From 2ad615cd320708f3f8ae12765780b83e7652732f Mon Sep 17 00:00:00 2001
From: Rob Bradford <robert.bradford@intel.com>
Date: Tue, 4 May 2021 16:13:10 +0000
Subject: [PATCH] vmm: Validate config upon hotplug

Create a temporary copy of the config, add the new device and validate
that. This needs to be done separately to adding it to the config to
avoid race conditions that might be result in config changes being
overwritten.

Fixes: #2564

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
---
 vmm/src/vm.rs | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/vmm/src/vm.rs b/vmm/src/vm.rs
index 636458473..d3ba84efa 100644
--- a/vmm/src/vm.rs
+++ b/vmm/src/vm.rs
@@ -1253,6 +1253,13 @@ impl Vm {
     }
 
     pub fn add_device(&mut self, mut _device_cfg: DeviceConfig) -> Result<PciDeviceInfo> {
+        {
+            // Validate on a clone of the config
+            let mut config = self.config.lock().unwrap().clone();
+            Self::add_to_config(&mut config.devices, _device_cfg.clone());
+            config.validate().map_err(Error::ConfigValidation)?;
+        }
+
         let pci_device_info = self
             .device_manager
             .lock()
@@ -1323,6 +1330,13 @@ impl Vm {
     }
 
     pub fn add_disk(&mut self, mut _disk_cfg: DiskConfig) -> Result<PciDeviceInfo> {
+        {
+            // Validate on a clone of the config
+            let mut config = self.config.lock().unwrap().clone();
+            Self::add_to_config(&mut config.disks, _disk_cfg.clone());
+            config.validate().map_err(Error::ConfigValidation)?;
+        }
+
         let pci_device_info = self
             .device_manager
             .lock()
@@ -1347,6 +1361,13 @@ impl Vm {
     }
 
     pub fn add_fs(&mut self, mut _fs_cfg: FsConfig) -> Result<PciDeviceInfo> {
+        {
+            // Validate on a clone of the config
+            let mut config = self.config.lock().unwrap().clone();
+            Self::add_to_config(&mut config.fs, _fs_cfg.clone());
+            config.validate().map_err(Error::ConfigValidation)?;
+        }
+
         let pci_device_info = self
             .device_manager
             .lock()
@@ -1371,6 +1392,13 @@ impl Vm {
     }
 
     pub fn add_pmem(&mut self, mut _pmem_cfg: PmemConfig) -> Result<PciDeviceInfo> {
+        {
+            // Validate on a clone of the config
+            let mut config = self.config.lock().unwrap().clone();
+            Self::add_to_config(&mut config.pmem, _pmem_cfg.clone());
+            config.validate().map_err(Error::ConfigValidation)?;
+        }
+
         let pci_device_info = self
             .device_manager
             .lock()
@@ -1395,6 +1423,13 @@ impl Vm {
     }
 
     pub fn add_net(&mut self, mut _net_cfg: NetConfig) -> Result<PciDeviceInfo> {
+        {
+            // Validate on a clone of the config
+            let mut config = self.config.lock().unwrap().clone();
+            Self::add_to_config(&mut config.net, _net_cfg.clone());
+            config.validate().map_err(Error::ConfigValidation)?;
+        }
+
         let pci_device_info = self
             .device_manager
             .lock()
@@ -1423,6 +1458,13 @@ impl Vm {
             return Err(Error::TooManyVsockDevices);
         }
 
+        {
+            // Validate on a clone of the config
+            let mut config = self.config.lock().unwrap().clone();
+            config.vsock = Some(_vsock_cfg.clone());
+            config.validate().map_err(Error::ConfigValidation)?;
+        }
+
         let pci_device_info = self
             .device_manager
             .lock()