diff --git a/docs/landlock.md b/docs/landlock.md index 92ab0648d..8cd873488 100644 --- a/docs/landlock.md +++ b/docs/landlock.md @@ -62,6 +62,31 @@ Landlock can also be enabled during `vm.create` request by passing a config like } ``` +### Multi-file disk formats (VMDK) + +For most block backends (raw, qcow2, VHD) including existing VMDK, landlock +grants access to the `--disk path=` path value. + +For a Flat VMDK, its `path=` points at a small text descriptor whose +data lives in one or more separate extent files. Granting only the descriptor +currently leaves those extents unreachable under landlock. + +The process launching Cloud-Hypervisor must grant these extent paths explicitly +via `--landlock-rules` (or the `landlock_rules` API field). The descriptor file's +extent section mentions the extent file path which can be either: + +- relative (the `qemu-img` default) in which case the full path includes the descriptor +file's parent directory +- absolute, which can live inside the descriptor file's parent directory or in another +directory + +For example, a containerd/Kata deployment where the read-only image +layer resides under `/var/lib/containerd` should add that path: + +``` +--landlock-rules path="/var/lib/containerd",access="rw" +``` + ## Usage Examples