migration/postcopy: discard_length must not be 0

[mirror_qemu.git] / exec.c

diff --git a/exec.c b/exec.c
index 50ea9c5aaa8f2ad732793b91625194f781e8e24f..3e78de3b8f8bb1914811a796537790bc4df8ad2f 100644 (file)
--- a/exec.c
+++ b/exec.c
@@ -1358,6 +1358,8 @@ bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
     DirtyMemoryBlocks *blocks;
     unsigned long end, page;
     bool dirty = false;
+    RAMBlock *ramblock;
+    uint64_t mr_offset, mr_size;
 
     if (length == 0) {
         return false;
@@ -1369,6 +1371,10 @@ bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
     rcu_read_lock();
 
     blocks = atomic_rcu_read(&ram_list.dirty_memory[client]);
+    ramblock = qemu_get_ram_block(start);
+    /* Range sanity check on the ramblock */
+    assert(start >= ramblock->offset &&
+           start + length <= ramblock->offset + ramblock->used_length);
 
     while (page < end) {
         unsigned long idx = page / DIRTY_MEMORY_BLOCK_SIZE;
@@ -1380,6 +1386,10 @@ bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
         page += num;
     }
 
+    mr_offset = (ram_addr_t)(page << TARGET_PAGE_BITS) - ramblock->offset;
+    mr_size = (end - page) << TARGET_PAGE_BITS;
+    memory_region_clear_dirty_bitmap(ramblock->mr, mr_offset, mr_size);
+
     rcu_read_unlock();
 
     if (dirty && tcg_enabled()) {
@@ -1390,9 +1400,10 @@ bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start,
 }
 
 DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
-     (ram_addr_t start, ram_addr_t length, unsigned client)
+    (MemoryRegion *mr, hwaddr offset, hwaddr length, unsigned client)
 {
     DirtyMemoryBlocks *blocks;
+    ram_addr_t start = memory_region_get_ram_addr(mr) + offset;
     unsigned long align = 1UL << (TARGET_PAGE_BITS + BITS_PER_LEVEL);
     ram_addr_t first = QEMU_ALIGN_DOWN(start, align);
     ram_addr_t last  = QEMU_ALIGN_UP(start + length, align);
@@ -1434,6 +1445,8 @@ DirtyBitmapSnapshot *cpu_physical_memory_snapshot_and_clear_dirty
         tlb_reset_dirty_range_all(start, length);
     }
 
+    memory_region_clear_dirty_bitmap(mr, offset, length);
+
     return snap;
 }