x86/mm: free_page_type() is PV-only

While it already has a CONFIG_PV wrapped around its entire body, it is
still uselessly invoking mfn_to_gmfn(), which is about to be replaced.
Avoid morphing this code into even more suspicious shape and remove the
effectively dead code - translated mode has been made impossible for PV
quite some time ago.

Adjust and extend the assertions at the same time: The original
ASSERT(!shadow_mode_refcounts(owner)) really means
ASSERT(!shadow_mode_enabled(owner) || !paging_mode_refcounts(owner)),
which isn't what we want here.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 5e1b061d2a1d8fae2fa608a4dd366c65f915781f..da3bcf7805d253ded65edd23d88a5db169da69f2 100644 (file)
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -2630,7 +2630,6 @@ int free_page_type(struct page_info *page, unsigned long type,
 {
 #ifdef CONFIG_PV
     struct domain *owner = page_get_owner(page);
-    unsigned long gmfn;
     int rc;
 
     if ( likely(owner != NULL) && unlikely(paging_mode_enabled(owner)) )
@@ -2638,11 +2637,11 @@ int free_page_type(struct page_info *page, unsigned long type,
         /* A page table is dirtied when its type count becomes zero. */
         paging_mark_dirty(owner, page_to_mfn(page));
 
-        ASSERT(!shadow_mode_refcounts(owner));
+        ASSERT(shadow_mode_enabled(owner));
+        ASSERT(!paging_mode_refcounts(owner));
+        ASSERT(!paging_mode_translate(owner));
 
-        gmfn = mfn_to_gmfn(owner, mfn_x(page_to_mfn(page)));
-        if ( VALID_M2P(gmfn) )
-            shadow_remove_all_shadows(owner, _mfn(gmfn));
+        shadow_remove_all_shadows(owner, page_to_mfn(page));
     }
 
     if ( !(type & PGT_partial) )