diff --git a/win_dump.c b/win_dump.c
index b15c191ad7..e10a7831c2 100644
--- a/win_dump.c
+++ b/win_dump.c
@@ -30,28 +30,32 @@ static size_t write_run(WinDumpPhyMemRun64 *run, int fd, Error **errp)
     void *buf;
     uint64_t addr = run->BasePage << TARGET_PAGE_BITS;
     uint64_t size = run->PageCount << TARGET_PAGE_BITS;
-    uint64_t len = size;
+    uint64_t len, l;
+    size_t total = 0;
 
-    buf = cpu_physical_memory_map(addr, &len, false);
-    if (!buf) {
-        error_setg(errp, "win-dump: failed to map run");
-        return 0;
-    }
-    if (len != size) {
-        error_setg(errp, "win-dump: failed to map entire run");
-        len = 0;
-        goto out_unmap;
+    while (size) {
+        len = size;
+
+        buf = cpu_physical_memory_map(addr, &len, false);
+        if (!buf) {
+            error_setg(errp, "win-dump: failed to map physical range"
+                             " 0x%016" PRIx64 "-0x%016" PRIx64, addr, addr + size - 1);
+            return 0;
+        }
+
+        l = qemu_write_full(fd, buf, len);
+        cpu_physical_memory_unmap(buf, addr, false, len);
+        if (l != len) {
+            error_setg(errp, QERR_IO_ERROR);
+            return 0;
+        }
+
+        addr += l;
+        size -= l;
+        total += l;
     }
 
-    len = qemu_write_full(fd, buf, len);
-    if (len != size) {
-        error_setg(errp, QERR_IO_ERROR);
-    }
-
-out_unmap:
-    cpu_physical_memory_unmap(buf, addr, false, len);
-
-    return len;
+    return total;
 }
 
 static void write_runs(DumpState *s, WinDumpHeader64 *h, Error **errp)