Enable MAX_VCPUS and SPLIT_IRQCHIP caps and create VCPU

Signed-off-by: Jake Correnti <[email protected]>

src/launch/mod.rs

@@ -2,6 +2,7 @@
 
 mod linux;
 
+use kvm_bindings::{kvm_enable_cap, KVM_CAP_MAX_VCPUS, KVM_CAP_SPLIT_IRQCHIP};
 use linux::{Capabilities, Cmd, CpuidConfig, InitVm, TdxError};
 
 use bitflags::bitflags;
@@ -18,8 +19,19 @@ pub struct TdxVm {
 
 impl TdxVm {
  /// Create a new TDX VM with KVM
- pub fn new(kvm_fd: &Kvm) -> Result<Self, TdxError> {
+ pub fn new(kvm_fd: &Kvm, max_vcpus: u64) -> Result<Self, TdxError> {
  let vm_fd = kvm_fd.create_vm_with_type(KVM_X86_TDX_VM)?;
+ let mut cap: kvm_enable_cap = Default::default();
+
+ // TDX requires that MAX_VCPUS and SPLIT_IRQCHIP be set
+ cap.cap = KVM_CAP_MAX_VCPUS;
+ cap.args[0] = max_vcpus;
+ vm_fd.enable_cap(&cap).unwrap();
+
+ cap.cap = KVM_CAP_SPLIT_IRQCHIP;
+ cap.args[0] = 24;
+ vm_fd.enable_cap(&cap).unwrap();
+
  Ok(Self { fd: vm_fd })
  }
 

tests/launch.rs

@@ -7,7 +7,8 @@ use tdx::launch::TdxVm;
 #[test]
 fn launch() {
  let kvm_fd = Kvm::new().unwrap();
- let tdx_vm = TdxVm::new(&kvm_fd).unwrap();
+ let tdx_vm = TdxVm::new(&kvm_fd, 100).unwrap();
  let caps = tdx_vm.get_capabilities().unwrap();
  let _ = tdx_vm.init_vm(&kvm_fd, &caps).unwrap();
+ let _vcpufd = tdx_vm.fd.create_vcpu(0).unwrap();
 }