SGX_ENCL_PAGE_VA_OFFSET_MASK
unsigned long va_offset = encl_page->desc & SGX_ENCL_PAGE_VA_OFFSET_MASK;
unsigned long va_offset = encl_page->desc & SGX_ENCL_PAGE_VA_OFFSET_MASK;
encl_page->desc &= ~SGX_ENCL_PAGE_VA_OFFSET_MASK;
(SGX_ENCL_PAGE_VA_OFFSET_MASK >> 3) + 1);