crosvm: config: Make --pmem-ext2 Linux specific flag

Although ext2 crate works only on Linux, --pmem-ext2 was exposed on
Windows platform. So, we make this flag available only on
Linux family.

BUG=b:329359333
TEST=run crosvm with `--pmem-ext2 /path/to/crosvm/ext2/src/`

Change-Id: I25ee0c27727dce04efa803a69085f24020f17c68
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/5633330
Reviewed-by: Junichi Uekawa <uekawa@chromium.org>
Commit-Queue: Keiichi Watanabe <keiichiw@chromium.org>

ext2/src/lib.rs

@@ -4,7 +4,7 @@
 
 //! This crate provides a logic for creating an ext2 filesystem on memory.
 
-#![cfg(target_os = "linux")]
+#![cfg(any(target_os = "android", target_os = "linux"))]
 #![deny(missing_docs)]
 
 mod arena;

src/crosvm/cmdline.rs

@@ -9,6 +9,7 @@ cfg_if::cfg_if! {
 
         use crate::crosvm::sys::config::VfioOption;
         use crate::crosvm::sys::config::SharedDir;
+        use crate::crosvm::sys::config::PmemExt2Option;
     }
 }
 
@@ -94,7 +95,6 @@ use crate::crosvm::config::HypervisorKind;
 use crate::crosvm::config::InputDeviceOption;
 use crate::crosvm::config::IrqChipKind;
 use crate::crosvm::config::MemOptions;
-use crate::crosvm::config::PmemExt2Option;
 use crate::crosvm::config::TouchDeviceOption;
 use crate::crosvm::config::VhostUserFrontendOption;
 use crate::crosvm::config::VhostUserFsOption;
@@ -1838,6 +1838,7 @@ pub struct RunCommand {
     /// path to a disk image
     pmem_device: Vec<DiskOption>,
 
+    #[cfg(any(target_os = "android", target_os = "linux"))]
     #[argh(option, arg_name = "PATH")]
     #[serde(default)]
     #[merge(strategy = append)]
@@ -2898,7 +2899,10 @@ impl TryFrom<RunCommand> for super::config::Config {
             }
         }
 
-        cfg.pmem_ext2 = cmd.pmem_ext2;
+        #[cfg(any(target_os = "android", target_os = "linux"))]
+        {
+            cfg.pmem_ext2 = cmd.pmem_ext2;
+        }
 
         #[cfg(feature = "pvclock")]
         {

src/crosvm/config.rs

@@ -386,12 +386,6 @@ pub struct FileBackedMappingParameters {
     pub align: bool,
 }
 
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, serde_keyvalue::FromKeyValues)]
-#[serde(deny_unknown_fields, rename_all = "kebab-case")]
-pub struct PmemExt2Option {
-    pub path: PathBuf,
-}
-
 fn parse_hex_or_decimal(maybe_hex_string: &str) -> Result<u64, String> {
     // Parse string starting with 0x as hex and others as numbers.
     if let Some(hex_string) = maybe_hex_string.strip_prefix("0x") {
@@ -801,7 +795,8 @@ pub struct Config {
     #[cfg(feature = "plugin")]
     pub plugin_mounts: Vec<crate::crosvm::plugin::BindMount>,
     pub plugin_root: Option<PathBuf>,
-    pub pmem_ext2: Vec<PmemExt2Option>,
+    #[cfg(any(target_os = "android", target_os = "linux"))]
+    pub pmem_ext2: Vec<crate::crosvm::sys::config::PmemExt2Option>,
     pub pmems: Vec<PmemOption>,
     #[cfg(feature = "process-invariants")]
     pub process_invariants_data_handle: Option<u64>,
@@ -1023,6 +1018,7 @@ impl Default for Config {
             #[cfg(feature = "plugin")]
             plugin_mounts: Vec::new(),
             plugin_root: None,
+            #[cfg(any(target_os = "android", target_os = "linux"))]
             pmem_ext2: Vec::new(),
             pmems: Vec::new(),
             #[cfg(feature = "process-invariants")]
@@ -2416,19 +2412,4 @@ mod tests {
             .unwrap_err()
             .contains("swap-interval parameter can only be set for writable pmem device"));
     }
-
-    #[test]
-    fn parse_pmem_ext2() {
-        let config: Config = crate::crosvm::cmdline::RunCommand::from_args(
-            &[],
-            &["--pmem-ext2", "/path/to/dir", "/dev/null"],
-        )
-        .unwrap()
-        .try_into()
-        .unwrap();
-
-        let opt = config.pmem_ext2.first().unwrap();
-
-        assert_eq!(opt.path, PathBuf::from("/path/to/dir"));
-    }
 }

src/crosvm/sys/linux/config.rs

@@ -220,6 +220,12 @@ impl FromStr for SharedDir {
     }
 }
 
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq, serde_keyvalue::FromKeyValues)]
+#[serde(deny_unknown_fields, rename_all = "kebab-case")]
+pub struct PmemExt2Option {
+    pub path: PathBuf,
+}
+
 #[cfg(test)]
 mod tests {
     use std::path::Path;
@@ -761,4 +767,19 @@ mod tests {
                 .use_dax
         );
     }
+
+    #[test]
+    fn parse_pmem_ext2() {
+        let config: Config = crate::crosvm::cmdline::RunCommand::from_args(
+            &[],
+            &["--pmem-ext2", "/path/to/dir", "/dev/null"],
+        )
+        .unwrap()
+        .try_into()
+        .unwrap();
+
+        let opt = config.pmem_ext2.first().unwrap();
+
+        assert_eq!(opt.path, PathBuf::from("/path/to/dir"));
+    }
 }

src/crosvm/sys/linux/device_helpers.rs

@@ -88,10 +88,10 @@ use sync::Mutex;
 use vm_control::api::VmMemoryClient;
 use vm_memory::GuestAddress;
 
-use crate::crosvm::config::PmemExt2Option;
 use crate::crosvm::config::PmemOption;
 use crate::crosvm::config::VhostUserFrontendOption;
 use crate::crosvm::config::VhostUserFsOption;
+use crate::crosvm::sys::config::PmemExt2Option;
 
 pub enum TaggedControlTube {
     Fs(Tube),