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 David [1] http://lists.xen.org/archives/html/xen-devel/2015-01/msg00326.html [2] Another guest's page temporarily granted to this guest. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
