KVM: x86/mmu: Rename goal_gfn to next_last_level_gfn

The goal_gfn field in tdp_iter can be misleading as it implies that it
is the iterator's final goal. It is really a target for the lowest gfn
mapped by the leaf level SPTE the iterator will traverse towards. Change
the field's name to be more precise.

Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210202185734.1680553-13-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/tdp_iter.c

@@ -22,21 +22,21 @@ static gfn_t round_gfn_for_level(gfn_t gfn, int level)
 
 /*
  * Sets a TDP iterator to walk a pre-order traversal of the paging structure
- * rooted at root_pt, starting with the walk to translate goal_gfn.
+ * rooted at root_pt, starting with the walk to translate next_last_level_gfn.
  */
 void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level,
-		    int min_level, gfn_t goal_gfn)
+		    int min_level, gfn_t next_last_level_gfn)
 {
 	WARN_ON(root_level < 1);
 	WARN_ON(root_level > PT64_ROOT_MAX_LEVEL);
 
-	iter->goal_gfn = goal_gfn;
+	iter->next_last_level_gfn = next_last_level_gfn;
 	iter->root_level = root_level;
 	iter->min_level = min_level;
 	iter->level = root_level;
 	iter->pt_path[iter->level - 1] = root_pt;
 
-	iter->gfn = round_gfn_for_level(iter->goal_gfn, iter->level);
+	iter->gfn = round_gfn_for_level(iter->next_last_level_gfn, iter->level);
 	tdp_iter_refresh_sptep(iter);
 
 	iter->valid = true;
@@ -82,7 +82,7 @@ static bool try_step_down(struct tdp_iter *iter)
 
 	iter->level--;
 	iter->pt_path[iter->level - 1] = child_pt;
-	iter->gfn = round_gfn_for_level(iter->goal_gfn, iter->level);
+	iter->gfn = round_gfn_for_level(iter->next_last_level_gfn, iter->level);
 	tdp_iter_refresh_sptep(iter);
 
 	return true;
@@ -106,7 +106,7 @@ static bool try_step_side(struct tdp_iter *iter)
 		return false;
 
 	iter->gfn += KVM_PAGES_PER_HPAGE(iter->level);
-	iter->goal_gfn = iter->gfn;
+	iter->next_last_level_gfn = iter->gfn;
 	iter->sptep++;
 	iter->old_spte = READ_ONCE(*iter->sptep);
 
@@ -166,13 +166,13 @@ void tdp_iter_next(struct tdp_iter *iter)
  */
 void tdp_iter_refresh_walk(struct tdp_iter *iter)
 {
-	gfn_t goal_gfn = iter->goal_gfn;
+	gfn_t next_last_level_gfn = iter->next_last_level_gfn;
 
-	if (iter->gfn > goal_gfn)
-		goal_gfn = iter->gfn;
+	if (iter->gfn > next_last_level_gfn)
+		next_last_level_gfn = iter->gfn;
 
 	tdp_iter_start(iter, iter->pt_path[iter->root_level - 1],
-		       iter->root_level, iter->min_level, goal_gfn);
+		       iter->root_level, iter->min_level, next_last_level_gfn);
 }
 
 u64 *tdp_iter_root_pt(struct tdp_iter *iter)

arch/x86/kvm/mmu/tdp_iter.h

@@ -15,7 +15,7 @@ struct tdp_iter {
 	 * The iterator will traverse the paging structure towards the mapping
 	 * for this GFN.
 	 */
-	gfn_t goal_gfn;
+	gfn_t next_last_level_gfn;
 	/* Pointers to the page tables traversed to reach the current SPTE */
 	u64 *pt_path[PT64_ROOT_MAX_LEVEL];
 	/* A pointer to the current SPTE */
@@ -52,7 +52,7 @@ struct tdp_iter {
 u64 *spte_to_child_pt(u64 pte, int level);
 
 void tdp_iter_start(struct tdp_iter *iter, u64 *root_pt, int root_level,
-		    int min_level, gfn_t goal_gfn);
+		    int min_level, gfn_t next_last_level_gfn);
 void tdp_iter_next(struct tdp_iter *iter);
 void tdp_iter_refresh_walk(struct tdp_iter *iter);
 u64 *tdp_iter_root_pt(struct tdp_iter *iter);