hypervisor, vmm: move away from CpuId type

CpuId is an alias type for the flexible array structure type over
CpuIdEntry. The type itself and the type of the element in the array
portion are tied to the underlying hypervisor.

Switch to using CpuIdEntry slice or vector directly. The construction of
CpuId type is left to hypervisors.

This allows us to decouple CpuIdEntry from hypervisors more easily.

No functional change intended.

Signed-off-by: Wei Liu <liuwe@microsoft.com>

hypervisor/src/cpu.rs

@@ -19,7 +19,7 @@ use crate::kvm::{TdxExitDetails, TdxExitStatus};
 #[cfg(target_arch = "x86_64")]
 use crate::x86_64::Xsave;
 #[cfg(target_arch = "x86_64")]
-use crate::x86_64::{CpuId, LapicState};
+use crate::x86_64::{CpuIdEntry, LapicState};
 #[cfg(target_arch = "x86_64")]
 use crate::x86_64::{ExtendedControlRegisters, FpuState, MsrEntries, VcpuEvents};
 use crate::CpuState;
@@ -312,7 +312,7 @@ pub trait Vcpu: Send + Sync {
     ///
     /// X86 specific call to setup the CPUID registers.
     ///
-    fn set_cpuid2(&self, cpuid: &CpuId) -> Result<()>;
+    fn set_cpuid2(&self, cpuid: &[CpuIdEntry]) -> Result<()>;
     #[cfg(target_arch = "x86_64")]
     ///
     /// X86 specific call to enable HyperV SynIC
@@ -322,7 +322,7 @@ pub trait Vcpu: Send + Sync {
     ///
     /// X86 specific call to retrieve the CPUID registers.
     ///
-    fn get_cpuid2(&self, num_entries: usize) -> Result<CpuId>;
+    fn get_cpuid2(&self, num_entries: usize) -> Result<Vec<CpuIdEntry>>;
     #[cfg(target_arch = "x86_64")]
     ///
     /// Returns the state of the LAPIC (Local Advanced Programmable Interrupt Controller).

hypervisor/src/hypervisor.rs

@@ -11,7 +11,7 @@
 use crate::kvm::TdxCapabilities;
 use crate::vm::Vm;
 #[cfg(target_arch = "x86_64")]
-use crate::x86_64::CpuId;
+use crate::x86_64::CpuIdEntry;
 #[cfg(target_arch = "x86_64")]
 use crate::x86_64::MsrList;
 use std::sync::Arc;
@@ -100,7 +100,7 @@ pub trait Hypervisor: Send + Sync {
     ///
     /// Get the supported CpuID
     ///
-    fn get_cpuid(&self) -> Result<CpuId>;
+    fn get_cpuid(&self) -> Result<Vec<CpuIdEntry>>;
     ///
     /// Check particular extensions if any
     ///

hypervisor/src/kvm/mod.rs

@@ -755,7 +755,15 @@ impl vm::Vm for KvmVm {
     /// Initialize TDX for this VM
     ///
     #[cfg(feature = "tdx")]
-    fn tdx_init(&self, cpuid: &CpuId, max_vcpus: u32) -> vm::Result<()> {
+    fn tdx_init(&self, cpuid: &[CpuIdEntry], max_vcpus: u32) -> vm::Result<()> {
+        use std::io::{Error, ErrorKind};
+        let kvm_cpuid = kvm_bindings::CpuId::from_entries(cpuid).map_err(|_| {
+            vm::HypervisorVmError::InitializeTdx(Error::new(
+                ErrorKind::Other,
+                "failed to allocate CpuId",
+            ))
+        })?;
+
         #[repr(C)]
         struct TdxInitVm {
             max_vcpus: u32,
@@ -771,7 +779,7 @@ impl vm::Vm for KvmVm {
             max_vcpus,
             tsc_khz: 0,
             attributes: 0,
-            cpuid: cpuid.as_fam_struct_ptr() as u64,
+            cpuid: kvm_cpuid.as_fam_struct_ptr() as u64,
             mrconfigid: [0; 6],
             mrowner: [0; 6],
             mrownerconfig: [0; 6],
@@ -983,10 +991,15 @@ impl hypervisor::Hypervisor for KvmHypervisor {
     ///
     /// X86 specific call to get the system supported CPUID values.
     ///
-    fn get_cpuid(&self) -> hypervisor::Result<CpuId> {
-        self.kvm
+    fn get_cpuid(&self) -> hypervisor::Result<Vec<CpuIdEntry>> {
+        let kvm_cpuid = self
+            .kvm
             .get_supported_cpuid(kvm_bindings::KVM_MAX_CPUID_ENTRIES)
-            .map_err(|e| hypervisor::HypervisorError::GetCpuId(e.into()))
+            .map_err(|e| hypervisor::HypervisorError::GetCpuId(e.into()))?;
+
+        let v = kvm_cpuid.as_slice().to_vec();
+
+        Ok(v)
     }
 
