x86/mm: Pull vendor-independent altp2m code out of p2m-ept.c and into p2m.c

No functional changes.

Requested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Alexandru Isaila <aisaila@bitdefender.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Petre Pircalabu <ppircalabu@bitdefender.com>
Acked-by: George Dunlap <george.dunlap@citrix.com>

xen/arch/x86/mm/p2m-ept.c

@@ -1357,13 +1357,7 @@ void p2m_init_altp2m_ept(struct domain *d, unsigned int i)
     struct p2m_domain *hostp2m = p2m_get_hostp2m(d);
     struct ept_data *ept;
 
-    p2m->default_access = hostp2m->default_access;
-    p2m->domain = hostp2m->domain;
-
-    p2m->global_logdirty = hostp2m->global_logdirty;
     p2m->ept.ad = hostp2m->ept.ad;
-    p2m->min_remapped_gfn = gfn_x(INVALID_GFN);
-    p2m->max_mapped_pfn = p2m->max_remapped_gfn = 0;
     ept = &p2m->ept;
     ept->mfn = pagetable_get_pfn(p2m_get_pagetable(p2m));
     d->arch.altp2m_eptp[array_index_nospec(i, MAX_EPTP)] = ept->eptp;

xen/arch/x86/mm/p2m.c

@@ -2562,6 +2562,12 @@ static int p2m_activate_altp2m(struct domain *d, unsigned int idx)
         goto out;
     }
 
+    p2m->default_access = hostp2m->default_access;
+    p2m->domain = hostp2m->domain;
+    p2m->global_logdirty = hostp2m->global_logdirty;
+    p2m->min_remapped_gfn = gfn_x(INVALID_GFN);
+    p2m->max_mapped_pfn = p2m->max_remapped_gfn = 0;
+
     p2m_init_altp2m_ept(d, idx);
 
  out: