test(snapshot): verify entropy source after cross-kernel restore

Check that /dev/hwrng is functional after restoring a snapshot on a
different host kernel version.

Signed-off-by: Jack Thomson <jackabt@amazon.com>

Author: JackThomson2

tests/integration_tests/functional/test_snapshot_phase1.py

@@ -58,6 +58,8 @@ def test_snapshot_phase1(
     configure_mmds(vm, ["eth3"], version="V2")
     # Add a memory balloon.
     vm.api.balloon.put(amount_mib=0, deflate_on_oom=True, stats_polling_interval_s=1)
+    # Add an entropy device.
+    vm.api.entropy.put()
 
     vm.start()
 

tests/integration_tests/functional/test_snapshot_restore_cross_kernel.py

@@ -11,6 +11,7 @@
 
 from framework.defs import FC_WORKSPACE_DIR
 from framework.utils import (
+    check_entropy,
     generate_mmds_get_request,
     generate_mmds_session_token,
     guest_run_fio_iteration,
@@ -125,4 +126,7 @@ def test_snap_restore_from_artifacts(
     logger.info("Testing block device via fio...")
     guest_run_fio_iteration(vm.ssh, 0)
 
+    logger.info("Testing entropy...")
+    check_entropy(vm.ssh)
+
     vm.kill()