On Sat, Nov 10, 2012 at 03:42:24PM +0000, Christoffer Dall wrote:

I wonder whether the dependency is quite right here. Functionally, we're
only dependent on LPAE but it doesn't make sense if !ARM_VIRT_EXT. In
fact, I start to question whether CONFIG_ARM_VIRT_EXT is worthwhile at
all as it stands. Maybe it would be better to add the LPAE dependency
there and make the hyp_stub stuff that's currently in mainline
unconditional?

+/*
+ * This version actually frees the underlying pmds for all pgds in range and
+ * clear the pgds themselves afterwards.
+ */
+void hyp_idmap_teardown(pgd_t *hyp_pgd)
+{
+	unsigned long addr, end;
+	unsigned long next;
+	pgd_t *pgd = hyp_pgd;
+
+	addr = virt_to_phys(__hyp_idmap_text_start);
+	end = virt_to_phys(__hyp_idmap_text_end);
+
+	pgd += pgd_index(addr);
+	do {
+		next = pgd_addr_end(addr, end);
+		if (!pgd_none_or_clear_bad(pgd))
+			hyp_idmap_del_pmd(pgd, addr);
+	} while (pgd++, addr = next, addr < end);
+}
+EXPORT_SYMBOL_GPL(hyp_idmap_teardown);
+
+void hyp_idmap_setup(pgd_t *hyp_pgd)
+{
+	identity_mapping_add(hyp_pgd, __hyp_idmap_text_start,
+			     __hyp_idmap_text_end, PMD_SECT_AP1);
+}
+EXPORT_SYMBOL_GPL(hyp_idmap_setup);
+#endif

Again, do we need these exports?

I also think it might be cleaner to declare the hyp_pgd next to the
idmap_pgd then add the hyp_idmap_setup code to init_static_idmap, so
that we don't add new entry points to this file. The teardown can all be
moved into the kvm/ code as it doesn't need any of the existing idmap
functions.

Will