Add support for KVM_CAP_X86_SMM / KVM_SMI

Allow VMMs to inject System Management Interrupts (SMIs) into the
guest via the KVM_SMI vcpu ioctl, which is available if the
KVM_CAP_X86_SMM capability is present.

Signed-off-by: Carlos López <carlos.lopez@suse.com>

Author: 00xc

CHANGELOG.md

@@ -5,8 +5,10 @@
 ## Changed
 - [[#234](https://github.com/rust-vmm/kvm-ioctls/issues/234)] vcpu: export
 reg_size as a public method.
--[[#243](https://github.com/rust-vmm/kvm-ioctls/pull/243)] derived the `Copy`
- trait for `IoEventAddress` and `NoDatamatch`.
+- [[#243](https://github.com/rust-vmm/kvm-ioctls/pull/243)] derived the `Copy`
+  trait for `IoEventAddress` and `NoDatamatch`.
+- [[#242](https://github.com/rust-vmm/kvm-ioctls/pull/242)] x86: add support
+  for SMI injection via `Vcpu::smi()` (`KVM_SMI` ioctl).
 
 # v0.15.0
 

src/cap.rs

@@ -146,6 +146,8 @@ pub enum Cap {
     CheckExtensionVm = KVM_CAP_CHECK_EXTENSION_VM,
     S390UserSigp = KVM_CAP_S390_USER_SIGP,
     #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+    X86Smm = KVM_CAP_X86_SMM,
+    #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
     SplitIrqchip = KVM_CAP_SPLIT_IRQCHIP,
     ArmPmuV3 = KVM_CAP_ARM_PMU_V3,
     ImmediateExit = KVM_CAP_IMMEDIATE_EXIT,

src/ioctls/vcpu.rs

@@ -1720,6 +1720,29 @@ impl VcpuFd {
         // `get_vcpu_map_size`, so this region is in bounds
         unsafe { &mut kvm_run.s.regs }
     }
+
+    /// Triggers an SMI on the virtual CPU.
+    ///
+    /// See documentation for `KVM_SMI`.
+    ///
+    /// ```rust
+    /// # use kvm_ioctls::{Kvm, Cap};
+    /// let kvm = Kvm::new().unwrap();
+    /// let vm = kvm.create_vm().unwrap();
+    /// let vcpu = vm.create_vcpu(0).unwrap();
+    /// if kvm.check_extension(Cap::X86Smm) {
+    ///     vcpu.smi().unwrap();
+    /// }
+    /// ```
+    #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+    pub fn smi(&self) -> Result<()> {
+        // SAFETY: Safe because we call this with a Vcpu fd and we trust the kernel.
+        let ret = unsafe { ioctl(self, KVM_SMI()) };
+        match ret {
+            0 => Ok(()),
+            _ => Err(errno::Error::last()),
+        }
+    }
 }
 
 /// Helper function to create a new `VcpuFd`.

src/kvm_ioctls.rs

@@ -240,6 +240,10 @@ ioctl_ior_nr!(KVM_ARM_PREFERRED_TARGET, KVMIO, 0xaf, kvm_vcpu_init);
 #[cfg(any(target_arch = "arm", target_arch = "aarch64"))]
 ioctl_iowr_nr!(KVM_GET_REG_LIST, KVMIO, 0xb0, kvm_reg_list);
 
+/* Available with KVM_CAP_X86_SMM */
+#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+ioctl_io_nr!(KVM_SMI, KVMIO, 0xb7);
+
 /* Available with KVM_CAP_ARM_SVE */
 #[cfg(target_arch = "aarch64")]
 ioctl_iow_nr!(KVM_ARM_VCPU_FINALIZE, KVMIO, 0xc2, std::os::raw::c_int);