feat: rewrite msr_reader in python

Rewrite `msr_reader.sh` script in python to speed up manual validation of
msr baselines.
Bash script run in ~1 minute. python version runs in 0.35 seconds.

Signed-off-by: Egor Lazarchuk <[email protected]>

Author: ShadowCurse

tests/data/msr/msr_reader.py

@@ -0,0 +1,30 @@
+# Copyright 2025 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+# Helper script used to read MSR values from ranges known to contain MSRs.
+
+import os
+
+msr_fd = open("/dev/cpu/0/msr", "r")
+
+def print_msr(msr: int):
+    try:
+        msr_bytes = os.pread(msr_fd.fileno(), 8, msr)
+        msr_value = int.from_bytes(msr_bytes, byteorder="little")
+        print(f"{msr:#x},{msr_value:#x}")
+    except:
+        pass
+
+print("MSR_ADDR,VALUE")
+for msr in range(0,          0xFFF + 1):      print_msr(msr);
+for msr in range(0x10000,    0x10FFF + 1):    print_msr(msr);
+for msr in range(0xC0000000, 0xC0011030 + 1): print_msr(msr);
+
+print_msr(0x400000000);
+print_msr(0x2000000000);
+print_msr(0x4000000000);
+print_msr(0x8000000000);
+print_msr(0x1000000000000);
+print_msr(0x3c000000000000);
+print_msr(0x80000000000000);
+print_msr(0x40000000000000);

tests/integration_tests/functional/test_cpu_features_x86_64.py

@@ -300,8 +300,12 @@ def test_cpu_rdmsr(
     vm.basic_config(vcpu_count=vcpus, mem_size_mib=guest_mem_mib)
     vm.set_cpu_template(cpu_template_any)
     vm.start()
-    vm.ssh.scp_put(msr_reader_bin, "/tmp/msr_reader")
-    _, stdout, stderr = vm.ssh.run("/tmp/msr_reader")
+    # vm.ssh.scp_put(msr_reader_bin, "/tmp/msr_reader")
+    # _, stdout, stderr = vm.ssh.run("/tmp/msr_reader")
+
+    vm.ssh.scp_put(msr_reader_bin, "/tmp/msr_reader.py")
+    _, stdout, stderr = vm.ssh.run("python3 /tmp/msr_reader.py")
+
     assert stderr == ""
 
     # Load results read from the microvm