vmm: support injecting NMI

Inject NMI interrupt when needed, by call ioctl KVM_NMI.

Signed-off-by: Yi Wang <foxywang@tencent.com>

hypervisor/src/cpu.rs

@@ -278,6 +278,11 @@ pub enum HypervisorCpuError {
     #[cfg(feature = "sev_snp")]
     #[error("Failed to set sev control register: {0}")]
     SetSevControlRegister(#[source] anyhow::Error),
+
+    /// Error injecting NMI
+    ///
+    #[error("Failed to inject NMI")]
+    Nmi(#[source] anyhow::Error),
 }
 
 #[derive(Debug)]
@@ -505,4 +510,12 @@ pub trait Vcpu: Send + Sync {
     fn set_sev_control_register(&self, _reg: u64) -> Result<()> {
         unimplemented!()
     }
+
+    #[cfg(target_arch = "x86_64")]
+    ///
+    /// Trigger NMI interrupt
+    ///
+    fn nmi(&self) -> Result<()> {
+        unimplemented!()
+    }
 }

hypervisor/src/kvm/mod.rs

@@ -105,6 +105,15 @@ pub use {
 #[cfg(target_arch = "x86_64")]
 const KVM_CAP_SGX_ATTRIBUTE: u32 = 196;
 
+#[cfg(target_arch = "x86_64")]
+use vmm_sys_util::ioctl_io_nr;
+
+#[cfg(all(not(feature = "tdx"), target_arch = "x86_64"))]
+use vmm_sys_util::ioctl_ioc_nr;
+
+#[cfg(target_arch = "x86_64")]
+ioctl_io_nr!(KVM_NMI, kvm_bindings::KVMIO, 0x9a);
+
 #[cfg(feature = "tdx")]
 const KVM_EXIT_TDX: u32 = 50;
 #[cfg(feature = "tdx")]
@@ -2312,6 +2321,23 @@ impl cpu::Vcpu for KvmVcpu {
             Ok(_) => Ok(()),
         }
     }
+
+    #[cfg(target_arch = "x86_64")]
+    ///
+    /// Trigger NMI interrupt
+    ///
+    fn nmi(&self) -> cpu::Result<()> {
+        match self.fd.nmi() {
+            Err(e) => {
+                if e.errno() == libc::EIO {
+                    Ok(())
+                } else {
+                    Err(cpu::HypervisorCpuError::Nmi(e.into()))
+                }
+            }
+            Ok(_) => Ok(()),
+        }
+    }
 }
 
 impl KvmVcpu {