     #[cfg(target_arch = "x86_64")]
@@ -1311,9 +1324,12 @@ impl cpu::Vcpu for KvmVcpu {
     ///
     /// X86 specific call to setup the CPUID registers.
     ///
-    fn set_cpuid2(&self, cpuid: &CpuId) -> cpu::Result<()> {
+    fn set_cpuid2(&self, cpuid: &[CpuIdEntry]) -> cpu::Result<()> {
+        let kvm_cpuid = CpuId::from_entries(cpuid)
+            .map_err(|_| cpu::HypervisorCpuError::SetCpuid(anyhow!("failed to create CpuId")))?;
+
         self.fd
-            .set_cpuid2(cpuid)
+            .set_cpuid2(&kvm_cpuid)
             .map_err(|e| cpu::HypervisorCpuError::SetCpuid(e.into()))
     }
     #[cfg(target_arch = "x86_64")]
@@ -1337,10 +1353,15 @@ impl cpu::Vcpu for KvmVcpu {
     /// X86 specific call to retrieve the CPUID registers.
     ///
     #[cfg(target_arch = "x86_64")]
-    fn get_cpuid2(&self, num_entries: usize) -> cpu::Result<CpuId> {
-        self.fd
+    fn get_cpuid2(&self, num_entries: usize) -> cpu::Result<Vec<CpuIdEntry>> {
+        let kvm_cpuid = self
+            .fd
             .get_cpuid2(num_entries)
-            .map_err(|e| cpu::HypervisorCpuError::GetCpuid(e.into()))
+            .map_err(|e| cpu::HypervisorCpuError::GetCpuid(e.into()))?;
+
+        let v = kvm_cpuid.as_slice().to_vec();
+
+        Ok(v)
     }
     #[cfg(target_arch = "x86_64")]
     ///

hypervisor/src/kvm/x86_64/mod.rs

@@ -52,7 +52,7 @@ pub fn check_required_kvm_extensions(kvm: &Kvm) -> KvmResult<()> {
 }
 #[derive(Clone, Serialize, Deserialize)]
 pub struct VcpuKvmState {
-    pub cpuid: CpuId,
+    pub cpuid: Vec<CpuIdEntry>,
     pub msrs: MsrEntries,
     pub vcpu_events: VcpuEvents,
     pub regs: kvm_regs,

hypervisor/src/mshv/mod.rs

@@ -235,8 +235,8 @@ impl hypervisor::Hypervisor for MshvHypervisor {
     ///
     /// Get the supported CpuID
     ///
-    fn get_cpuid(&self) -> hypervisor::Result<CpuId> {
-        Ok(CpuId::new(1).unwrap())
+    fn get_cpuid(&self) -> hypervisor::Result<Vec<CpuIdEntry>> {
+        Ok(Vec::new())
     }
     #[cfg(target_arch = "x86_64")]
     ///
@@ -254,7 +254,7 @@ impl hypervisor::Hypervisor for MshvHypervisor {
 pub struct MshvVcpu {
     fd: VcpuFd,
     vp_index: u8,
-    cpuid: CpuId,
+    cpuid: Vec<CpuIdEntry>,
     msrs: MsrEntries,
     vm_ops: Option<Arc<dyn vm::VmOps>>,
 }
@@ -563,14 +563,14 @@ impl cpu::Vcpu for MshvVcpu {
     ///
     /// X86 specific call to setup the CPUID registers.
     ///
-    fn set_cpuid2(&self, _cpuid: &CpuId) -> cpu::Result<()> {
+    fn set_cpuid2(&self, _cpuid: &[CpuIdEntry]) -> cpu::Result<()> {
         Ok(())
     }
     #[cfg(target_arch = "x86_64")]
     ///
     /// X86 specific call to retrieve the CPUID registers.
     ///
-    fn get_cpuid2(&self, _num_entries: usize) -> cpu::Result<CpuId> {
+    fn get_cpuid2(&self, _num_entries: usize) -> cpu::Result<Vec<CpuIdEntry>> {
         Ok(self.cpuid.clone())
     }
     #[cfg(target_arch = "x86_64")]
@@ -952,7 +952,7 @@ impl vm::Vm for MshvVm {
         let vcpu = MshvVcpu {
             fd: vcpu_fd,
             vp_index: id,
-            cpuid: CpuId::new(1).unwrap(),
+            cpuid: Vec::new(),
             msrs: self.msrs.clone(),
             vm_ops,
         };

hypervisor/src/vm.rs

@@ -15,7 +15,7 @@ use crate::arch::aarch64::gic::Vgic;
 use crate::cpu::Vcpu;
 use crate::device::Device;
 #[cfg(feature = "tdx")]
-use crate::x86_64::CpuId;
+use crate::x86_64::CpuIdEntry;
 #[cfg(target_arch = "x86_64")]
 use crate::ClockData;
 use crate::CreateDevice;
@@ -342,7 +342,7 @@ pub trait Vm: Send + Sync {
     fn get_dirty_log(&self, slot: u32, base_gpa: u64, memory_size: u64) -> Result<Vec<u64>>;
     #[cfg(feature = "tdx")]
     /// Initalize TDX on this VM
-    fn tdx_init(&self, cpuid: &CpuId, max_vcpus: u32) -> Result<()>;
+    fn tdx_init(&self, cpuid: &[CpuIdEntry], max_vcpus: u32) -> Result<()>;
     #[cfg(feature = "tdx")]
     /// Finalize the configuration of TDX on this VM
     fn tdx_finalize(&self) -> Result<()>;