__MD_SHADOW_START
KASSERT(va >= __MD_SHADOW_START && va < __MD_SHADOW_END);
#define __MD_SHADOW_END (__MD_SHADOW_START + __MD_SHADOW_SIZE)
#define __MD_SHAD_MAIN_START (__MD_SHADOW_START)
#define __MD_SHAD_KERN_START (__MD_SHADOW_START + 0x8000000000ULL)