diff --git a/Cargo.lock b/Cargo.lock
index b2a87ecbfe..b8bf5efaa1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3124,6 +3124,15 @@ dependencies = [
  "zeroize",
 ]
 
+[[package]]
+name = "wasi-virtfs"
+version = "0.22.0"
+dependencies = [
+ "anyhow",
+ "cap-std",
+ "wasi-common",
+]
+
 [[package]]
 name = "wasm-encoder"
 version = "0.4.0"
diff --git a/Cargo.toml b/Cargo.toml
index 4321fda023..376a40bea8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -77,6 +77,7 @@ members = [
   "crates/wiggle/wasmtime",
   "crates/wasi-common",
   "crates/wasi-common/cap-std-sync",
+  "crates/wasi-common/virtfs",
   "examples/fib-debug/wasm",
   "examples/wasi/wasm",
   "fuzz",
diff --git a/crates/wasi-common/virtfs/Cargo.toml b/crates/wasi-common/virtfs/Cargo.toml
new file mode 100644
index 0000000000..4a760434a6
--- /dev/null
+++ b/crates/wasi-common/virtfs/Cargo.toml
@@ -0,0 +1,18 @@
+[package]
+name = "wasi-virtfs"
+version = "0.22.0"
+authors = ["The Wasmtime Project Developers"]
+description = "WASI implementation in Rust"
+license = "Apache-2.0 WITH LLVM-exception"
+categories = ["wasm"]
+keywords = ["webassembly", "wasm"]
+repository = "https://github.com/bytecodealliance/wasmtime"
+readme = "README.md"
+edition = "2018"
+include = ["src/**/*", "LICENSE" ]
+publish = false
+
+[dependencies]
+wasi-common = { path = "../", version = "0.22.0" }
+anyhow = "1.0"
+cap-std = "0.12"
diff --git a/crates/wasi-common/virtfs/src/dir.rs b/crates/wasi-common/virtfs/src/dir.rs
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/crates/wasi-common/virtfs/src/file.rs b/crates/wasi-common/virtfs/src/file.rs
new file mode 100644
index 0000000000..f76de7c85a
--- /dev/null
+++ b/crates/wasi-common/virtfs/src/file.rs
@@ -0,0 +1,84 @@
+use crate::FileInode;
+use std::any::Any;
+use std::cell::RefCell;
+use std::io;
+use std::rc::Rc;
+use wasi_common::{
+    file::{Advice, FdFlags, FileType, Filestat, WasiFile},
+    Error,
+};
+
+enum FileMode {
+    ReadOnly,
+    WriteOnly { append: bool },
+    ReadWrite,
+}
+
+pub struct File {
+    inode: Rc<RefCell<FileInode>>,
+    cursor: RefCell<usize>,
+    mode: FileMode,
+}
+
+impl File {}
+
+impl WasiFile for File {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+    fn datasync(&self) -> Result<(), Error> {
+        Ok(())
+    }
+    fn sync(&self) -> Result<(), Error> {
+        Ok(())
+    }
+    fn get_filetype(&self) -> Result<FileType, Error> {
+        todo!()
+    }
+    fn get_fdflags(&self) -> Result<FdFlags, Error> {
+        todo!()
+    }
+    fn set_fdflags(&mut self, fdflags: FdFlags) -> Result<(), Error> {
+        todo!()
+    }
+    fn get_filestat(&self) -> Result<Filestat, Error> {
+        todo!()
+    }
+    fn set_filestat_size(&self, size: u64) -> Result<(), Error> {
+        todo!()
+    }
+    fn advise(&self, _offset: u64, _len: u64, _advice: Advice) -> Result<(), Error> {
+        Ok(())
+    }
+    fn allocate(&self, offset: u64, len: u64) -> Result<(), Error> {
+        todo!()
+    }
+    fn set_times(
+        &self,
+        atime: Option<wasi_common::SystemTimeSpec>,
+        mtime: Option<wasi_common::SystemTimeSpec>,
+    ) -> Result<(), Error> {
+        todo!()
+    }
+    fn read_vectored(&self, bufs: &mut [io::IoSliceMut]) -> Result<u64, Error> {
+        todo!()
+    }
