diff --git a/Cargo.toml b/Cargo.toml
index ddd3923..edff375 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,7 +10,7 @@ members = [
 ]
 
 [workspace.package]
-version = "19.0.0"
+version = "21.0.0"
 authors = ["The Blockless Project Developers"]
 edition = "2021"
 
@@ -21,13 +21,13 @@ wasi-common = {path = "crates/wasi-common"}
 [workspace.dependencies]
 tempfile = "3.1.0"
 libc = "0.2.60"
-wasmtime = "19.0.0"
-wasmtime-wasi = "19.0.0"
-wiggle-generate = "19.0.0"
-wasmtime-wasi-threads = "19.0.0" 
-wasi-common = { path = "crates/wasi-common", version="19.0.0" }
+wasmtime = "21.0.0"
+wasmtime-wasi = "21.0.0"
+wiggle-generate = "21.0.0"
+wasmtime-wasi-threads = "21.0.0" 
+wasi-common = { path = "crates/wasi-common", version="21.0.0" }
 # witx dependency by wiggle
-wiggle = "19.0.0"
+wiggle = "21.0.0"
 witx = "0.9.1"
 
 anyhow = "1.0.22"
diff --git a/blockless/src/context.rs b/blockless/src/context.rs
index f394c7d..e4442aa 100644
--- a/blockless/src/context.rs
+++ b/blockless/src/context.rs
@@ -1,12 +1,13 @@
 use std::sync::{Arc, Mutex};
 
+use wasmtime_wasi::preview1::WasiP1Ctx;
 use wasmtime_wasi_threads::WasiThreadsCtx;
 
 #[derive(Clone)]
 pub(crate) struct BlocklessContext {
     pub(crate) preview1_ctx: Option<wasi_common::WasiCtx>,
 
-    pub(crate) preview2_ctx: Option<Arc<Mutex<wasmtime_wasi::WasiP1Ctx>>>,
+    pub(crate) preview2_ctx: Option<Arc<Mutex<WasiP1Ctx>>>,
 
     pub(crate) wasi_threads: Option<Arc<WasiThreadsCtx<BlocklessContext>>>,
 }
@@ -22,7 +23,7 @@ impl Default for BlocklessContext {
 }
 
 impl BlocklessContext {
-    pub(crate) fn preview2_ctx(&mut self) -> &mut wasmtime_wasi::WasiP1Ctx {
+    pub(crate) fn preview2_ctx(&mut self) -> &mut WasiP1Ctx {
         let ctx = self.preview2_ctx.as_mut().unwrap();
         Arc::get_mut(ctx)
             .expect("wasmtime_wasi was not compatiable threads")
diff --git a/bls-runtime/src/macros.rs b/bls-runtime/src/macros.rs
index 06c22a9..1015619 100644
--- a/bls-runtime/src/macros.rs
+++ b/bls-runtime/src/macros.rs
@@ -1,4 +1,3 @@
-#[macro_export]
 macro_rules! plog {
     ($level: expr, $($args:tt)+) => {{
         crate::plog::plog($level, std::format_args!($($args)+))
@@ -6,10 +5,9 @@ macro_rules! plog {
 }
 
 /// export the perror macro for log the error
-#[macro_export]
 macro_rules! perror {
     ($($args:tt)+) => {{
-        crate::plog!(log::Level::Error, $($args)+)
+        plog!(log::Level::Error, $($args)+)
     }};
 
     () => {{
@@ -19,7 +17,7 @@ macro_rules! perror {
 }
 
 /// export the pinfo macro for log the info
-#[macro_export]
+#[allow(unused_macros)]
 macro_rules! pinfo {
     ($($args:tt)+) => {{
         crate::plog!(log::Level::Info, $($args)+)
diff --git a/bls-runtime/src/main.rs b/bls-runtime/src/main.rs
index 9ada853..e6da38c 100644
--- a/bls-runtime/src/main.rs
+++ b/bls-runtime/src/main.rs
@@ -1,6 +1,7 @@
 mod cli_clap;
 mod config;
 mod error;
+#[macro_use]
 mod macros;
 mod plog;
 mod v86;
diff --git a/crates/wasi-common/src/ctx.rs b/crates/wasi-common/src/ctx.rs
index 9cf2232..29caad9 100644
--- a/crates/wasi-common/src/ctx.rs
+++ b/crates/wasi-common/src/ctx.rs
@@ -15,7 +15,7 @@ use std::sync::{Arc, Mutex};
 /// the file descriptor table. This wrapper is only necessary due to the
 /// signature of `fd_fdstat_set_flags`; if that changes, there are a variety of
 /// improvements that can be made (TODO:
-/// https://github.com/bytecodealliance/wasmtime/issues/5643).
+/// <https://github.com/bytecodealliance/wasmtime/issues/5643)>.
 #[derive(Clone)]
 pub struct WasiCtx(Arc<WasiCtxInner>);
 
diff --git a/crates/wasi-common/src/lib.rs b/crates/wasi-common/src/lib.rs
index c790f48..dff9a6e 100644
--- a/crates/wasi-common/src/lib.rs
+++ b/crates/wasi-common/src/lib.rs
@@ -68,6 +68,7 @@
 //! interface to plug in its own implementations of each of these resources.
 
