[PATCH 05/11] x86/shadow: move bogus HVM checks in sh_pagetable_dying()

[Jan Beulich]

Perhaps these should have been dropped right in 2fb2dee1ac62 ("x86/mm:
pagetable_dying() is HVM-only"). Convert both to assertions, noting that
in particular the one in the 3-level variant of the function comes too
late anyway - first thing there we access the HVM part of a union.

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

--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -3780,6 +3780,8 @@ static void cf_check sh_pagetable_dying(
     unsigned long l3gfn;
     mfn_t l3mfn;
 
+    ASSERT(is_hvm_domain(d));
+
     gcr3 = v->arch.hvm.guest_cr[3];
     /* fast path: the pagetable belongs to the current context */
     if ( gcr3 == gpa )
@@ -3822,7 +3824,7 @@ static void cf_check sh_pagetable_dying(
                    : shadow_hash_lookup(d, mfn_x(gmfn), SH_type_l2_pae_shadow);
         }
 
-        if ( mfn_valid(smfn) && is_hvm_domain(d) )
+        if ( mfn_valid(smfn) )
         {
             gmfn = _mfn(mfn_to_page(smfn)->v.sh.back);
             mfn_to_page(gmfn)->pagetable_dying = true;
@@ -3854,6 +3856,8 @@ static void cf_check sh_pagetable_dying(
     mfn_t smfn, gmfn;
     p2m_type_t p2mt;
 
+    ASSERT(is_hvm_domain(d));
+
     gmfn = get_gfn_query(d, _gfn(gpa >> PAGE_SHIFT), &p2mt);
     paging_lock(d);
 
@@ -3863,7 +3867,7 @@ static void cf_check sh_pagetable_dying(
     smfn = shadow_hash_lookup(d, mfn_x(gmfn), SH_type_l4_64_shadow);
 #endif
 
-    if ( mfn_valid(smfn) && is_hvm_domain(d) )
+    if ( mfn_valid(smfn) )
     {
         mfn_to_page(gmfn)->pagetable_dying = true;
         shadow_unhook_mappings(d, smfn, 1/* user pages only */);