+    fn read_vectored_at(&self, bufs: &mut [io::IoSliceMut], offset: u64) -> Result<u64, Error> {
+        todo!()
+    }
+    fn write_vectored(&self, bufs: &[io::IoSlice]) -> Result<u64, Error> {
+        todo!()
+    }
+    fn write_vectored_at(&self, bufs: &[io::IoSlice], offset: u64) -> Result<u64, Error> {
+        todo!()
+    }
+    fn seek(&self, pos: std::io::SeekFrom) -> Result<u64, Error> {
+        todo!()
+    }
+    fn peek(&self, buf: &mut [u8]) -> Result<u64, Error> {
+        todo!()
+    }
+    fn num_ready_bytes(&self) -> Result<u64, Error> {
+        todo!()
+    }
+}
diff --git a/crates/wasi-common/virtfs/src/lib.rs b/crates/wasi-common/virtfs/src/lib.rs
new file mode 100644
index 0000000000..9f000ca57a
--- /dev/null
+++ b/crates/wasi-common/virtfs/src/lib.rs
@@ -0,0 +1,316 @@
+#![allow(dead_code, unused_variables, unused_imports)]
+use cap_std::time::{Duration, SystemTime};
+use std::any::Any;
+use std::cell::{Cell, Ref, RefCell, RefMut};
+use std::collections::HashMap;
+use std::convert::TryInto;
+use std::io::{Cursor, IoSlice, IoSliceMut, Read, Seek, SeekFrom, Write};
+use std::ops::Deref;
+use std::path::PathBuf;
+use std::rc::{Rc, Weak};
+use wasi_common::{
+    clocks::WasiSystemClock,
+    dir::{ReaddirCursor, ReaddirEntity, WasiDir},
+    file::{Advice, FdFlags, FileCaps, FileType, Filestat, OFlags, WasiFile},
+    Error, ErrorExt, SystemTimeSpec,
+};
+
+pub struct Filesystem {
+    root: Rc<RefCell<DirInode>>,
+    clock: Box<dyn WasiSystemClock>,
+    device_id: u64,
+    next_serial: Cell<u64>,
+}
+
+pub enum Inode {
+    Dir(Rc<RefCell<DirInode>>),
+    File(Rc<RefCell<FileInode>>),
+}
+
+pub struct DirInode {
+    fs: Weak<Filesystem>,
+    serial: u64,
+    parent: Option<Weak<RefCell<DirInode>>>,
+    contents: HashMap<String, Inode>,
+    atim: SystemTime,
+    mtim: SystemTime,
+    ctim: SystemTime,
+}
+
+impl DirInode {
+    pub fn fs(&self) -> Rc<Filesystem> {
+        Weak::upgrade(&self.fs).unwrap()
+    }
+}
+
+pub struct FileInode {
+    fs: Weak<Filesystem>,
+    serial: u64,
+    contents: Vec<u8>,
+    atim: SystemTime,
+    mtim: SystemTime,
+    ctim: SystemTime,
+}
+
+impl FileInode {
+    pub fn fs(&self) -> Rc<Filesystem> {
+        Weak::upgrade(&self.fs).unwrap()
+    }
+}
+
+enum FileMode {
+    ReadOnly,
+    WriteOnly,
+    ReadWrite,
+}
+
+pub struct File {
+    inode: Rc<RefCell<FileInode>>,
+    position: Cell<u64>,
+    fdflags: FdFlags,
+    mode: FileMode,
+}
+
+impl File {
+    fn is_read(&self) -> bool {
+        match self.mode {
+            FileMode::ReadOnly | FileMode::ReadWrite => true,
+            _ => false,
+        }
+    }
+    fn is_write(&self) -> bool {
+        match self.mode {
+            FileMode::WriteOnly | FileMode::ReadWrite => true,
+            _ => false,
+        }
+    }
+    fn is_append(&self) -> bool {
+        self.fdflags.contains(FdFlags::APPEND)
+    }
+    fn inode(&self) -> Ref<FileInode> {
+        self.inode.borrow()
+    }
+    fn inode_mut(&self) -> RefMut<FileInode> {
+        self.inode.borrow_mut()
+    }
+}
+
+impl WasiFile for File {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+    fn datasync(&self) -> Result<(), Error> {
+        Ok(())
+    }
+    fn sync(&self) -> Result<(), Error> {
+        Ok(())
+    }
+    fn get_filetype(&self) -> Result<FileType, Error> {
