diff --git a/docs/DOCS.md b/docs/DOCS.md
--- a/docs/DOCS.md
+++ b/docs/DOCS.md
@@ -1555,13 +1555,25 @@
   used to sandbox guest networking.
 - `/dev/kvm`: for hardware acceleration (unless you disable
   KVM with `SPINDLE_MICROVM_PIPELINES_ENABLE_KVM=false`).
-- `/dev/vhost-vsock`: the guest agent talks to spindle over
-  vsock.
+- `/dev/vhost-vsock`: used by QEMU to enable guest-to-host vsock
+  communication.
+- `/dev/vsock`: used by spindle on the host to listen on vsock ports
+  and accept guest agent connections.
+- `/dev/net/tun`: required by `slirp4netns` to set up tap devices
+  for sandboxed guest networking.
 
 On NixOS, the [spindle
 module](https://tangled.org/tangled.org/core/blob/master/nix/modules/spindle.nix)
 puts `qemu`, `e2fsprogs`, `slirp4netns`, `iproute2` and
 `util-linux` on the service's `PATH` for you.
+
+#### Container virtualization
+
+Running `spindle` inside a container (e.g., Docker, Podman, or LXD) requires passing host device nodes into the container and granting the runtime additional privileges. Because spindle uses nested namespaces (`unshare`) and helper tools (`slirp4netns`), the container configuration will require:
+
+- `/dev/vsock`, `/dev/vhost-vsock`, `/dev/kvm`, and `/dev/net/tun` mapped from the host.
+- `NET_ADMIN` and `SYS_ADMIN` capabilities to manage network namespaces and mounts inside the container.
+- Relaxed seccomp filters (e.g., `seccomp=unconfined`) and SELinux/AppArmor containment if they restrict namespace creation or device access.
 
 #### Building images
 
diff --git a/spindle/engines/microvm/README.md b/spindle/engines/microvm/README.md
--- a/spindle/engines/microvm/README.md
+++ b/spindle/engines/microvm/README.md
@@ -72,9 +72,10 @@
 and right before launch we also check the referenced files actually exist on
 disk and that the host has the commands we need: `mkfs.ext4` for volume
 formatting, plus whatever the selected runner requires. For QEMU that's the QEMU
-binary for the spec's arch, `/dev/vhost-vsock`, `/dev/kvm` (if KVM is enabled),
-and the `ip`, `mount`, `slirp4netns`, `unshare` toolchain when the image has
-network interfaces.
+binary for the spec's arch, `/dev/vhost-vsock` (for guest vsock configuration),
+`/dev/vsock` (for host listener sockets), `/dev/kvm` (if KVM is enabled), `/dev/net/tun`
+(for guest networking), and the `ip`, `mount`, `slirp4netns`, `unshare` toolchain when the
+image has network interfaces.
 
 ## microVM lifecycle