vmm: Add iommu=on|off option for --device

Having the virtual IOMMU created with --iommu is one thing, but we also
need a way to decide if a VFIO device should be attached to the virtual
IOMMU or not. That's why we introduce an extra option "iommu" with the
value "on" or "off". By default, the device is not attached, which means
"iommu=off".

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

vmm/src/api/openapi/cloud-hypervisor.yaml

@@ -353,6 +353,9 @@ components:
       properties:
         path:
           type: string
+        iommu:
+          type: boolean
+          default: false
 
     VhostUserConfig:
       required:

vmm/src/config.rs

@@ -572,12 +572,29 @@ impl ConsoleConfig {
 #[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct DeviceConfig {
     pub path: PathBuf,
+    #[serde(default)]
+    pub iommu: bool,
 }
 
 impl DeviceConfig {
     pub fn parse(device: &str) -> Result<Self> {
+        // Split the parameters based on the comma delimiter
+        let params_list: Vec<&str> = device.split(',').collect();
+
+        let mut path_str: &str = "";
+        let mut iommu_str: &str = "";
+
+        for param in params_list.iter() {
+            if param.starts_with("path=") {
+                path_str = &param[5..];
+            } else if param.starts_with("iommu=") {
+                iommu_str = &param[6..];
+            }
+        }
+
         Ok(DeviceConfig {
-            path: PathBuf::from(device),
+            path: PathBuf::from(path_str),
+            iommu: parse_iommu(iommu_str)?,
         })
     }
 }
@@ -843,7 +860,11 @@ impl VmConfig {
         if let Some(device_list) = &vm_params.devices {
             let mut device_config_list = Vec::new();
             for item in device_list.iter() {
-                device_config_list.push(DeviceConfig::parse(item)?);
+                let device_config = DeviceConfig::parse(item)?;
+                if device_config.iommu {
+                    iommu = true;
+                }
+                device_config_list.push(device_config);
             }
             devices = Some(device_config_list);
         }