danbugs · Nov 5, 2026 · Nov 5, 2026 · Nov 5, 2026 · Nov 5, 2026 · Nov 5, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -4,6 +4,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 ## [Prerelease] - Unreleased
 
+## [v0.21.0]
+
 ### Added
 
 - `AppSandbox::snapshot_with_scratch_mb` takes a snapshot with another scratch size, which the sandbox continues on and a restore of the snapshot gets: boot with what unpacking the rootfs needs, then run guest function calls with what they need, less or more. The snapshot records the size (`snapshot_scratch_mb`), as do later snapshots of the sandbox. A size too small for the kernel makes the sandbox's next entry, the restore, and a boot from the snapshot fail (restoring a snapshot that fits recovers the sandbox). A guest function call that runs out of scratch ends with its process killed (status 137 with a single-process driver, such as python's) or the guest aborted, depending on what runs out first. A restore recovers the sandbox.
@@ -12,10 +14,16 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 ### Changed
 
-- The host places the transport arena at a fixed address below the top of scratch, so a snapshot keeps it when restored with a different scratch size. Snapshots saved by an earlier release are refused: save them again. A native Unikraft kernel (`--kernel`, `SandboxBuilder::from_kernel`) built against an earlier `plat/hyperlight` can allocate over the arena: rebuild it against this kernel tree.
+- Snapshots saved by v0.20.1 and earlier releases are refused (the kernel, the host's memory layout and the hyperlight-host dependency changed); save them again.
+- The host places the transport arena at a fixed address below the top of scratch, so a snapshot keeps it when restored with a different scratch size.
+- `hyperlight-host` and `hyperlight-common` move to 0.19. Hyperlight 0.19 gives the guest no heap region (hyperlight-dev/hyperlight#1968): the memory the guest allocates from is scratch. The kernel took its 1 MiB boot stack from that region, and now keeps it in its own image. The re-exported `hyperlight_host` is 0.19: its `SandboxConfiguration::set_heap_size`, `SandboxConfiguration::DEFAULT_HEAP_SIZE`, `SandboxBuilder::heap_size` and `SandboxBuilder::get_heap_size` (hyperlight's builder, not hluk's) are gone (size scratch instead), and `HostFunctions`, `Snapshot` (and what takes or returns one), `Error::Hyperlight`, and the interrupt handle `AppSandbox::interrupt_handle` returns and `SandboxBuilder::on_interrupt_handle` hands over are 0.19's types. For Hyperlight 0.19's other breaking changes (among them `PtRootFinder` gets a `SnapshotMemoryReader` and returns `Result<Vec<u64>>`, `Sandbox::snapshot` removes `map_region` and `map_file_cow` regions, snapshot ABI 9), see [its CHANGELOG](https://github.com/hyperlight-dev/hyperlight/blob/v0.19.0/CHANGELOG.md). A native Unikraft kernel (`--kernel`, `SandboxBuilder::from_kernel`) built against an earlier `plat/hyperlight` no longer boots: rebuild it against this kernel tree. `plat/hyperlight` now selects paging and refuses a build without a boot allocator, and the guest crashes if the canary word at the bottom of its 1 MiB boot stack (the init thread's, which also runs a native `main()` without `LIBUKBOOT_MAINTHREAD`) is found overwritten at the end of boot, at the start of an entry from the host, at the end of a call's entry, or at a shutdown.
+- A `NetworkFilter`'s `allows` is asked at each send on a connected UDP socket rather than at its `connect()`, as it already was at an unconnected `sendto()`; a TCP connect is asked about as before. A `BlockList` looks its names up at those sends too, rather than at the UDP `connect()`.
+- CI: on the Linux arm64 runner, a failure of the `http-express` demo or of the `smolagents` or `mcp` integration jobs no longer fails the run: under nested virtualization their guest's vCPU wedges (hyperlight-dev/hyperlight#2025), so the nightly is not red for that known cause. They still run and log; macOS, Windows and every other job stay strict.
+- CI: a wedged HTTP demo fails once its five-minute wait for an answer runs out (60 tries, each a 3 s request and a 2 s pause), instead of holding its job until the timeout (the Linux arm64 nightly's demos job sat at its 90-minute ceiling): the demo harness captures the server's output to a file instead of a pipe it never drained, and stops the server with a bounded terminate, then kill.
 
