vmm: Remove the Vmm structure

The Vmm structure is just a placeholder for the KVM instance. We can
create it directly from the VM creation routine instead.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

src/main.rs

@@ -285,7 +285,7 @@ fn main() {
         vm_config.disks,
     );
 
-    if let Err(e) = vmm::boot_kernel(vm_config) {
+    if let Err(e) = vmm::start_vm_loop(vm_config) {
         println!("Guest boot failed: {}", e);
         process::exit(1);
     }

vmm/src/lib.rs

@@ -3,11 +3,9 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
-extern crate kvm_ioctls;
 #[macro_use]
 extern crate log;
 
-use kvm_ioctls::*;
 use std::fmt::{self, Display};
 use std::result;
 
@@ -40,21 +38,9 @@ impl Display for Error {
     }
 }
 
-struct Vmm {
-    kvm: Kvm,
-}
-
-impl Vmm {
-    fn new() -> Result<Self> {
-        let kvm = Kvm::new().expect("new KVM instance creation failed");
-        Ok(Vmm { kvm })
-    }
-}
-
-pub fn boot_kernel(config: VmConfig) -> Result<()> {
+pub fn start_vm_loop(config: VmConfig) -> Result<()> {
     loop {
-        let vmm = Vmm::new()?;
-        let mut vm = Vm::new(&vmm.kvm, &config).map_err(Error::VmNew)?;
+        let mut vm = Vm::new(&config).map_err(Error::VmNew)?;
 
         if vm.start().map_err(Error::VmStart)? == ExitBehaviour::Shutdown {
             break;

vmm/src/vm.rs

@@ -211,6 +211,9 @@ pub enum Error {
 
     /// Failed to join on vCPU threads
     ThreadCleanup,
+
+    /// Failed to create a new KVM instance
+    KvmNew(io::Error),
 }
 pub type Result<T> = result::Result<T, Error>;
 
@@ -533,7 +536,8 @@ fn get_host_cpu_phys_bits() -> u8 {
 }
 
 impl<'a> Vm<'a> {
-    pub fn new(kvm: &Kvm, config: &'a VmConfig) -> Result<Self> {
+    pub fn new(config: &'a VmConfig) -> Result<Self> {
+        let kvm = Kvm::new().map_err(Error::KvmNew)?;
         let kernel = File::open(&config.kernel.path).map_err(Error::KernelFile)?;
         let fd = kvm.create_vm().map_err(Error::VmCreate)?;
         let fd = Arc::new(fd);