support/testing: add test for msr-tools

Add a simple test to verify that msr-tools are working.

The test needs to build a custom x86_64 kernel with support for CPUID and
MSR.

As the TSC_AUX MSR is emulated on qemu we can use it to test that a value
written with wrmsr can indeed be read back with rdmsr.

Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

DEVELOPERS

@@ -2917,6 +2917,7 @@ F:	configs/uevm5432_defconfig
 F:	package/i7z/
 F:	package/msr-tools/
 F:	package/pixz/
+F:	support/testing/tests/package/test_msr_tools*
 F:	support/testing/tests/package/test_pixz.py
 
 N:	Vinicius Tinti <viniciustinti@gmail.com>

support/testing/tests/package/test_msr_tools.py

@@ -0,0 +1,50 @@
+import os
+
+import infra.basetest
+
+
+class TestMsrTools(infra.basetest.BRTest):
+    config = \
+        """
+        BR2_x86_64=y
+        BR2_x86_corei7=y
+        BR2_TOOLCHAIN_EXTERNAL=y
+        BR2_LINUX_KERNEL=y
+        BR2_LINUX_KERNEL_CUSTOM_VERSION=y
+        BR2_LINUX_KERNEL_CUSTOM_VERSION_VALUE="5.15.55"
+        BR2_LINUX_KERNEL_USE_CUSTOM_CONFIG=y
+        BR2_LINUX_KERNEL_CUSTOM_CONFIG_FILE="board/qemu/x86_64/linux.config"
+        BR2_LINUX_KERNEL_CONFIG_FRAGMENT_FILES="{}"
+        BR2_LINUX_KERNEL_NEEDS_HOST_LIBELF=y
+        BR2_PACKAGE_MSR_TOOLS=y
+        BR2_TARGET_ROOTFS_CPIO=y
+        # BR2_TARGET_ROOTFS_TAR is not set
+        """.format(
+              infra.filepath("tests/package/test_msr_tools/linux.config"))
+
+    def test_run(self):
+        kernel = os.path.join(self.builddir, "images", "bzImage")
+        cpio_file = os.path.join(self.builddir, "images", "rootfs.cpio")
+        self.emulator.boot(
+            arch="x86_64",
+            kernel=kernel, kernel_cmdline=["console=ttyS0"],
+            options=["-cpu", "Nehalem", "-m", "320", "-initrd", cpio_file]
+        )
+        self.emulator.login()
+
+        # CPU ID.
+        cmd = "cpuid"
+        self.assertRunOk(cmd)
+
+        # Write MSR.
+        # We write to TSC_AUX.
+        cmd = "wrmsr 0xc0000103 0x1234567812345678"
+        self.assertRunOk(cmd)
+
+        # Read MSR.
+        # We read back the TSC_AUX and we verify that we read back the correct
+        # value.
+        cmd = "rdmsr 0xc0000103"
+        output, exit_code = self.emulator.run(cmd)
+        self.assertEqual(exit_code, 0)
+        self.assertEqual(output[0], "1234567812345678")

support/testing/tests/package/test_msr_tools/linux.config

@@ -0,0 +1,2 @@
+CONFIG_X86_CPUID=y
+CONFIG_X86_MSR=y