arch: Introduce MSR CPU profile data

We introduce a type describing MSR adjustments associated with a
CPU profile.

The upcoming CPU profile generation tool will serialize instances of
this struct when generating a CPU profile.

A follow up PR will take care of filling out the currently stubbed
`msr_data` method.

Signed-off-by: Oliver Anderson <oliver.anderson@cyberus-technology.de>
On-behalf-of: SAP oliver.anderson@sap.com

arch/src/x86_64/cpu_profile/mod.rs

@@ -9,6 +9,7 @@ use hypervisor::arch::x86::CpuIdEntry;
 use crate::x86_64::cpu_profile::cpuid_adjustments::{
     CpuidOutputRegisterAdjustments, CpuidProfileData, MissingCpuidEntriesError,
 };
+use crate::x86_64::cpu_profile::msr_adjustments::MsrProfileData;
 use crate::x86_64::{AMX_TILECFG_BIT, AMX_TILEDATA_BIT, CpuidReg};
 
 /// Mask indicating availability of the AMX TILECFG state component
@@ -64,6 +65,13 @@ impl CpuProfile {
             CpuProfile::Host => None,
         }
     }
+
+    /// Obtain MSR adjustment data related to the given CPU profile.
+    fn msr_data(&self) -> Option<MsrProfileData> {
+        match self {
+            CpuProfile::Host => None,
+        }
+    }
 }
 
 /// See [`CpuProfile::adjust_cpuid`](CpuProfile::adjust_cpuid)

arch/src/x86_64/cpu_profile/msr_adjustments.rs

@@ -89,3 +89,19 @@ impl FeatureMsrAdjustment {
         }
     }
 }
+
+/// Data describing MSR adjustments related to a CPU profile.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
+pub struct MsrProfileData {
+    /// Describes feature MSR adjustments necessary to become compatible with
+    /// the desired target.
+    pub adjustments: Vec<(RegisterAddress, FeatureMsrAdjustment)>,
+    /// List of the MSRs that the CPU profile requires.
+    ///
+    /// When applying a CPU profile then the union of the sets of MSRs obtained
+    /// from `Hypervisor::get_feature_msrs` and `Hypervisor::get_msr_index_list`
+    /// must necessarily contain all MSRs listed here. Otherwise the host is
+    /// considered incompatible with the CPU profile. Exceptions are made for
+    /// missing Hyper-V MSRs when `kvm_hyperv=off`.
+    pub required_msrs: Vec<RegisterAddress>,
+}