+        Ok(FileType::RegularFile)
+    }
+    fn get_fdflags(&self) -> Result<FdFlags, Error> {
+        Ok(self.fdflags)
+    }
+    fn set_fdflags(&mut self, fdflags: FdFlags) -> Result<(), Error> {
+        self.fdflags = fdflags;
+        Ok(())
+    }
+    fn get_filestat(&self) -> Result<Filestat, Error> {
+        let inode = self.inode();
+        let fs = inode.fs();
+        Ok(Filestat {
+            device_id: fs.device_id,
+            inode: inode.serial,
+            filetype: self.get_filetype().unwrap(),
+            nlink: 0,
+            size: inode.contents.len() as u64,
+            atim: Some(inode.atim.into_std()),
+            ctim: Some(inode.ctim.into_std()),
+            mtim: Some(inode.mtim.into_std()),
+        })
+    }
+    fn set_filestat_size(&self, size: u64) -> Result<(), Error> {
+        let mut inode = self.inode.borrow_mut();
+        inode.contents.resize(size.try_into()?, 0);
+        Ok(())
+    }
+    fn advise(&self, _offset: u64, _len: u64, _advice: Advice) -> Result<(), Error> {
+        Ok(())
+    }
+    fn allocate(&self, offset: u64, len: u64) -> Result<(), Error> {
+        let mut inode = self.inode.borrow_mut();
+        let size = offset.checked_add(len).ok_or_else(|| Error::overflow())?;
+        if size > inode.contents.len() as u64 {
+            inode.contents.resize(size.try_into()?, 0);
+        }
+        Ok(())
+    }
+    fn set_times(
+        &self,
+        atime: Option<SystemTimeSpec>,
+        mtime: Option<SystemTimeSpec>,
+    ) -> Result<(), Error> {
+        let newtime = |s| match s {
+            SystemTimeSpec::SymbolicNow => self.inode().fs().clock.now(Duration::from_secs(0)),
+            SystemTimeSpec::Absolute(t) => t,
+        };
+        let mut inode = self.inode.borrow_mut();
+        if let Some(atim) = atime {
+            inode.atim = newtime(atim);
+        }
+        if let Some(mtim) = mtime {
+            inode.mtim = newtime(mtim);
+        }
+        Ok(())
+    }
+    fn read_vectored(&self, bufs: &mut [IoSliceMut]) -> Result<u64, Error> {
+        if !self.is_read() {
+            return Err(Error::badf());
+        }
+        let inode = self.inode();
+        let mut cursor = Cursor::new(inode.contents.as_slice());
+        cursor.set_position(self.position.get());
+        let nbytes = cursor.read_vectored(bufs)?;
+        self.position.set(cursor.position());
+        Ok(nbytes.try_into()?)
+    }
+    fn read_vectored_at(&self, bufs: &mut [IoSliceMut], offset: u64) -> Result<u64, Error> {
+        if !self.is_read() {
+            return Err(Error::badf());
+        }
+        let inode = self.inode();
+        let mut cursor = Cursor::new(inode.contents.as_slice());
+        cursor.set_position(offset);
+        let nbytes = cursor.read_vectored(bufs)?;
+        Ok(nbytes.try_into()?)
+    }
+    fn write_vectored(&self, bufs: &[IoSlice]) -> Result<u64, Error> {
+        if !self.is_write() {
+            return Err(Error::badf());
+        }
+        let mut inode = self.inode_mut();
+        let mut cursor = Cursor::new(&mut inode.contents);
+        cursor.set_position(self.position.get());
+        let nbytes = cursor.write_vectored(bufs)?;
+        self.position.set(cursor.position());
+        Ok(nbytes.try_into()?)
