runtime-rs: support iommu_platform for qemu vhost-vsock device

iommu_platform addition is controlled solely by the configuration file.

Signed-off-by: Pavel Mores <pmores@redhat.com>

src/runtime-rs/crates/hypervisor/src/qemu/cmdline_generator.rs

@@ -823,6 +823,7 @@ struct VhostVsock {
     vhostfd: tokio::fs::File,
     guest_cid: u32,
     disable_modern: bool,
+    iommu_platform: bool,
 }
 
 impl VhostVsock {
@@ -832,6 +833,7 @@ impl VhostVsock {
             vhostfd,
             guest_cid,
             disable_modern: false,
+            iommu_platform: false,
         }
     }
 
@@ -839,6 +841,11 @@ impl VhostVsock {
         self.disable_modern = disable_modern;
         self
     }
+
+    fn set_iommu_platform(&mut self, iommu_platform: bool) -> &mut Self {
+        self.iommu_platform = iommu_platform;
+        self
+    }
 }
 
 #[async_trait]
@@ -849,6 +856,9 @@ impl ToQemuParams for VhostVsock {
         if self.disable_modern {
             params.push("disable-modern=true".to_owned());
         }
+        if self.iommu_platform {
+            params.push("iommu_platform=on".to_owned());
+        }
         params.push(format!("vhostfd={}", self.vhostfd.as_raw_fd()));
         params.push(format!("guest-cid={}", self.guest_cid));
 
@@ -1282,6 +1292,10 @@ impl<'a> QemuCmdLine<'a> {
             vhost_vsock_pci.set_disable_modern(true);
         }
 
+        if self.config.device_info.enable_iommu_platform {
+            vhost_vsock_pci.set_iommu_platform(true);
+        }
+
         self.devices.push(Box::new(vhost_vsock_pci));
         Ok(())
     }