>> Don't we need to pass vaddr down to all routines so that they select >> appropriate tables? You seem to always be choosing the first one. > IIUC, we clear whole page table subtree covered by one pgd entry. > So, no, there's no need to pass vaddr down. Just pointer to page table > entry is enough. > > But I know virtually nothing about Xen. Please re-check my reasoning. Yes, we effectively remove the whole page table for vaddr so I guess it's OK. > > I would also appreciate help with getting x86 Xen code work with 5-level > paging enabled. For now I make CONFIG_XEN dependent on !CONFIG_X86_5LEVEL. Hmmm... that's a problem since this requires changes in the hypervisor and even if/when these changes are made older version of hypervisor still will not be able to run those guests. This affects only PV guests and there is a series under review that provides clean code separation with CONFIG_XEN_PV but because, for example, dom0 (Xen control domain) is PV this will significantly limit availability of dom0-capable kernels (because I assume distros will want to have CONFIG_X86_5LEVEL). > > Fixup: Yes, that works. (But then it worked even without this change because problems caused by missing the flush would be intermittent. And a joy to debug). -boris
