feat(xtask): add support for custom VMM and Hermit args

xtask/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2024"
 
 [features]
 default = ["ci"]
-ci = ["dep:libc", "dep:ovmf-prebuilt", "dep:sysinfo", "dep:ureq", "dep:vsock", "dep:wait-timeout"]
+ci = ["dep:libc", "dep:ovmf-prebuilt", "dep:shlex", "dep:sysinfo", "dep:ureq", "dep:vsock", "dep:wait-timeout"]
 
 [dependencies]
 anyhow = "1.0"
@@ -14,6 +14,7 @@ goblin = { version = "0.10", default-features = false, features = ["archive", "e
 home = "0.5"
 libc = { version = "0.2", optional = true }
 ovmf-prebuilt = { version = "0.2", optional = true }
+shlex = { version = "2", optional = true }
 sysinfo = { version = "0.39", optional = true }
 ureq = { version = "3", default-features = false, features = ["rustls"], optional = true }
 vsock = { version = "0.5", optional = true }

xtask/src/ci/firecracker.rs

@@ -5,22 +5,32 @@ use anyhow::Result;
 use clap::Args;
 use xshell::cmd;
 
+use crate::ci;
+
 /// Run image on Firecracker.
 #[derive(Args)]
 pub struct Firecracker {
 	/// Run Firecracker using `sudo`.
 	#[arg(long)]
 	sudo: bool,
+
+	/// Arguments to pass to Firecracker and Hermit, separated by another `--`.
+	#[arg(last = true)]
+	firecracker_and_hermit_args: Vec<String>,
 }
 
 impl Firecracker {
 	pub fn run(self, image: &Path, smp: usize) -> Result<()> {
 		let sh = crate::sh()?;
 
+		let (firecracker_args, hermit_args) = ci::split_args(&self.firecracker_and_hermit_args);
+		let quoted_hermit_args = shlex::try_join(hermit_args.iter().map(AsRef::as_ref))?;
+
 		let config = format!(
 			include_str!("firecracker_vm_config.json"),
 			kernel_image_path = "hermit-loader-x86_64-fc",
 			initrd_path = image.display(),
+			boot_args = quoted_hermit_args,
 			vcpu_count = smp,
 		);
 		eprintln!("firecracker config");
@@ -39,7 +49,7 @@ impl Firecracker {
 		for run in 1.. {
 			let log_path = Path::new("firecracker.log");
 			sh.write_file(log_path, "")?;
-			let res = cmd!(sh, "{program} {arg...} --no-api --config-file {config_path} --log-path {log_path} --level Info --show-level --show-log-origin").run();
+			let res = cmd!(sh, "{program} {arg...} --no-api --config-file {config_path} --log-path {log_path} --level Info --show-level --show-log-origin {firecracker_args...}").run();
 			let log = sh.read_file(log_path)?;
 
 			eprintln!("firecracker log");

xtask/src/ci/firecracker_vm_config.json

@@ -2,7 +2,7 @@
   "boot-source": {{
     "kernel_image_path": "{kernel_image_path}",
     "initrd_path": "{initrd_path}",
-    "boot_args": ""
+    "boot_args": "{boot_args}"
   }},
   "drives": [],
   "machine-config": {{

xtask/src/ci/mod.rs

@@ -29,6 +29,13 @@ fn in_ci() -> bool {
 	std::env::var_os("CI") == Some("true".into())
 }
 
+fn split_args<T: PartialEq<str>>(args: &[T]) -> (&[T], &[T]) {
+	match args.iter().position(|arg| arg == "--") {
+		Some(index) => (&args[..index], &args[index + 1..]),
+		None => (args, &[]),
+	}
+}
+
 pub fn parent_root() -> &'static Path {
 	crate::project_root().parent().unwrap()
 }

xtask/src/ci/qemu.rs

@@ -14,6 +14,7 @@ use wait_timeout::ChildExt as _;
 use xshell::cmd;
 
 use crate::arch::Arch;
+use crate::ci;
 
 const DEFAULT_GUEST_IP: IpAddr = IpAddr::V4(Ipv4Addr::new(10, 0, 5, 3));
 
@@ -51,6 +52,10 @@ pub struct Qemu {
 	/// Use a TAP device for networking.
 	#[arg(long)]
 	tap: bool,
+
+	/// Arguments to pass to QEMU and Hermit, separated by another `--`.
+	#[arg(last = true)]
+	qemu_and_hermit_args: Vec<String>,
 }
 
 #[derive(ValueEnum, PartialEq, Eq, Clone, Copy)]
@@ -101,6 +106,8 @@ impl Qemu {
 	) -> Result<()> {
 		let sh = crate::sh()?;
 
+		let (qemu_args, hermit_args) = ci::split_args(&self.qemu_and_hermit_args);
+
 		let virtiofsd = self
 			.devices
 			.iter()
@@ -136,7 +143,8 @@ impl Qemu {
 			.args(&["-m".to_owned(), format!("{memory}M")])
 			.args(&["-global", "virtio-mmio.force-legacy=off"])
 			.args(self.device_args(memory))
-			.args(self.cmdline_args(image_name));
+			.args(qemu_args)
+			.args(self.cmdline_args(image_name, hermit_args));
 
 		eprintln!("$ {qemu}");
 		let mut qemu = Command::from(qemu);
@@ -482,10 +490,14 @@ impl Qemu {
 			.collect()
 	}
 
-	fn cmdline_args(&self, image_name: &str) -> Vec<String> {
+	fn cmdline_args(&self, image_name: &str, hermit_args: &[String]) -> Vec<String> {
+		let (user_kernel_args, user_app_args) = ci::split_args(hermit_args);
+
 		let mut cmdline = self.kernel_args();
+		cmdline.extend(user_kernel_args.iter().cloned());
 
 		let mut app_args = self.app_args(image_name);
+		app_args.extend(user_app_args.iter().cloned());
 		if !app_args.is_empty() {
 			cmdline.push("--".to_owned());
 			cmdline.append(&mut app_args);

xtask/src/ci/uhyve.rs

@@ -11,20 +11,29 @@ pub struct Uhyve {
 	/// Run Uhyve using `sudo`.
 	#[arg(long)]
 	sudo: bool,
+
+	/// Arguments to pass to Uhyve and Hermit, separated by another `--`.
+	#[arg(last = true)]
+	uhyve_and_hermit_args: Vec<String>,
 }
 
 impl Uhyve {
 	pub fn run(self, image: &Path, smp: usize) -> Result<()> {
 		let sh = crate::sh()?;
 
+		let uhyve_and_hermit_args = &self.uhyve_and_hermit_args[..];
+
 		let uhyve = env::var("UHYVE").unwrap_or_else(|_| "uhyve".to_owned());
 		let program = if self.sudo { "sudo" } else { uhyve.as_str() };
 		let arg = self.sudo.then_some(uhyve.as_str());
 		let smp_arg = format!("--cpu-count={smp}");
 
-		cmd!(sh, "{program} {arg...} {smp_arg} {image}")
-			.env("RUST_LOG", "debug")
-			.run()?;
+		cmd!(
+			sh,
+			"{program} {arg...} {smp_arg} {image} {uhyve_and_hermit_args...}"
+		)
+		.env("RUST_LOG", "debug")
+		.run()?;
 
 		Ok(())
 	}