KVM: Add tdx_memory_confident case

KVM/qemu/tdx_memory_confident.cfg

@@ -0,0 +1,13 @@
+- tdx_memory_confident:
+    type = tdx_memory_confident
+    virt_test_type = qemu
+    # Too large memory will lead to python asyncio exception.
+    mem = 1024
+    machine_type_extra_params = "kernel-irqchip=split"
+    # Don't create/remove guest images
+    start_vm = no
+    # Stop VM after testing
+    kill_vm = yes
+    auto_cpu_model = "no"
+    cpu_model = host
+    dump_memory_path = "/tmp/memory-dump"

KVM/qemu/tests/tdx_memory_confident.py

@@ -0,0 +1,78 @@
+#!/usr/bin/python3
+
+# SPDX-License-Identifier: GPL-2.0-only
+# Copyright (c) 2026 Intel Corporation
+
+# Author: Kai Zhang <kai.zhang@intel.com>
+#
+# History:  Apr. 2026 - Kai Zhang - creation
+
+
+from provider import dmesg_router  # pylint: disable=unused-import
+from avocado.utils import process
+from virttest import error_context, env_process
+from provider.cpu_utils import check_cpu_flags
+
+
+def check_confident(vm, session, dump_memory_path):
+    session.cmd("mkdir -pv /tmp/mnt/")
+    session.cmd("mount tmpfs /tmp/mnt/ -t tmpfs -o size=32M")
+    vm.copy_files_to("/tmp/secret", "/tmp/mnt/")
+
+    # paging = "off"
+    process.system("rm -f %s && touch %s" % (dump_memory_path, dump_memory_path), ignore_status=True)
+    vm.monitor.human_monitor_cmd("dump-guest-memory %s" % dump_memory_path)
+    with open(dump_memory_path, '+rb') as f:
+        content = f.read().decode('utf-8', errors='ignore')
+        if "TDX Test" not in content:
+            return False
+    return True
+
+
+@error_context.context_aware
+def run(test, params, env):
+    """
+    TDX memory confidentiality test:
+    1. Boot VM
+    2. Write something in a file on host and copy it to tmpfs on VM
+    3. Dump memory from VM, expect the secret could be found
+    4. Boot TDVM
+    5. Write something in a file on host and copy it to tmpfs on TDVM
+    6. Dump memory from TDVM, expect the secret could not be found
+
+    :param test: QEMU test object
+    :param params: Dictionary with the test parameters
+    :param env: Dictionary with test environment.
+
+    This test will create both legacy VM and tdx-enabled VM.
+    """
+    with open("/tmp/secret", "w") as secret_file:
+        secret_file.write("TDX Test: This is a test\n")
+    dump_memory_path = params.get("dump_memory_path")
+    params["start_vm"] = "yes"
+    env_process.preprocess_vm(test, params, env, params["main_vm"])
+    vm = env.get_vm(params["main_vm"])
+    vm.verify_alive()
+    timeout = params.get_numeric("login_timeout", 240)
+    session = vm.wait_for_login(timeout=timeout)
+    copy_result = check_confident(vm, session, dump_memory_path)
+    if not copy_result:
+        test.fail("Secret is not found in memory dump of legacy VM")
+    session.close()
+    vm.destroy()
+
+    params["vm_secure_guest_type"] = "tdx"
+    params["guest_flags"] = "tdx_guest"
+    env_process.preprocess_vm(test, params, env, params["main_vm"])
+    vm = env.get_vm(params["main_vm"])
+    vm.verify_alive()
+    timeout = params.get_numeric("login_timeout", 240)
+    session = vm.wait_for_login(timeout=timeout)
+    flags = params["guest_flags"]
+    check_cpu_flags(params, flags, test, session)
+    copy_result = check_confident(vm, session, dump_memory_path)
+    if copy_result:
+        test.fail("Secret is found in memory dump of TDVM")
+    process.system("rm -f /tmp/secret %s" % params["dump_memory_path"], ignore_status=True)
+    # TDVM will be destroyed as `kill_vm = yes` is set in cfg, no need to destroy it here.
+    session.close()