[Qemu-devel] [PATCH 34/60] memory: fix rendering of a region obscured by another

[Michael Tokarev]

From: Avi Kivity <address@hidden>

The memory core drops regions that are hidden by another region (for example,
during BAR sizing), but it doesn't do so correctly if the lower address of the
existing range is below the lower address of the new range.

Example (qemu-system-mips -M malta -kernel vmlinux-2.6.32-5-4kc-malta
         -append "console=ttyS0"  -nographic -vga cirrus):

Existing range: 10000000-107fffff
New range:      100a0000-100bffff

Correct behaviour: drop new range
Incorrect behaviour: add new range

Fix by taking this case into account (previously we only considered
equal lower boundaries).

Tested-by: Aurelien Jarno <address@hidden>
Signed-off-by: Avi Kivity <address@hidden>
Signed-off-by: Anthony Liguori <address@hidden>
(cherry picked from commit d26a8caea3f160782841efb87b5e8bea606b512b)

Signed-off-by: Michael Tokarev <address@hidden>
---
 memory.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/memory.c b/memory.c
index f039464..d8654fc 100644
--- a/memory.c
+++ b/memory.c
@@ -538,12 +538,12 @@ static void render_memory_region(FlatView *view,
             offset_in_region += int128_get64(now);
             int128_subfrom(&remain, now);
         }
-        if (int128_eq(base, view->ranges[i].addr.start)) {
-            now = int128_min(remain, view->ranges[i].addr.size);
-            int128_addto(&base, now);
-            offset_in_region += int128_get64(now);
-            int128_subfrom(&remain, now);
-        }
+        now = int128_sub(int128_min(int128_add(base, remain),
+                                    addrrange_end(view->ranges[i].addr)),
+                         base);
+        int128_addto(&base, now);
+        offset_in_region += int128_get64(now);
+        int128_subfrom(&remain, now);
     }
     if (int128_nz(remain)) {
         fr.mr = mr;
-- 
1.7.10.4