kvm: Added KVM MSR Store access

ScaleComputing · May 3, 2024 · 7dc2235 · 7dc2235
1 parent 1b7d256
commit 7dc2235
Show file tree

Hide file tree

Showing 5 changed files with 120 additions and 39 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -13,8 +13,8 @@ serde_yaml = "0.8"
 enum_dispatch = "0.3.8"
 
 [target.'cfg(target_os = "linux")'.dependencies]
-kvm-ioctls = { version = "0.12.0", optional = true }
-kvm-bindings = { version = "0.6.0", features = ["fam-wrappers"], optional = true }
+kvm-ioctls = { version = "0.17", optional = true }
+kvm-bindings = { version = "0.8", features = ["fam-wrappers"], optional = true }
 
 [features]
 default = ["use_msr", "kvm"]

diff --git a/src/kvm.rs b/src/kvm.rs
@@ -1,6 +1,9 @@
+use crate::msr::{self, MSRValue, MsrStore};
+
 use super::CpuidDB;
 use core::arch::x86_64::CpuidResult;
-use kvm_bindings::{KVM_CPUID_FLAG_SIGNIFCANT_INDEX, KVM_MAX_CPUID_ENTRIES};
+use kvm_bindings::{kvm_msr_entry, Msrs, KVM_CPUID_FLAG_SIGNIFCANT_INDEX, KVM_MAX_CPUID_ENTRIES};
+use std::error::Error;
 
 /** Wrap information from kvm
  *
@@ -39,3 +42,50 @@ impl CpuidDB for KvmInfo {
         })
     }
 }
+
+pub struct KvmMsrInfo {
+    msr_info: kvm_bindings::Msrs,
+}
+
+impl KvmMsrInfo {
+    pub fn new(kvm: &kvm_ioctls::Kvm) -> Result<Self, Box<dyn Error>> {
+        let msr_features = kvm.get_msr_feature_index_list()?;
+        let mut msrs = Msrs::from_entries(
+            &msr_features
+                .as_slice()
+                .iter()
+                .map(|&index| kvm_msr_entry {
+                    index,
+                    ..Default::default()
+                })
+                .collect::<Vec<_>>(),
+        )?;
+        kvm.get_msrs(&mut msrs)?;
+        Ok(KvmMsrInfo { msr_info: msrs })
+    }
+}
+
+impl MsrStore for KvmMsrInfo {
+    fn is_empty(&self) -> bool {
+        false
+    }
+    fn get_value<'a>(
+        &self,
+        desc: &'a crate::msr::MSRDesc,
+    ) -> std::result::Result<crate::msr::MSRValue<'a>, crate::msr::Error> {
+        self.msr_info
+            .as_slice()
+            .iter()
+            .find_map(|entry| {
+                if entry.index == desc.address {
+                    Some(MSRValue {
+                        desc,
+                        value: entry.data,
+                    })
+                } else {
+                    None
+                }
+            })
+            .ok_or_else(|| msr::Error::NotAvailible {})
+    }
+}
diff --git a/src/main.rs b/src/main.rs
@@ -76,8 +76,10 @@ impl Command for Disp {
                 }
             }
 
+            #[cfg(feature = "use_msr")]
             if !self.skip_msr {
-                if msr::LINUX_MSR_AVAILIBLE {
+                #[cfg(all(target_os = "linux"))]
+                {
                     match msr::LinuxMsrStore::new() {
                         Ok(linux_store) => {
                             println!("MSRS:");
@@ -91,6 +93,25 @@ impl Command for Disp {
                         Err(e) => println!("Error checking all msrs: {}", e),
                     }
                 }
+                #[cfg(all(target_os = "linux", feature = "kvm"))]
+                if !self.skip_kvm {
+                    use cpuinfo::kvm::KvmMsrInfo;
+                    use kvm_ioctls::Kvm;
+                    println!("KVM-MSR:");
+                    if let Err(e) = {
+                        let kvm = Kvm::new()?;
+                        let kvm_msr = KvmMsrInfo::new(&kvm)?;
+                        for msr in &config.msrs {
+                            match kvm_msr.get_value(msr) {
+                                Ok(value) => println!("{}", value),
+                                Err(err) => println!("{} Error : {}", msr, err),
+                            }
+                        }
+                        Ok::<_, Box<dyn Error>>(())
+                    } {
+                        println!("Error Processing KVM-MSR: {}", e);
+                    }
+                }
             }
             Ok(())
         }
@@ -120,7 +141,7 @@ fn collect_facts(
         })
         .collect();
 
