vm-virtio: pci: Expect an identifier upon device creation

This identifier is chosen from the DeviceManager so that it will manage
all identifiers across the VM, which will ensure uniqueness.

It is based off the name from the virtio device attached to this
transport layer.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

vm-virtio/src/transport/pci_device.rs

@@ -259,6 +259,8 @@ const VIRTIO_PCI_VENDOR_ID: u16 = 0x1af4;
 const VIRTIO_PCI_DEVICE_ID_BASE: u16 = 0x1040; // Add to device type to get device ID.
 
 pub struct VirtioPciDevice {
+    id: String,
+
     // PCI configuration registers.
     configuration: PciConfiguration,
 
@@ -308,6 +310,7 @@ pub struct VirtioPciDevice {
 impl VirtioPciDevice {
     /// Constructs a new PCI transport for the given virtio device.
     pub fn new(
+        id: String,
         memory: GuestMemoryAtomic<GuestMemoryMmap>,
         device: Arc<Mutex<dyn VirtioDevice>>,
         msix_num: u16,
@@ -384,6 +387,7 @@ impl VirtioPciDevice {
         );
 
         let mut virtio_pci_device = VirtioPciDevice {
+            id,
             configuration,
             common_config: VirtioPciCommonConfig {
                 driver_status: 0,
@@ -962,6 +966,10 @@ impl Pausable for VirtioPciDevice {
     }
 }
 
-impl Snapshottable for VirtioPciDevice {}
+impl Snapshottable for VirtioPciDevice {
+    fn id(&self) -> String {
+        self.id.clone()
+    }
+}
 impl Transportable for VirtioPciDevice {}
 impl Migratable for VirtioPciDevice {}

vmm/src/device_manager.rs

@@ -88,6 +88,8 @@ const IOMMU_DEVICE_NAME: &str = "iommu";
 
 #[cfg(feature = "mmio_support")]
 const VIRTIO_MMIO_DEVICE_NAME_PREFIX: &str = "virtio-mmio";
+#[cfg(feature = "pci_support")]
+const VIRTIO_PCI_DEVICE_NAME_PREFIX: &str = "virtio-pci";
 
 /// Errors associated with device manager
 #[derive(Debug)]
@@ -1933,8 +1935,10 @@ impl DeviceManager {
         pci: &mut PciBus,
         iommu_mapping: &Option<Arc<IommuMapping>>,
         interrupt_manager: &Arc<dyn InterruptManager<GroupConfig = MsiIrqGroupConfig>>,
-        id: String,
+        virtio_device_id: String,
     ) -> DeviceManagerResult<u32> {
+        let id = format!("{}-{}", VIRTIO_PCI_DEVICE_NAME_PREFIX, virtio_device_id);
+
         // Allows support for one MSI-X vector per queue. It also adds 1
         // as we need to take into account the dedicated vector to notify
         // about a virtio config change.
@@ -1972,6 +1976,7 @@ impl DeviceManager {
 
         let memory = self.memory_manager.lock().unwrap().guest_memory();
         let mut virtio_pci_device = VirtioPciDevice::new(
+            id,
             memory,
             virtio_device,
             msix_num,
@@ -1980,7 +1985,8 @@ impl DeviceManager {
         )
         .map_err(DeviceManagerError::VirtioDevice)?;
 
-        let mut allocator = self.address_manager.allocator.lock().unwrap();
+        let allocator = self.address_manager.allocator.clone();
+        let mut allocator = allocator.lock().unwrap();
         let bars = virtio_pci_device
             .allocate_bars(&mut allocator)
             .map_err(DeviceManagerError::AllocateBars)?;
@@ -2005,10 +2011,10 @@ impl DeviceManager {
         self.bus_devices
             .push(Arc::clone(&virtio_pci_device) as Arc<Mutex<dyn BusDevice>>);
 
-        if self.pci_id_list.contains_key(&id) {
+        if self.pci_id_list.contains_key(&virtio_device_id) {
             return Err(DeviceManagerError::DeviceIdAlreadyInUse);
         }
-        self.pci_id_list.insert(id, pci_device_bdf);
+        self.pci_id_list.insert(virtio_device_id, pci_device_bdf);
 
         pci.register_mapping(
             virtio_pci_device.clone(),
@@ -2018,9 +2024,7 @@ impl DeviceManager {
         )
         .map_err(DeviceManagerError::AddPciDevice)?;
 
-        let migratable = Arc::clone(&virtio_pci_device) as Arc<Mutex<dyn Migratable>>;
+        self.add_migratable_device(Arc::clone(&virtio_pci_device) as Arc<Mutex<dyn Migratable>>);
-        let id = migratable.lock().unwrap().id();
-        self.migratable_devices.push((id, migratable));
 
         Ok(pci_device_bdf)
     }