vmm: pci: Move creation of vfio_user::Client to DeviceManager

By moving this from the VfioUserPciDevice to DeviceManager the client
can be reused for handling DMA mapping behind an IOMMU.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>

Cargo.lock

@@ -1398,6 +1398,7 @@ dependencies = [
  "versionize",
  "versionize_derive",
  "vfio-ioctls",
+ "vfio_user",
  "vhdx",
  "virtio-devices",
  "vm-allocator",

pci/src/vfio_user.rs

@@ -11,7 +11,6 @@ use crate::{
 use hypervisor::HypervisorVmError;
 use std::any::Any;
 use std::os::unix::prelude::AsRawFd;
-use std::path::Path;
 use std::ptr::null_mut;
 use std::sync::{Arc, Barrier, Mutex};
 use std::u32;
@@ -61,12 +60,10 @@ impl PciSubclass for PciVfioUserSubclass {
 impl VfioUserPciDevice {
     pub fn new(
         vm: &Arc<dyn hypervisor::Vm>,
-        path: &Path,
+        client: Arc<Mutex<Client>>,
         msi_interrupt_manager: &Arc<dyn InterruptManager<GroupConfig = MsiIrqGroupConfig>>,
         legacy_interrupt_group: Option<Arc<dyn InterruptSourceGroup>>,
     ) -> Result<Self, VfioUserPciDeviceError> {
-        let mut client = Client::new(path).map_err(VfioUserPciDeviceError::Client)?;
-
         // This is used for the BAR and capabilities only
         let configuration = PciConfiguration::new(
             0,
@@ -80,12 +77,15 @@ impl VfioUserPciDevice {
             0,
             None,
         );
-        if client.resettable() {
-            client.reset().map_err(VfioUserPciDeviceError::Client)?;
+        let resettable = client.lock().unwrap().resettable();
+        if resettable {
+            client
+                .lock()
+                .unwrap()
+                .reset()
+                .map_err(VfioUserPciDeviceError::Client)?;
         }
 
-        let client = Arc::new(Mutex::new(client));
-
         let vfio_wrapper = VfioUserClientWrapper {
             client: client.clone(),
         };

vmm/Cargo.toml

@@ -45,6 +45,7 @@ uuid = "0.8.2"
 versionize = "0.1.6"
 versionize_derive = "0.1.4"
 vfio-ioctls = { git = "https://github.com/rust-vmm/vfio-ioctls", branch = "main", default-features = false }
+vfio_user = { path = "../vfio_user" }
 vhdx = { path = "../vhdx" }
 virtio-devices = { path = "../virtio-devices" }
 vm-allocator = { path = "../vm-allocator" }

vmm/src/device_manager.rs

@@ -442,6 +442,9 @@ pub enum DeviceManagerError {
     /// Failed removing DMA mapping handler from virtio-mem device.
     RemoveDmaMappingHandlerVirtioMem(virtio_devices::mem::Error),
 
+    /// Failed to create vfio-user client
+    VfioUserCreateClient(vfio_user::Error),
+
     /// Failed to create VFIO user device
     VfioUserCreate(VfioUserPciDeviceError),
 
@@ -3105,9 +3108,14 @@ impl DeviceManager {
             None
         };
 
+        let client = Arc::new(Mutex::new(
+            vfio_user::Client::new(&device_cfg.socket)
+                .map_err(DeviceManagerError::VfioUserCreateClient)?,
+        ));
+
         let mut vfio_user_pci_device = VfioUserPciDevice::new(
             &self.address_manager.vm,
-            &device_cfg.socket,
+            client,
             &self.msi_interrupt_manager,
             legacy_interrupt_group,
         )