From f642465dc4ef0f8fa756c765293b920b05c2ce5b Mon Sep 17 00:00:00 2001
From: Fam Zheng <famz@redhat.com>
Date: Wed, 21 Feb 2018 21:07:56 -0500
Subject: [PATCH] exec: Factor out section_covers_addr

This will be shared by the next patch.

Also add a comment explaining the unobvious condition on "size.hi".

Backports commit 29cb533d8cbff1330717619780c2f1dfe764e003 from qemu
---
 qemu/exec.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/qemu/exec.c b/qemu/exec.c
index a31d97dd..8a0e26e0 100644
--- a/qemu/exec.c
+++ b/qemu/exec.c
@@ -260,6 +260,17 @@ static void phys_page_compact_all(AddressSpaceDispatch *d, int nodes_nb)
     }
 }
 
+static inline bool section_covers_addr(const MemoryRegionSection *section,
+                                       hwaddr addr)
+{
+    /* Memory topology clips a memory region to [0, 2^64); size.hi > 0 means
+     * the section must cover the entire address space.
+     */
+    return section->size.hi ||
+           range_covers_byte(section->offset_within_address_space,
+                             section->size.lo, addr);
+}
+
 static MemoryRegionSection *phys_page_find(PhysPageEntry lp, hwaddr addr,
         Node *nodes, MemoryRegionSection *sections)
 {
@@ -275,9 +286,7 @@ static MemoryRegionSection *phys_page_find(PhysPageEntry lp, hwaddr addr,
         lp = p[(index >> (i * P_L2_BITS)) & (P_L2_SIZE - 1)];
     }
 
-    if (sections[lp.ptr].size.hi ||
-            range_covers_byte(sections[lp.ptr].offset_within_address_space,
-                sections[lp.ptr].size.lo, addr)) {
+    if (section_covers_addr(&sections[lp.ptr], addr)) {
         return &sections[lp.ptr];
     } else {
         return &sections[PHYS_SECTION_UNASSIGNED];