Glauber de Oliveira Costa wrote: > On 8/8/07, Nakajima, Jun <jun.nakajima@xxxxxxxxx> wrote: > > Glauber de Oliveira Costa wrote: > > > Hi folks, > > > > > > After some time away from it, and a big rebase as a consequence, here is > > > the updated version of paravirt_ops for x86_64, heading to inclusion. > > > > > > Your criticism is of course, very welcome. > > > > > > Have fun > > > > Do you assume that the kernel ougtht to use 2MB pages for its mappings > > (e.g. initilal text/data, direct mapping of physical memory) under your > > paravirt_ops? As far as I look at the patches, I don't find one. > > I don't think how it could be relevant here. lguest kernel does use > 2MB pages, and it goes smootly. For 2MB pages, we will update the page > tables in the very same way, and in the very places we did before. > Just that the operations can now be overwritten. > > So, unless I'm very wrong, it only makes sense to talk about not > supporting large pages in the guest level. But it is not a > paravirt_ops problem. Some MMU-related PV techiniques (including Xen, and direct paging mode for Xen/KVM) need to write-protect page tables, avoiding to use 2MB pages when mapping page tables. Looks like you did not, and that exaplains why the patches are missing the relevant (many) paravirt_ops in include/asm-x86_64/pgalloc.h, for example, compared with the i386 tree. Jun --- Intel Open Source Technology Center _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
