From 9f38cec485132ed76e67994d5505b977fa195f13 Mon Sep 17 00:00:00 2001
From: Oliver Anderson <oliver.anderson@cyberus-technology.de>
Date: Fri, 20 Mar 2026 16:21:02 +0100
Subject: [PATCH] arch: Serializable CPUID parameters

We introduce a type representing CPUID parameters that will be utilized
by the CPU profiles.

We place this new type in a module that will be further populated with
types related to adjusting CPUID entries based on the CPU profile
in a follow up commit.

Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de>
On-behalf-of: SAP oliver.anderson@sap.com
---
 .../x86_64/cpu_profile/cpuid_adjustments.rs   | 66 +++++++++++++++++++
 arch/src/x86_64/cpu_profile/mod.rs            |  6 ++
 arch/src/x86_64/mod.rs                        |  1 +
 3 files changed, 73 insertions(+)
 create mode 100644 arch/src/x86_64/cpu_profile/cpuid_adjustments.rs
 create mode 100644 arch/src/x86_64/cpu_profile/mod.rs

diff --git a/arch/src/x86_64/cpu_profile/cpuid_adjustments.rs b/arch/src/x86_64/cpu_profile/cpuid_adjustments.rs
new file mode 100644
index 000000000..10ae1bb61
--- /dev/null
+++ b/arch/src/x86_64/cpu_profile/cpuid_adjustments.rs
@@ -0,0 +1,66 @@
+// Copyright © 2026 Cyberus Technology GmbH
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+//! This module contains types associated with adjusting CPUID entries according
+//! to a selected CPU profile.
+
+use std::ops::RangeInclusive;
+
+use serde::{Deserialize, Serialize};
+
+use crate::x86_64::{CpuidReg, deserialize_u32_hex, serialize_u32_hex};
+
+/// Parameters for inspecting CPUID definitions.
+#[derive(Debug, Clone, Eq, PartialEq, Serialize, Deserialize)]
+pub struct CpuidParameters {
+    /// The leaf (EAX) parameter used with the CPUID instruction
+    #[serde(
+        serialize_with = "serialize_u32_hex",
+        deserialize_with = "deserialize_u32_hex"
+    )]
+    pub leaf: u32,
+    /// The sub-leaf (ECX) parameter used with the CPUID instruction
+    #[serde(
+        serialize_with = "serialize_range_hex",
+        deserialize_with = "deserialize_range_hex"
+    )]
+    pub sub_leaf: RangeInclusive<u32>,
+    /// The register we are interested in inspecting which gets filled by the CPUID instruction
+    pub register: CpuidReg,
+}
+
+// Only used for (de-)serialization
+#[derive(Debug, Serialize, Deserialize)]
+struct ProvisionalRangeInclusive {
+    #[serde(
+        serialize_with = "serialize_u32_hex",
+        deserialize_with = "deserialize_u32_hex"
+    )]
+    start: u32,
+    #[serde(
+        serialize_with = "serialize_u32_hex",
+        deserialize_with = "deserialize_u32_hex"
+    )]
+    end: u32,
+}
+
+fn serialize_range_hex<S: serde::Serializer>(
+    input: &RangeInclusive<u32>,
+    serializer: S,
+) -> Result<S::Ok, S::Error> {
+    let provisional = ProvisionalRangeInclusive {
+        start: *input.start(),
+        end: *input.end(),
+    };
+    provisional.serialize(serializer)
+}
+
+fn deserialize_range_hex<'de, D: serde::Deserializer<'de>>(
+    deserializer: D,
+) -> Result<RangeInclusive<u32>, D::Error> {
+    let ProvisionalRangeInclusive { start, end } =
+        ProvisionalRangeInclusive::deserialize(deserializer)?;
+    Ok(start..=end)
+}
diff --git a/arch/src/x86_64/cpu_profile/mod.rs b/arch/src/x86_64/cpu_profile/mod.rs
new file mode 100644
index 000000000..a2780443c
--- /dev/null
+++ b/arch/src/x86_64/cpu_profile/mod.rs
@@ -0,0 +1,6 @@
+// Copyright © 2026 Cyberus Technology GmbH
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+pub mod cpuid_adjustments;
diff --git a/arch/src/x86_64/mod.rs b/arch/src/x86_64/mod.rs
index b60b430cf..cb51471c4 100644
--- a/arch/src/x86_64/mod.rs
+++ b/arch/src/x86_64/mod.rs
@@ -7,6 +7,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE-BSD-3-Clause file.
 
+pub mod cpu_profile;
 pub mod interrupts;
 pub mod layout;
 pub mod regs;