 ### Fixed
 
+- Under a restricted network policy (`AllowList`, `BlockList` or `Filter`), a name lookup with `AI_ADDRCONFIG`, as Node makes for a connection to a hostname, failed with `getaddrinfo EACCES` (#247): musl probes the address families it can use with a UDP `connect()`, to loopback among others, which the policy refused. A UDP `connect()` sends nothing, so it is no longer checked, and keeps the host's own errors; each send on a connected UDP socket is checked instead, against its peer, after a reconnect or an `AF_UNSPEC` disconnect too, as an unconnected `sendto()` already was. TCP is checked at its connect, as before.
 - The kernel allocated scratch pages the host reserves at the top of scratch. It now stops below them.
 - A guest that ran out of scratch during a copy-on-write fault crashed the VM (an unexpected exit) instead of aborting.
 - On x86, a page fault the kernel could not handle early in boot or in its fault handler ended the guest as if it had finished: a guest function call that hit one looked complete. The guest aborts.

diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "hyperlight-unikraft"
-version = "0.20.1"
+version = "0.21.0"
 edition = "2024"
 description = "Run ordinary Linux programs inside Hyperlight micro-VMs using a Unikraft unikernel as the guest kernel — the hluk CLI and library."
 license = "Apache-2.0"
@@ -38,7 +38,7 @@ mshv = ["hyperlight-host/mshv3"]
 cpio = ["dep:tar"]
 
 [dependencies]
-hyperlight-common = "0.18"
+hyperlight-common = "0.19"
 serde_json = "1"
 thiserror = "2"
 tracing = "0.1"
@@ -85,12 +85,12 @@ sha2 = { version = "0.11", optional = true }
 #   Windows — WHP, compiled in unconditionally for the target (no feature).
 #   macOS   — Hypervisor.framework via the default `hvf` feature.
 [target.'cfg(target_os = "linux")'.dependencies]
-hyperlight-host = { version = "0.18", default-features = false, features = ["kvm", "build-metadata"] }
+hyperlight-host = { version = "0.19", default-features = false, features = ["kvm", "build-metadata"] }
 
 # Non-Linux keeps hyperlight's defaults: HVF (macOS) is on, WHP (Windows) is
 # unconditional, and the Linux-only kvm/mshv3 features are inert here.
 [target.'cfg(not(target_os = "linux"))'.dependencies]
-hyperlight-host = "0.18"
+hyperlight-host = "0.19"
 
 [target.'cfg(windows)'.dependencies]
 # Private working set for the bench RSS line (already in the tree via clap).
@@ -103,10 +103,3 @@ tracing-subscriber = { version = "0.3", default-features = false, features = ["r
 # The FlatBuffer decoder's external-value source, mirrored in the tests.
 anyhow = "1"
 bytes = "1"
-
-# hyperlight main, for scratch resize (#1947) and scratch_allocated_bytes
-# (#2019). crates.io takes no git dependency, so hyperlight-unikraft is not
-# published until a hyperlight release replaces this.
-[patch.crates-io]
-hyperlight-host = { git = "https://github.com/hyperlight-dev/hyperlight", rev = "6c17f7cd4e78b03d77fadf4cfe749d7ede96b7ab" }
-hyperlight-common = { git = "https://github.com/hyperlight-dev/hyperlight", rev = "6c17f7cd4e78b03d77fadf4cfe749d7ede96b7ab" }
diff --git a/build.rs b/build.rs
@@ -11,7 +11,7 @@ use std::path::{Path, PathBuf};
 use sha2::{Digest, Sha256};
 
 /// The host side of the guest contract: the host functions and their
-/// meaning, the virtqueue pool sizes, the heap, scratch and initrd layout,
+/// meaning, the virtqueue pool sizes, the scratch and initrd layout,
 /// the guest MSR list, and the hyperlight-host release that reads a
 /// snapshot.  Bump it when any of those changes in a way a snapshot would
 /// notice; a kernel change rolls the key by itself.

diff --git a/defconfig-elfloader b/defconfig-elfloader
@@ -1,8 +1,7 @@
 CONFIG_UK_NAME="elfloader"
 CONFIG_PLAT_HYPERLIGHT=y
-# Paging + vmem (must be explicit — elfloader's imply doesn't stick)
-CONFIG_LIBUKPAGING=y
-CONFIG_LIBUKFALLOC=y
+# PLAT_HYPERLIGHT selects paging.
+# vmem must be explicit (elfloader's imply doesn't stick).
 CONFIG_LIBUKVMEM=y
 CONFIG_LIBUKVMEM_DEFAULT_BASE=0x0000001000000000
 CONFIG_LIBUKVMEM_DEMAND_PAGE_IN_SIZE=12

diff --git a/demos/pptx-gen/Cargo.lock b/demos/pptx-gen/Cargo.lock
diff --git a/demos/pptx-gen/Cargo.toml b/demos/pptx-gen/Cargo.toml
@@ -15,10 +15,3 @@ dotenvy = "0.15"
 anyhow = "1"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
-
-# hyperlight main, for scratch resize (#1947) and scratch_allocated_bytes
-# (#2019). crates.io takes no git dependency, so hyperlight-unikraft is not
-# published until a hyperlight release replaces this.
-[patch.crates-io]
-hyperlight-host = { git = "https://github.com/hyperlight-dev/hyperlight", rev = "6c17f7cd4e78b03d77fadf4cfe749d7ede96b7ab" }
-hyperlight-common = { git = "https://github.com/hyperlight-dev/hyperlight", rev = "6c17f7cd4e78b03d77fadf4cfe749d7ede96b7ab" }