Update cmd of read_rng_cmd

Signed-off-by: NSuqin Huang <shuang@redhat.com>

qemu/tests/cfg/rng_read_longtime.cfg

@@ -2,14 +2,14 @@
     type = rng_bat
     kill_vm = yes
     virt_test_type = qemu
-    read_rng_timeout = 3600
+    read_rng_timeout = 1200
     no no_virtio_rng
     test_duration = 36000
     Windows:
         # Please update path of rng_dll_register_cmd to right path which included you driver
         #rng_dll_register_cmd = if not exist "C:\Windows\system32\viorngum.dll" copy PATH:\INCLUDEDRIVER\viorngum.dll C:\Windows\system32\ /y &&"
         session_cmd_timeout = 240
-        read_rng_cmd = for /l %i in (1, 1, 30) do "WIN_UTILS:\random_%PROCESSOR_ARCHITECTURE%.exe"
+        read_rng_cmd = for /l %i in (1, 1, 1000) do "WIN_UTILS:\random_%PROCESSOR_ARCHITECTURE%.exe"
         driver_name = "viorng"
         rng_data_rex = "0x\w"
         driver_id_pattern = "(.*?):.*?VirtIO RNG Device"
@@ -21,7 +21,7 @@
             driver_check_cmd = "WIN_UTILS:\devcon\wnet_amd64\devcon.exe status @DRIVER_ID"
     Linux:
         session_cmd_timeout = 360
-        read_rng_cmd = "dd if=/dev/random bs=4 count=100 2>/dev/null|hexdump"
+        read_rng_cmd = "dd if=/dev/random bs=4 count=1000 2>/dev/null|hexdump"
         driver_verifier_cmd = "cat /sys/devices/virtual/misc/hw_random/rng_current"
         driver_name = virtio
         rng_data_rex = "\w+"