These two patches are the common parts of a larger Xen series[1] fixing several long-standing bugs the handling of foreign[2] pages in Xen guests. The first patch is required to fix get_user_pages[_fast]() with userspace space mappings of such foreign pages. Basically, pte_page() doesn't work so an alternate mechanism is needed to get the page from a VMA and address. By requiring mappings needing this method are 'special' this should not have an impact on the common use cases. The second patch isn't essential but helps with readability of the resulting user of the page flag. For further background reading see: http://xenbits.xen.org/people/dvrabel/grant-improvements-C.pdf Changes in v2: - Add a find_page VMA op instead of the pages field so: a) the size of struct vm_area_struct does not increase; and b) the common code need not handling splitting the pages area. David [1] http://lists.xen.org/archives/html/xen-devel/2015-01/msg00979.html [2] Another guest's page temporarily granted to this guest. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
