CPUPhysMemoryClient: Pass guest physical address not region offset

When we're trying to get a newly registered phys memory client updated
with the current page mappings, we end up passing the region offset
(a ram_addr_t) as the start address rather than the actual guest
physical memory address (target_phys_addr_t).  If your guest has less
than 3.5G of memory, these are coincidentally the same thing.  If
there's more, the region offset for the memory above 4G starts over
at 0, so the set_memory client will overwrite it's lower memory entries.

Instead, keep track of the guest phsyical address as we're walking the
tables and pass that to the set_memory client.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/exec.c b/exec.c
index 9823e355f7d5f4539e6f933540fe1b495801e7a5..0c773a8ad9aa8d6d80136f052381e57cb909691a 100644 (file)
--- a/exec.c
+++ b/exec.c
@@ -1743,8 +1743,14 @@ static int cpu_notify_migration_log(int enable)
     return 0;
 }
 
+/* The l1_phys_map provides the upper P_L1_BITs of the guest physical
+ * address.  Each intermediate table provides the next L2_BITs of guest
+ * physical address space.  The number of levels vary based on host and
+ * guest configuration, making it efficient to build the final guest
+ * physical address by seeding the L1 offset and shifting and adding in
+ * each L2 offset as we recurse through them. */
 static void phys_page_for_each_1(CPUPhysMemoryClient *client,
-                                 int level, void **lp)
+                                 int level, void **lp, target_phys_addr_t addr)
 {
     int i;
 
@@ -1753,16 +1759,18 @@ static void phys_page_for_each_1(CPUPhysMemoryClient *client,
     }
     if (level == 0) {
         PhysPageDesc *pd = *lp;
+        addr <<= L2_BITS + TARGET_PAGE_BITS;
         for (i = 0; i < L2_SIZE; ++i) {
             if (pd[i].phys_offset != IO_MEM_UNASSIGNED) {
-                client->set_memory(client, pd[i].region_offset,
+                client->set_memory(client, addr | i << TARGET_PAGE_BITS,
                                    TARGET_PAGE_SIZE, pd[i].phys_offset, false);
             }
         }
     } else {
         void **pp = *lp;
         for (i = 0; i < L2_SIZE; ++i) {
-            phys_page_for_each_1(client, level - 1, pp + i);
+            phys_page_for_each_1(client, level - 1, pp + i,
+                                 (addr << L2_BITS) | i);
         }
     }
 }
@@ -1772,7 +1780,7 @@ static void phys_page_for_each(CPUPhysMemoryClient *client)
     int i;
     for (i = 0; i < P_L1_SIZE; ++i) {
         phys_page_for_each_1(client, P_L1_SHIFT / L2_BITS - 1,
-                             l1_phys_map + i);
+                             l1_phys_map + i, i);
     }
 }