KVM: MMU: Introduce and use gpte_to_gfn()

Instead of repretitively open-coding this.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

drivers/kvm/paging_tmpl.h

@@ -52,6 +52,9 @@
 	#error Invalid PTTYPE value
 #endif
 
+#define gpte_to_gfn FNAME(gpte_to_gfn)
+#define gpte_to_gfn_pde FNAME(gpte_to_gfn_pde)
+
 /*
  * The guest_walker structure emulates the behavior of the hardware page
  * table walker.
@@ -65,6 +68,16 @@ struct guest_walker {
 	u32 error_code;
 };
 
+static gfn_t gpte_to_gfn(pt_element_t gpte)
+{
+	return (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
+}
+
+static gfn_t gpte_to_gfn_pde(pt_element_t gpte)
+{
+	return (gpte & PT_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
+}
+
 /*
  * Fetch a guest pte for a guest virtual address
  */
@@ -96,7 +109,7 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
 	for (;;) {
 		index = PT_INDEX(addr, walker->level);
 
-		table_gfn = (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
+		table_gfn = gpte_to_gfn(pte);
 		pte_gpa = table_gfn << PAGE_SHIFT;
 		pte_gpa += index * sizeof(pt_element_t);
 		walker->table_gfn[walker->level - 1] = table_gfn;
@@ -127,15 +140,14 @@ static int FNAME(walk_addr)(struct guest_walker *walker,
 		}
 
 		if (walker->level == PT_PAGE_TABLE_LEVEL) {
-			walker->gfn = (pte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
+			walker->gfn = gpte_to_gfn(pte);
 			break;
 		}
 
 		if (walker->level == PT_DIRECTORY_LEVEL
 		    && (pte & PT_PAGE_SIZE_MASK)
 		    && (PTTYPE == 64 || is_pse(vcpu))) {
-			walker->gfn = (pte & PT_DIR_BASE_ADDR_MASK)
-				>> PAGE_SHIFT;
+			walker->gfn = gpte_to_gfn_pde(pte);
 			walker->gfn += PT_INDEX(addr, PT_PAGE_TABLE_LEVEL);
 			break;
 		}
@@ -296,8 +308,7 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
 		return;
 	pgprintk("%s: gpte %llx spte %p\n", __FUNCTION__, (u64)gpte, spte);
 	FNAME(set_pte)(vcpu, gpte, spte, PT_USER_MASK | PT_WRITABLE_MASK, 0,
-		       0, NULL, NULL,
-		       (gpte & PT_BASE_ADDR_MASK) >> PAGE_SHIFT);
+		       0, NULL, NULL, gpte_to_gfn(gpte));
 }
 
 static void FNAME(set_pde)(struct kvm_vcpu *vcpu, pt_element_t gpde,
@@ -370,8 +381,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
 			hugepage_access >>= PT_WRITABLE_SHIFT;
 			if (walker->pte & PT64_NX_MASK)
 				hugepage_access |= (1 << 2);
-			table_gfn = (walker->pte & PT_BASE_ADDR_MASK)
-				>> PAGE_SHIFT;
+			table_gfn = gpte_to_gfn(walker->pte);
 		} else {
 			metaphysical = 0;
 			table_gfn = walker->table_gfn[level - 2];
@@ -519,3 +529,5 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
 #undef PT_DIR_BASE_ADDR_MASK
 #undef PT_LEVEL_BITS
 #undef PT_MAX_FULL_LEVELS
+#undef gpte_to_gfn
+#undef gpte_to_gfn_pde