-    if msr_store.is_empty() {
+    if !msr_store.is_empty() {
         for msr in &config.msrs {
             if let Ok(value) = msr_store.get_value(msr) {
                 let mut facts = value.collect_facts();
@@ -137,41 +158,49 @@ fn collect_facts(
 
 impl Command for Facts {
     fn run(&self, config: &Definition) -> Result<(), Box<dyn std::error::Error>> {
-        #[cfg(all(target_os = "linux", feature = "kvm"))]
-        let kvm_option = {
-            use cpuinfo::kvm::KvmInfo;
-            use kvm_ioctls::Kvm;
-            if self.use_kvm {
-                println!("using kvm");
-                let kvm = Kvm::new()?;
-                Some(KvmInfo::new(&kvm)?)
-            } else {
-                None
-            }
-        };
-
         let (cpuid_source, msr_source): (_, Box<dyn MsrStore>) = {
             #[cfg(all(target_os = "linux", feature = "kvm"))]
             {
-                if let Some(kvm_info) = kvm_option {
+                if self.use_kvm {
+                    use cpuinfo::kvm::KvmInfo;
+                    use kvm::KvmMsrInfo;
+                    use kvm_ioctls::Kvm;
+                    let kvm = Kvm::new()?;
                     (
-                        kvm_info.into(),
-                        Box::new(msr::EmptyMSR {}) as Box<dyn MsrStore>,
+                        KvmInfo::new(&kvm)?.into(),
+                        Box::new(KvmMsrInfo::new(&kvm)?) as Box<dyn MsrStore>,
                     )
                 } else {
-                    (
-                        CpuidType::func(),
-                        Box::new(msr::LinuxMsrStore::new()?) as Box<dyn MsrStore>,
-                    )
+                    let msr = {
+                        #[cfg(feature = "use_msr")]
+                        {
+                            Box::new(msr::LinuxMsrStore::new()?) as Box<dyn MsrStore>
+                        }
+                        #[cfg(not(feature = "use_msr"))]
+                        {
+                            Box::new(msr::EmptyMSR {})
+                        }
+                    };
+                    (CpuidType::func(), msr)
                 }
             }
-            #[cfg(any(not(target_os = "linux"), not(feature = "kvm")))]
+            #[cfg(all(target_os = "linux", not(feature = "kvm"), feature = "use_msr"))]
             {
                 (
                     CpuidType::func(),
                     Box::new(msr::LinuxMsrStore::new()?) as Box<dyn MsrStore>,
                 )
             }
+            #[cfg(all(
+                not(feature = "kvm"),
+                any(not(target_os = "linux"), not(feature = "use_msr"))
+            ))]
+            {
+                (
+                    CpuidType::func(),
+                    Box::new(msr::EmptyMSR {}) as Box<dyn MsrStore>,
+                )
+            }
         };
         println!(
             "{}",

diff --git a/src/msr.rs b/src/msr.rs
@@ -53,11 +53,6 @@ impl MsrStore for EmptyMSR {
     }
 }
 
-#[cfg(all(target_os = "linux", feature = "use_msr"))]
-pub const LINUX_MSR_AVAILIBLE: bool = true;
-#[cfg(any(not(target_os = "linux"), not(feature = "use_msr")))]
-pub const LINUX_MSR_AVAILIBLE: bool = false;
-
 #[cfg(all(target_os = "linux", feature = "use_msr"))]
 pub struct LinuxMsrStore {
     msr_device: fs::File,