new package: msr-safe (spack#46289)

This includes a test_linux699 variant which "activates" a version
that pulls from a repository other than the official repository.
This version is required to work with Linux kernel version
6.9.9 or later. Future official `msr-safe` versions are expected
to support later Linux kernel versions.

var/spack/repos/builtin/packages/msr-safe/package.py

@@ -0,0 +1,61 @@
+# Copyright 2013-2024 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack.package import *
+
+
+class MsrSafe(MakefilePackage):
+    """msr_safe provides controlled userspace access to model-specific registers (MSRs).
+    It allows system administrators to give register-level read access and bit-level write
+    access to trusted users in production environments. This access is useful where kernel
+    drivers have not caught up with new processor features, or performance constraints
+    requires batch access across dozens or hundreds of registers."""
+
+    homepage = "https://github.com/LLNL/msr-safe"
+    url = "https://github.com/LLNL/msr-safe/archive/refs/tags/v1.7.0.tar.gz"
+
+    maintainers("kyotsukete", "rountree")
+
+    license("GPL-2.0-only", checked_by="kyotsukete")
+
+    variant(
+        "test_linux699",
+        default=False,
+        description="This variant is for testing against Linux kernel 6.9.9",
+    )
+
+    requires("@0.0.0_linux6.9.9", when="+test_linux699")
+    conflicts("@0.0.0_linux6.9.9", when="~test_linux699")
+
+    # Version 0.0.0_linux6.9.9 is based on msr-safe@1.7.0 and solves for conflicts between 1.7.0
+    # and the Linux kernel version 6.9.9.
+    version(
+        "0.0.0_linux6.9.9",
+        sha256="2b68670eda4467eaa9ddd7340522ab2000cf9d16d083607f9c481650ea1a2fc9",
+        url="https://github.com/rountree/msr-safe/archive/refs/heads/linux-6.9.9-cleanup.zip",
+    )
+    version("1.7.0", sha256="bdf4f96bde92a23dc3a98716611ebbe7d302005305adf6a368cb25da9c8a609a")
+    version("1.6.0", sha256="defe9d12e2cdbcb1a9aa29bb09376d4156c3dbbeb7afc33315ca4b0b6859f5bb")
+    version("1.5.0", sha256="e91bac281339bcb0d119a74d68a73eafb5944fd933a893e0e3209576b4c6f233")
+    version("1.4.0", sha256="3e5a913e73978c9ce15ec5d2bf1a4583e9e5c30e4e75da0f76d9a7a6153398c0")
+    version("1.3.0", sha256="718dcc78272b45ffddf520078e7e54b0b6ce272f1ef0376de009a133149982a0")
+    version("1.2.0", sha256="d3c2e5280f94d65866f82a36fea50562dc3eaccbcaa81438562caaf35989d8e8")
+    version("1.1.0", sha256="5b723e9d360e15f3ed854a84de7430b2b77be1eb1515db03c66456db43684a83")
+    version("1.0.2", sha256="9511d021ab6510195e8cc3b0353a0ac414ab6965a188f47fbb8581f9156a970e")
+
+    depends_on("linux-external-modules")
+
+    @property
+    def build_targets(self):
+        return [
+            "-C",
+            f"{self.spec['linux-external-modules'].prefix}",
+            f"M={self.build_directory}",
+            "modules",
+        ]
+
+    @property
+    def install_targets(self):
+        return [f"DESTDIR={self.prefix}", "spack-install"]