[PATCH 04/16] x86/P2M: move map_domain_gfn() (again)

[Jan Beulich <jbeulich@xxxxxxxx>]

The main user is the guest walking code, so move it back there; commit
9a6787cc3809 ("x86/mm: build map_domain_gfn() just once") would perhaps
better have kept it there in the first place. This way it'll only get
built when it's actually needed (and still only once).

This also eliminates one more CONFIG_HVM conditional from p2m.c.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/mm/guest_walk.c
+++ b/xen/arch/x86/mm/guest_walk.c
@@ -535,6 +535,56 @@ guest_walk_tables(const struct vcpu *v,
     return walk_ok;
 }
 
+#if GUEST_PAGING_LEVELS == CONFIG_PAGING_LEVELS
+/*
+ * If the map is non-NULL, we leave this function having acquired an extra ref
+ * on mfn_to_page(*mfn).  In all cases, *pfec contains appropriate
+ * synthetic/structure PFEC_* bits.
+ */
+void *map_domain_gfn(struct p2m_domain *p2m, gfn_t gfn, mfn_t *mfn,
+                     p2m_query_t q, uint32_t *pfec)
+{
+    p2m_type_t p2mt;
+    struct page_info *page;
+
+    if ( !gfn_valid(p2m->domain, gfn) )
+    {
+        *pfec = PFEC_reserved_bit | PFEC_page_present;
+        return NULL;
+    }
+
+    /* Translate the gfn, unsharing if shared. */
+    page = p2m_get_page_from_gfn(p2m, gfn, &p2mt, NULL, q);
+    if ( p2m_is_paging(p2mt) )
+    {
+        ASSERT(p2m_is_hostp2m(p2m));
+        if ( page )
+            put_page(page);
+        p2m_mem_paging_populate(p2m->domain, gfn);
+        *pfec = PFEC_page_paged;
+        return NULL;
+    }
+    if ( p2m_is_shared(p2mt) )
+    {
+        if ( page )
+            put_page(page);
+        *pfec = PFEC_page_shared;
+        return NULL;
+    }
+    if ( !page )
+    {
+        *pfec = 0;
+        return NULL;
+    }
+
+    *pfec = PFEC_page_present;
+    *mfn = page_to_mfn(page);
+    ASSERT(mfn_valid(*mfn));
+
+    return map_domain_page(*mfn);
+}
+#endif
+
 /*
  * Local variables:
  * mode: C
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -1869,58 +1869,6 @@ unsigned long paging_gva_to_gfn(struct v
     return hostmode->gva_to_gfn(v, hostp2m, va, pfec);
 }
 
-#endif /* CONFIG_HVM */
-
-/*
- * If the map is non-NULL, we leave this function having acquired an extra ref
- * on mfn_to_page(*mfn).  In all cases, *pfec contains appropriate
- * synthetic/structure PFEC_* bits.
- */
-void *map_domain_gfn(struct p2m_domain *p2m, gfn_t gfn, mfn_t *mfn,
-                     p2m_query_t q, uint32_t *pfec)
-{
-    p2m_type_t p2mt;
-    struct page_info *page;
-
-    if ( !gfn_valid(p2m->domain, gfn) )
-    {
-        *pfec = PFEC_reserved_bit | PFEC_page_present;
-        return NULL;
-    }
-
-    /* Translate the gfn, unsharing if shared. */
-    page = p2m_get_page_from_gfn(p2m, gfn, &p2mt, NULL, q);
-    if ( p2m_is_paging(p2mt) )
-    {
-        ASSERT(p2m_is_hostp2m(p2m));
-        if ( page )
-            put_page(page);
-        p2m_mem_paging_populate(p2m->domain, gfn);
-        *pfec = PFEC_page_paged;
-        return NULL;
-    }
-    if ( p2m_is_shared(p2mt) )
-    {
-        if ( page )
-            put_page(page);
-        *pfec = PFEC_page_shared;
-        return NULL;
-    }
-    if ( !page )
-    {
-        *pfec = 0;
-        return NULL;
-    }
-
-    *pfec = PFEC_page_present;
-    *mfn = page_to_mfn(page);
-    ASSERT(mfn_valid(*mfn));
-
-    return map_domain_page(*mfn);
-}
-
-#ifdef CONFIG_HVM
-
 static unsigned int mmio_order(const struct domain *d,
                                unsigned long start_fn, unsigned long nr)
 {