From 6d2224f1ba0ac56d96d83fabb426f63869770cfd Mon Sep 17 00:00:00 2001
From: Rob Bradford <robert.bradford@intel.com>
Date: Fri, 18 Mar 2022 16:57:12 +0000
Subject: [PATCH] vmm: device_manager: Create IOMMU mapping for hotplugged
 virtio devices

Previously it was not possible to enable vIOMMU for a virtio device.
However with the ability to place an entire PCI segment behind the
IOMMU the IOMMU mapping needs to be setup for the virtio device if it is
behind the IOMMU.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
---
 vmm/src/device_manager.rs | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/vmm/src/device_manager.rs b/vmm/src/device_manager.rs
index 41fb1b5b9..c685759a0 100644
--- a/vmm/src/device_manager.rs
+++ b/vmm/src/device_manager.rs
@@ -884,6 +884,7 @@ pub struct DeviceManager {
 
     // Paravirtualized IOMMU
     iommu_device: Option<Arc<Mutex<virtio_devices::Iommu>>>,
+    iommu_mapping: Option<Arc<IommuMapping>>,
 
     // PCI information about devices attached to the paravirtualized IOMMU
     // It contains the virtual IOMMU PCI BDF along with the list of PCI BDF
@@ -1046,6 +1047,7 @@ impl DeviceManager {
             passthrough_device: None,
             vfio_container: None,
             iommu_device: None,
+            iommu_mapping: None,
             iommu_attached_devices: None,
             pci_segments,
             device_tree,
@@ -1219,7 +1221,7 @@ impl DeviceManager {
     ) -> DeviceManagerResult<()> {
         let iommu_id = String::from(IOMMU_DEVICE_NAME);
 
-        let (iommu_device, iommu_mapping) = if self.config.lock().unwrap().iommu {
+        let iommu_device = if self.config.lock().unwrap().iommu {
             let (device, mapping) = virtio_devices::Iommu::new(
                 iommu_id.clone(),
                 self.seccomp_action.clone(),
@@ -1231,6 +1233,7 @@ impl DeviceManager {
             .map_err(DeviceManagerError::CreateVirtioIommu)?;
             let device = Arc::new(Mutex::new(device));
             self.iommu_device = Some(Arc::clone(&device));
+            self.iommu_mapping = Some(mapping);
 
             // Fill the device tree with a new node. In case of restore, we
             // know there is nothing to do, so we can simply override the
@@ -1240,20 +1243,23 @@ impl DeviceManager {
                 .unwrap()
                 .insert(iommu_id.clone(), device_node!(iommu_id, device));
 
-            (Some(device), Some(mapping))
+            Some(device)
         } else {
-            (None, None)
+            None
         };
 
         let mut iommu_attached_devices = Vec::new();
         {
             for handle in virtio_devices {
-                let mapping: &Option<Arc<IommuMapping>> =
-                    if handle.iommu { &iommu_mapping } else { &None };
+                let mapping: Option<Arc<IommuMapping>> = if handle.iommu {
+                    self.iommu_mapping.clone()
+                } else {
+                    None
+                };
 
                 let dev_id = self.add_virtio_pci_device(
                     handle.virtio_device,
-                    mapping,
+                    &mapping,
                     handle.id,
                     handle.pci_segment,
                     handle.dma_handler,
@@ -3943,9 +3949,15 @@ impl DeviceManager {
         // for instance.
         self.virtio_devices.push(handle.clone());
 
+        let mapping: Option<Arc<IommuMapping>> = if handle.iommu {
+            self.iommu_mapping.clone()
+        } else {
+            None
+        };
+
         let bdf = self.add_virtio_pci_device(
             handle.virtio_device,
-            &None,
+            &mapping,
             handle.id.clone(),
             handle.pci_segment,
             handle.dma_handler,