>>> On 07.09.12 at 09:02, Huang Ying <ying.huang@xxxxxxxxx> wrote: > On Fri, 2012-09-07 at 07:40 +0100, Jan Beulich wrote: >> At least for Xen Dom0 it is very relevant to set the _PAGE_IO bit when >> ioremap-ing (non-RAM) areas, as that flag suppresses the PFN -> MFN >> translation otherwise done in PV guests. (The offending commit was >> 81e88fdc432a1552401d6e91a984dcccce72b8dc.) > > If my understanding were correct, ghes_ioremap_pfn_nmi normally only map > RAM. But not RAM in the sense of what is seen as usable memory in the E820 map. What you're mapping here is reserved memory, and that is (from the perspective of the kernel and Xen) non-RAM. The fact that it is RAM from a machine perspective is manifested by the mapping not needing to be done UC or alike. Jan -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
