[PATCH 10/16] x86/P2M: p2m_get_page_from_gfn() is HVM-only

[Jan Beulich <jbeulich@suse.com>]

This function is the wrong layer to go through for PV guests. It happens
to work, but produces results which aren't fully consistent with
get_page_from_gfn(). The latter function, however, cannot be used in
map_domain_gfn() as it may not be the host P2M we mean to act on.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/mm/guest_walk.c
+++ b/xen/arch/x86/mm/guest_walk.c
@@ -554,7 +554,9 @@ void *map_domain_gfn(struct p2m_domain *
     }
 
     /* Translate the gfn, unsharing if shared. */
-    page = p2m_get_page_from_gfn(p2m, gfn, &p2mt, NULL, q);
+    page = paging_mode_translate(p2m->domain)
+           ? p2m_get_page_from_gfn(p2m, gfn, &p2mt, NULL, q)
+           : get_page_from_gfn(p2m->domain, gfn_x(gfn), &p2mt, q);
     if ( p2m_is_paging(p2mt) )
     {
         ASSERT(p2m_is_hostp2m(p2m));
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -357,6 +357,8 @@ void __put_gfn(struct p2m_domain *p2m, u
     gfn_unlock(p2m, gfn, 0);
 }
 
+#ifdef CONFIG_HVM
+
 /* Atomically look up a GFN and take a reference count on the backing page. */
 struct page_info *p2m_get_page_from_gfn(
     struct p2m_domain *p2m, gfn_t gfn,
@@ -422,8 +424,6 @@ struct page_info *p2m_get_page_from_gfn(
     return page;
 }
 
-#ifdef CONFIG_HVM
-
 /* Returns: 0 for success, -errno for failure */
 int p2m_set_entry(struct p2m_domain *p2m, gfn_t gfn, mfn_t mfn,
                   unsigned int page_order, p2m_type_t p2mt, p2m_access_t p2ma)