[Qemu-devel] [PATCH 06/22] framebuffer: check memory_region_is_logging

[Paolo Bonzini]

framebuffer.c expects DIRTY_MEMORY_VGA logging to be always on, but that
will not be the case soon.  Because framebuffer.c computes the memory
region on the fly for every update (with memory_region_find), it cannot
enable/disable logging by itself.

Instead, always treat updates as invalidations if dirty logging is
not enabled, assuming that the board will enable logging on the
RAM region that includes the framebuffer.

To simplify the code, replace memory_region_get_dirty with
memory_region_test_and_clear_dirty.  Then memory_region_reset_dirty
is only needed in the invalidate case.

Signed-off-by: Paolo Bonzini <address@hidden>
---
 hw/display/framebuffer.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/hw/display/framebuffer.c b/hw/display/framebuffer.c
index 4546e42..49fe204 100644
--- a/hw/display/framebuffer.c
+++ b/hw/display/framebuffer.c
@@ -62,7 +62,16 @@ void framebuffer_update_display(
     assert(mem);
     assert(mem_section.offset_within_address_space == base);
 
-    memory_region_sync_dirty_bitmap(mem);
+    if (memory_region_is_logging(mem) & (1 << DIRTY_MEMORY_VGA)) {
+         memory_region_sync_dirty_bitmap(mem);
+         if (invalidate) {
+             memory_region_reset_dirty(mem, mem_section.offset_within_region,
+                                       src_len, DIRTY_MEMORY_VGA);
+         }
+    } else {
+        invalidate = true;
+    }
+
     src_base = cpu_physical_memory_map(base, &src_len, 0);
     /* If we can't map the framebuffer then bail.  We could try harder,
        but it's not really worth it as dirty flag tracking will probably
@@ -88,9 +97,13 @@ void framebuffer_update_display(
     dest += i * dest_row_pitch;
 
     for (; i < rows; i++) {
-        dirty = memory_region_get_dirty(mem, addr, src_width,
-                                             DIRTY_MEMORY_VGA);
-        if (dirty || invalidate) {
+        if (invalidate) {
+            dirty = true;
+        } else {
+            dirty = memory_region_test_and_clear_dirty(mem, addr, src_width,
+                                                       DIRTY_MEMORY_VGA);
+        }
+        if (dirty) {
             fn(opaque, dest, src, cols, dest_col_pitch);
             if (first == -1)
                 first = i;
@@ -104,8 +117,6 @@ void framebuffer_update_display(
     if (first < 0) {
         goto out;
     }
-    memory_region_reset_dirty(mem, mem_section.offset_within_region, src_len,
-                              DIRTY_MEMORY_VGA);
     *first_row = first;
     *last_row = last;
 out:
-- 
2.3.3