86: add _PAGE_IOMAP pte flag for IO mappings · be43d728
    Jeremy Fitzhardinge authored
    Use one of the software-defined PTE bits to indicate that a mapping is
    intended for an IO address.  On native hardware this is irrelevent,
    since a physical address is a physical address.  But in a virtual
    environment, physical addresses are also virtualized, so there needs
    to be some way to distinguish between pseudo-physical addresses and
    actual hardware addresses; _PAGE_IOMAP indicates this intent.
    
    By default, __supported_pte_mask masks out _PAGE_IOMAP, so it doesn't
    even appear in the final pagetable.
    Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    be43d728
init_32.c 30 KB