 #![warn(clippy::cast_sign_loss)]
+#![cfg_attr(docsrs, feature(doc_cfg))]
 
 pub mod clocks;
 mod ctx;
@@ -79,15 +80,14 @@ pub mod random;
 pub mod sched;
 pub mod snapshots;
 mod string_array;
+#[cfg_attr(docsrs, doc(cfg(feature = "sync")))]
 #[cfg(feature = "sync")]
 pub mod sync;
 pub mod table;
+#[cfg_attr(docsrs, doc(cfg(feature = "tokio")))]
 #[cfg(feature = "tokio")]
 pub mod tokio;
 
-pub mod blockless;
-pub use blockless::*;
-
 pub use cap_rand::RngCore;
 pub use clocks::{SystemTimeSpec, WasiClocks, WasiMonotonicClock, WasiSystemClock};
 pub use ctx::WasiCtx;
@@ -98,6 +98,12 @@ pub use sched::{Poll, WasiSched};
 pub use string_array::{StringArray, StringArrayError};
 pub use table::Table;
 
+mod blockless;
+pub use blockless::{
+    BlocklessConfig, BlocklessConfigVersion, BlocklessModule, DriverConfig, LoggerLevel,
+    ModuleType, Permission, Stderr, Stdout,
+};
+
 // The only difference between these definitions for sync vs async is whether
 // the wasmtime::Funcs generated are async (& therefore need an async Store and an executor to run)
 // or whether they have an internal "dummy executor" that expects the implementation of all
@@ -153,6 +159,7 @@ macro_rules! define_wasi {
 /// Note: this function is designed for usage where it is acceptable for
 /// Wasmtime failures to terminate the parent process, such as in the Wasmtime
 /// CLI; this would not be suitable for use in multi-tenant embeddings.
+#[cfg_attr(docsrs, doc(cfg(feature = "exit")))]
 #[cfg(feature = "exit")]
 pub fn maybe_exit_on_error(e: anyhow::Error) -> anyhow::Error {
     use std::process;
diff --git a/crates/wasi-common/src/snapshots/preview_1.rs b/crates/wasi-common/src/snapshots/preview_1.rs
index 329e5ab..a583126 100644
--- a/crates/wasi-common/src/snapshots/preview_1.rs
+++ b/crates/wasi-common/src/snapshots/preview_1.rs
@@ -340,13 +340,17 @@ impl wasi_snapshot_preview1::WasiSnapshotPreview1 for WasiCtx {
                 return Ok(0);
             }
         } else {
-            // Convert all of the unsafe guest slices to safe ones--this uses
-            // Wiggle's internal borrow checker to ensure no overlaps. We assume
-            // here that, because the memory is not shared, there are no other
-            // threads to access it while it is written to.
+            // Convert the first unsafe guest slice into a safe one--Wiggle
+            // can only track mutable borrows for an entire region, and converting
+            // all guest pointers to slices would cause a runtime borrow-checking
+            // error. As read is allowed to return less than the requested amount,
+            // it's valid (though not as efficient) for us to only perform the
+            // read of the first buffer.
             let mut guest_slices: Vec<wiggle::GuestSliceMut<u8>> = iovs
                 .into_iter()
+                .filter(|iov| iov.len() > 0)
                 .map(|iov| Ok(iov.as_slice_mut()?.unwrap()))
+                .take(1)
                 .collect::<Result<_, Error>>()?;
 
             // Read directly into the Wasm memory.
@@ -417,13 +421,15 @@ impl wasi_snapshot_preview1::WasiSnapshotPreview1 for WasiCtx {
                 return Ok(0);
             }
         } else {
-            // Convert all of the unsafe guest slices to safe ones--this uses
-            // Wiggle's internal borrow checker to ensure no overlaps. We assume
-            // here that, because the memory is not shared, there are no other
-            // threads to access it while it is written to.
+            // Convert unsafe guest slices to safe ones -- this uses Wiggle's
+            // internal borrow checker to ensure no overlaps. Note that borrow
+            // checking is coarse at this time so at most one non-empty slice is
+            // chosen.
             let mut guest_slices: Vec<wiggle::GuestSliceMut<u8>> = iovs
                 .into_iter()
+                .filter(|iov| iov.len() > 0)
                 .map(|iov| Ok(iov.as_slice_mut()?.unwrap()))
+                .take(1)
                 .collect::<Result<_, Error>>()?;
 
             // Read directly into the Wasm memory.