[PATCH v2 8/8] KVM: MMU: Eliminate redundant temporaries in FNAME(fetch)

[Avi Kivity <avi@redhat.com>]

'level' and 'sptep' are aliases for 'interator.level' and 'iterator.sptep', no
need for them.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
 arch/x86/kvm/paging_tmpl.h |   62 +++++++++++++++++--------------------------
 1 files changed, 25 insertions(+), 37 deletions(-)

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 05bbbf6..ff3d0c0 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -326,12 +326,10 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 {
 	unsigned access = gw->pt_access;
 	struct kvm_mmu_page *uninitialized_var(sp);
-	u64 *sptep = NULL;
-	int uninitialized_var(level);
 	bool dirty = is_dirty_gpte(gw->ptes[gw->level - 1]);
 	int top_level;
 	unsigned direct_access;
-	struct kvm_shadow_walk_iterator iterator;
+	struct kvm_shadow_walk_iterator uninitialized_var(it);
 
 	if (!is_present_gpte(gw->ptes[gw->level - 1]))
 		return NULL;
@@ -349,25 +347,21 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 	 * changed from now on) or it is invalid (in which case, we don't
 	 * really care if it changes underneath us after this point).
 	 */
-	if (!FNAME(validate_indirect_spte)(vcpu, sptep, sp,
-					   gw, top_level))
+	if (!FNAME(validate_indirect_spte)(vcpu, it.sptep, sp, gw, top_level))
 		goto out_error;
 
-	for (shadow_walk_init(&iterator, vcpu, addr);
-	     shadow_walk_okay(&iterator) && iterator.level > gw->level;
-	     shadow_walk_next(&iterator)) {
+	for (shadow_walk_init(&it, vcpu, addr);
+	     shadow_walk_okay(&it) && it.level > gw->level;
+	     shadow_walk_next(&it)) {
 		gfn_t table_gfn;
 		bool new_page = false;
 
-		level = iterator.level;
-		sptep = iterator.sptep;
-
-		drop_large_spte(vcpu, sptep);
+		drop_large_spte(vcpu, it.sptep);
 
-		if (!is_shadow_present_pte(*sptep)) {
-			table_gfn = gw->table_gfn[level - 2];
-			sp = kvm_mmu_get_page(vcpu, table_gfn, addr, level-1,
-					      false, access, sptep);
+		if (!is_shadow_present_pte(*it.sptep)) {
+			table_gfn = gw->table_gfn[it.level - 2];
+			sp = kvm_mmu_get_page(vcpu, table_gfn, addr, it.level-1,
+					      false, access, it.sptep);
 			new_page = true;
 		}
 
@@ -375,44 +369,38 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 		 * Verify that the gpte in the page we've just write
 		 * protected is still there.
 		 */
-		if (!FNAME(validate_indirect_spte)(vcpu, sptep, sp,
-						   gw, level - 1))
+		if (!FNAME(validate_indirect_spte)(vcpu, it.sptep, sp,
+						   gw, it.level - 1))
 			goto out_error;
 
 		if (new_page)
-			link_shadow_page(sptep, sp);
+			link_shadow_page(it.sptep, sp);
 	}
 
 	for (;
-	     shadow_walk_okay(&iterator) && iterator.level > hlevel;
-	     shadow_walk_next(&iterator)) {
+	     shadow_walk_okay(&it) && it.level > hlevel;
+	     shadow_walk_next(&it)) {
 		gfn_t direct_gfn;
 
-		level = iterator.level;
-		sptep = iterator.sptep;
+		drop_large_spte(vcpu, it.sptep);
 
-		drop_large_spte(vcpu, sptep);
-
-		if (is_shadow_present_pte(*sptep))
+		if (is_shadow_present_pte(*it.sptep))
 			continue;
 
-		validate_direct_spte(vcpu, sptep, direct_access);
+		validate_direct_spte(vcpu, it.sptep, direct_access);
 
-		direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(level) - 1);
+		direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
 
-		sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, level-1,
-				      true, direct_access, sptep);
-		link_shadow_page(sptep, sp);
+		sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1,
+				      true, direct_access, it.sptep);
+		link_shadow_page(it.sptep, sp);
 	}
 
-	sptep = iterator.sptep;
-	level = iterator.level;
-
-	mmu_set_spte(vcpu, sptep, access, gw->pte_access & access,
-		     user_fault, write_fault, dirty, ptwrite, level,
+	mmu_set_spte(vcpu, it.sptep, access, gw->pte_access & access,
+		     user_fault, write_fault, dirty, ptwrite, it.level,
 		     gw->gfn, pfn, false, true);
 
-	return sptep;
+	return it.sptep;
 
 out_error:
 	kvm_release_pfn_clean(pfn);
-- 
1.7.1