add option to specify the mount point of uhyve's filesystem

src/env.rs

@@ -81,6 +81,10 @@ impl Default for Cli {
 					let gateway = expect_arg(words.next(), word.as_str());
 					env_vars.insert(String::from("HERMIT_GATEWAY"), gateway);
 				}
+				"-mount" => {
+					let gateway = expect_arg(words.next(), word.as_str());
+					env_vars.insert(String::from("UHYVE_MOUNT"), gateway);
+				}
 				"--" => args.extend(&mut words),
 				_ if image_path.is_none() => image_path = Some(word),
 				word => panic!(

src/fs/uhyve.rs

@@ -317,12 +317,12 @@ impl VfsNode for UhyveDirectory {
 pub(crate) fn init() {
 	info!("Try to initialize uhyve filesystem");
 	if is_uhyve() {
-		let mount_point = "/host".to_string();
+		let mount_point = hermit_var_or!("UHYVE_MOUNT", "/host").to_string();
 		info!("Mounting virtio-fs at {}", mount_point);
 		fs::FILESYSTEM
 			.get()
 			.unwrap()
-			.mount(mount_point.as_str(), Box::new(UhyveDirectory::new()))
+			.mount(&mount_point, Box::new(UhyveDirectory::new()))
 			.expect("Mount failed. Duplicate mount_point?");
 	}
 }