+    }
+    fn write_vectored_at(&self, bufs: &[IoSlice], offset: u64) -> Result<u64, Error> {
+        if !self.is_write() || self.is_append() {
+            return Err(Error::badf());
+        }
+        let mut inode = self.inode_mut();
+        let mut cursor = Cursor::new(&mut inode.contents);
+        cursor.set_position(offset);
+        let nbytes = cursor.write_vectored(bufs)?;
+        self.position.set(cursor.position());
+        Ok(nbytes.try_into()?)
+    }
+    fn seek(&self, pos: SeekFrom) -> Result<u64, Error> {
+        if self.is_append() {
+            match pos {
+                SeekFrom::Current(0) => return Ok(self.position.get()),
+                _ => return Err(Error::badf()),
+            }
+        }
+        let inode = self.inode();
+        let mut cursor = Cursor::new(inode.contents.as_slice());
+        cursor.set_position(self.position.get());
+        cursor.seek(pos)?;
+        let new_position = cursor.position();
+        self.position.set(new_position);
+        Ok(new_position)
+    }
+    fn peek(&self, buf: &mut [u8]) -> Result<u64, Error> {
+        if !self.is_read() {
+            return Err(Error::badf());
+        }
+        let inode = self.inode();
+        let mut cursor = Cursor::new(inode.contents.as_slice());
+        cursor.set_position(self.position.get());
+        let nbytes = cursor.read(buf)?;
+        Ok(nbytes.try_into()?)
+    }
+    fn num_ready_bytes(&self) -> Result<u64, Error> {
+        if !self.is_read() {
+            return Err(Error::badf());
+        }
+        let len = self.inode().contents.len() as u64;
+        Ok(len - self.position.get())
+    }
+}
+
+pub struct Dir;
+
+impl Dir {}
+
+impl WasiDir for Dir {
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+    fn open_file(
+        &self,
+        symlink_follow: bool,
+        path: &str,
+        oflags: OFlags,
+        read: bool,
+        write: bool,
+        fdflags: FdFlags,
+    ) -> Result<Box<dyn WasiFile>, Error> {
+        todo!()
+    }
+
+    fn open_dir(&self, symlink_follow: bool, path: &str) -> Result<Box<dyn WasiDir>, Error> {
+        todo!()
+    }
+
+    fn create_dir(&self, path: &str) -> Result<(), Error> {
+        todo!()
+    }
+    fn readdir(
+        &self,
+        cursor: ReaddirCursor,
+    ) -> Result<Box<dyn Iterator<Item = Result<(ReaddirEntity, String), Error>>>, Error> {
+        todo!()
+    }
+
+    fn symlink(&self, src_path: &str, dest_path: &str) -> Result<(), Error> {
+        todo!()
+    }
+    fn remove_dir(&self, path: &str) -> Result<(), Error> {
+        todo!()
+    }
+
+    fn unlink_file(&self, path: &str) -> Result<(), Error> {
+        todo!()
+    }
+    fn read_link(&self, path: &str) -> Result<PathBuf, Error> {
+        todo!()
+    }
+    fn get_filestat(&self) -> Result<Filestat, Error> {
+        todo!()
+    }
+    fn get_path_filestat(&self, path: &str, follow_symlinks: bool) -> Result<Filestat, Error> {
+        todo!()
+    }
+    fn rename(&self, src_path: &str, dest_dir: &dyn WasiDir, dest_path: &str) -> Result<(), Error> {
+        todo!()
+    }
+    fn hard_link(
+        &self,
+        src_path: &str,
+        target_dir: &dyn WasiDir,
+        target_path: &str,
+    ) -> Result<(), Error> {
+        todo!()
+    }
+    fn set_times(
+        &self,
+        path: &str,
+        atime: Option<wasi_common::SystemTimeSpec>,
+        mtime: Option<wasi_common::SystemTimeSpec>,
+        follow_symlinks: bool,
+    ) -> Result<(), Error> {
+        todo!()
+    }
+}