From 7fbec7113eb676ce06bc7b2d07e9d4acbd11a411 Mon Sep 17 00:00:00 2001
From: Rob Bradford <robert.bradford@intel.com>
Date: Fri, 4 Jun 2021 14:40:13 +0000
Subject: [PATCH] main, config: Add support for `--user-device`

This allows the user to specify devices that are running in a different
userspace process and communicated with vfio-user.

Signed-off-by: Rob Bradford <robert.bradford@intel.com>
---
 src/main.rs       |  9 +++++++++
 vmm/src/config.rs | 48 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/src/main.rs b/src/main.rs
index 4a2d65d5d..d2c7580eb 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -279,6 +279,14 @@ fn create_app<'a, 'b>(
                 .min_values(1)
                 .group("vm-config"),
         )
+        .arg(
+            Arg::with_name("user-device")
+                .long("user-device")
+                .help(config::UserDeviceConfig::SYNTAX)
+                .takes_value(true)
+                .min_values(1)
+                .group("vm-config"),
+        )
         .arg(
             Arg::with_name("vsock")
                 .long("vsock")
@@ -656,6 +664,7 @@ mod unit_tests {
                     iommu: false,
                 },
                 devices: None,
+                user_devices: None,
                 vsock: None,
                 iommu: false,
                 #[cfg(target_arch = "x86_64")]
diff --git a/vmm/src/config.rs b/vmm/src/config.rs
index 67f24623d..583ab63f5 100644
--- a/vmm/src/config.rs
+++ b/vmm/src/config.rs
@@ -90,6 +90,10 @@ pub enum Error {
     #[cfg(feature = "tdx")]
     // No TDX firmware
     FirmwarePathMissing,
+    /// Failed to parse userspace device
+    ParseUserDevice(OptionParserError),
+    /// Missing socket for userspace device
+    ParseUserDeviceSocketMissing,
 }
 
 #[derive(Debug)]
@@ -224,6 +228,10 @@ impl fmt::Display for Error {
             ParseRestoreSourceUrlMissing => {
                 write!(f, "Error parsing --restore: source_url missing")
             }
+            ParseUserDeviceSocketMissing => {
+                write!(f, "Error parsing --user-device: socket missing")
+            }
+            ParseUserDevice(o) => write!(f, "Error parsing --user-device: {}", o),
             Validation(v) => write!(f, "Error validating configuration: {}", v),
             #[cfg(feature = "tdx")]
             ParseTdx(o) => write!(f, "Error parsing --tdx: {}", o),
@@ -251,6 +259,7 @@ pub struct VmParams<'a> {
     pub serial: &'a str,
     pub console: &'a str,
     pub devices: Option<Vec<&'a str>>,
+    pub user_devices: Option<Vec<&'a str>>,
     pub vsock: Option<&'a str>,
     #[cfg(target_arch = "x86_64")]
     pub sgx_epc: Option<Vec<&'a str>>,
@@ -280,6 +289,7 @@ impl<'a> VmParams<'a> {
         let fs: Option<Vec<&str>> = args.values_of("fs").map(|x| x.collect());
         let pmem: Option<Vec<&str>> = args.values_of("pmem").map(|x| x.collect());
         let devices: Option<Vec<&str>> = args.values_of("device").map(|x| x.collect());
+        let user_devices: Option<Vec<&str>> = args.values_of("user-device").map(|x| x.collect());
         let vsock: Option<&str> = args.value_of("vsock");
         #[cfg(target_arch = "x86_64")]
         let sgx_epc: Option<Vec<&str>> = args.values_of("sgx-epc").map(|x| x.collect());
@@ -303,6 +313,7 @@ impl<'a> VmParams<'a> {
             serial,
             console,
             devices,
+            user_devices,
             vsock,
             #[cfg(target_arch = "x86_64")]
             sgx_epc,
@@ -1533,6 +1544,30 @@ impl DeviceConfig {
     }
 }
 
+#[derive(Clone, Debug, PartialEq, Deserialize, Serialize, Default)]
+pub struct UserDeviceConfig {
+    pub socket: PathBuf,
+    #[serde(default)]
+    pub id: Option<String>,
+}
+
+impl UserDeviceConfig {
+    pub const SYNTAX: &'static str = "Userspace device socket=<socket_path>,id=<device_id>\"";
+    pub fn parse(user_device: &str) -> Result<Self> {
+        let mut parser = OptionParser::new();
+        parser.add("socket").add("id");
+        parser.parse(user_device).map_err(Error::ParseUserDevice)?;
+
+        let socket = parser
+            .get("socket")
+            .map(PathBuf::from)
+            .ok_or(Error::ParseUserDeviceSocketMissing)?;
+
+        let id = parser.get("id");
+
+        Ok(UserDeviceConfig { socket, id })
+    }
+}
 #[derive(Clone, Debug, PartialEq, Deserialize, Serialize, Default)]
 pub struct VsockConfig {
     pub cid: u64,
@@ -1764,6 +1799,7 @@ pub struct VmConfig {
     #[serde(default = "ConsoleConfig::default_console")]
     pub console: ConsoleConfig,
     pub devices: Option<Vec<DeviceConfig>>,
+    pub user_devices: Option<Vec<UserDeviceConfig>>,
     pub vsock: Option<VsockConfig>,
     #[serde(default)]
     pub iommu: bool,
@@ -1952,6 +1988,16 @@ impl VmConfig {
             devices = Some(device_config_list);
         }
 
+        let mut user_devices: Option<Vec<UserDeviceConfig>> = None;
+        if let Some(user_device_list) = &vm_params.user_devices {
+            let mut user_device_config_list = Vec::new();
+            for item in user_device_list.iter() {
+                let user_device_config = UserDeviceConfig::parse(item)?;
+                user_device_config_list.push(user_device_config);
+            }
+            user_devices = Some(user_device_config_list);
+        }
+
         let mut vsock: Option<VsockConfig> = None;
         if let Some(vs) = &vm_params.vsock {
             let vsock_config = VsockConfig::parse(vs)?;
@@ -2017,6 +2063,7 @@ impl VmConfig {
             serial,
             console,
             devices,
+            user_devices,
             vsock,
             iommu,
             #[cfg(target_arch = "x86_64")]
@@ -2625,6 +2672,7 @@ mod tests {
                 iommu: false,
             },
             devices: None,
+            user_devices: None,
             vsock: None,
             iommu: false,
             #[cfg(target_arch = "x86_64")]