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

Having the virtual IOMMU created with --iommu is one thing, but we also
need a way to decide if a virtio-net device should be attached to this
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>

src/main.rs

@@ -135,7 +135,8 @@ fn main() {
                 .long("net")
                 .help(
                     "Network parameters \"tap=<if_name>,\
-                     ip=<ip_addr>,mask=<net_mask>,mac=<mac_addr>\"",
+                     ip=<ip_addr>,mask=<net_mask>,mac=<mac_addr>,\
+                     iommu=on|off\"",
                 )
                 .takes_value(true)
                 .min_values(1)

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

@@ -244,6 +244,9 @@ components:
           type: string
         mac:
           type: string
+        iommu:
+          type: boolean
+          default: false
 
     RngConfig:
       required:

vmm/src/config.rs

@@ -259,6 +259,8 @@ pub struct NetConfig {
     pub ip: Ipv4Addr,
     pub mask: Ipv4Addr,
     pub mac: MacAddr,
+    #[serde(default)]
+    pub iommu: bool,
 }
 
 impl NetConfig {
@@ -270,6 +272,7 @@ impl NetConfig {
         let mut ip_str: &str = "";
         let mut mask_str: &str = "";
         let mut mac_str: &str = "";
+        let mut iommu_str: &str = "";
 
         for param in params_list.iter() {
             if param.starts_with("tap=") {
@@ -280,6 +283,8 @@ impl NetConfig {
                 mask_str = &param[5..];
             } else if param.starts_with("mac=") {
                 mac_str = &param[4..];
+            } else if param.starts_with("iommu=") {
+                iommu_str = &param[6..];
             }
         }
 
@@ -287,6 +292,7 @@ impl NetConfig {
         let mut ip: Ipv4Addr = Ipv4Addr::new(192, 168, 249, 1);
         let mut mask: Ipv4Addr = Ipv4Addr::new(255, 255, 255, 0);;
         let mut mac: MacAddr = MacAddr::local_random();
+        let iommu = parse_iommu(iommu_str)?;
 
         if !tap_str.is_empty() {
             tap = Some(tap_str.to_string());
@@ -301,7 +307,13 @@ impl NetConfig {
             mac = MacAddr::parse_str(mac_str).map_err(Error::ParseNetMacParam)?;
         }
 
-        Ok(NetConfig { tap, ip, mask, mac })
+        Ok(NetConfig {
+            tap,
+            ip,
+            mask,
+            mac,
+            iommu,
+        })
     }
 }
 
@@ -731,7 +743,11 @@ impl VmConfig {
         if let Some(net_list) = &vm_params.net {
             let mut net_config_list = Vec::new();
             for item in net_list.iter() {
-                net_config_list.push(NetConfig::parse(item)?);
+                let net_config = NetConfig::parse(item)?;
+                if net_config.iommu {
+                    iommu = true;
+                }
+                net_config_list.push(net_config);
             }
             net = Some(net_config_list);
         }