From c021dda2677a36e679d5e5033ac22389e485976f Mon Sep 17 00:00:00 2001
From: Sebastien Boeuf <sebastien.boeuf@intel.com>
Date: Tue, 7 Jun 2022 16:35:53 +0200
Subject: [PATCH] pci, vmm: Add migratable support to VFIO devices

Based on recent changes to VfioPciDevice, the VFIO devices can now be
migrated.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
---
 pci/src/vfio.rs           | 10 ++++++++--
 vmm/src/device_manager.rs |  7 ++-----
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/pci/src/vfio.rs b/pci/src/vfio.rs
index 88ad93b30..91ca831f0 100644
--- a/pci/src/vfio.rs
+++ b/pci/src/vfio.rs
@@ -1153,6 +1153,7 @@ impl VfioPciDevice {
         legacy_interrupt_group: Option<Arc<dyn InterruptSourceGroup>>,
         iommu_attached: bool,
         bdf: PciBdf,
+        restoring: bool,
     ) -> Result<Self, VfioPciError> {
         let device = Arc::new(device);
         device.reset();
@@ -1185,8 +1186,13 @@ impl VfioPciDevice {
             vfio_wrapper: Arc::new(vfio_wrapper) as Arc<dyn Vfio>,
         };
 
-        common.parse_capabilities(bdf);
-        common.initialize_legacy_interrupt()?;
+        // No need to parse capabilities from the device if on the restore path.
+        // The initialization will be performed later when restore() will be
+        // called.
+        if !restoring {
+            common.parse_capabilities(bdf);
+            common.initialize_legacy_interrupt()?;
+        }
 
         let vfio_pci_device = VfioPciDevice {
             id,
diff --git a/vmm/src/device_manager.rs b/vmm/src/device_manager.rs
index 0d811f456..928a20edd 100644
--- a/vmm/src/device_manager.rs
+++ b/vmm/src/device_manager.rs
@@ -2978,10 +2978,6 @@ impl DeviceManager {
         device_cfg: &mut DeviceConfig,
     ) -> DeviceManagerResult<(PciBdf, String)> {
         let vfio_name = if let Some(id) = &device_cfg.id {
-            if self.device_tree.lock().unwrap().contains_key(id) {
-                return Err(DeviceManagerError::DeviceIdAlreadyInUse);
-            }
-
             id.clone()
         } else {
             let id = self.next_device_name(VFIO_DEVICE_NAME_PREFIX)?;
@@ -3090,6 +3086,7 @@ impl DeviceManager {
             legacy_interrupt_group,
             device_cfg.iommu,
             pci_device_bdf,
+            self.restoring,
         )
         .map_err(DeviceManagerError::VfioPciCreate)?;
 
@@ -3111,7 +3108,7 @@ impl DeviceManager {
             })
             .map_err(DeviceManagerError::VfioMapRegion)?;
 
-        let mut node = device_node!(vfio_name);
+        let mut node = device_node!(vfio_name, vfio_pci_device);
 
         // Update the device tree with correct resource information.
         node.resources = new_resources;