Xen devel - Jun 2011 - [PATCH] xen: only track the linear framebuffer

Xen can only do dirty bit tracking for one memory region, so we should
explicitly avoid trying to track anything but the vga vram region.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

diff --git a/xen-all.c b/xen-all.c
index 9a5c3ec..fa1d2e1 100644
--- a/xen-all.c
+++ b/xen-all.c
@@ -214,6 +214,7 @@ static int xen_add_to_physmap(XenIOState *state,
     unsigned long i = 0;
     int rc = 0;
     XenPhysmap *physmap = NULL;
+    RAMBlock *block;
 
     if (get_physmapping(state, start_addr, size)) {
         return 0;
@@ -221,7 +222,19 @@ static int xen_add_to_physmap(XenIOState *state,
     if (size <= 0) {
         return -1;
     }
+    /* Xen can only handle a single dirty log region for now and we want
+     * the linear framebuffer to be that region.
+     * Avoid tracking any regions that is not videoram and avoid tracking
+     * the legacy vga region. */
+    QLIST_FOREACH(block, &ram_list.blocks, next) {
+        if (!strcmp(block->idstr, "vga.vram") &&
block->offset == phys_offset
+                && start_addr > 0xbffff) {
+            goto go_physmap;
+        }
+    }
+    return -1;
 
+go_physmap:
     DPRINTF("mapping vram to %llx - %llx, from %llx\n", start_addr,
start_addr + size, phys_offset);
     for (i = 0; i < size >> TARGET_PAGE_BITS; i++) {
         unsigned long idx = (phys_offset >> TARGET_PAGE_BITS) + i;

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel