marvin
90de50dfed
Add support for sharing host directories into the VM via QEMU 9p (virtio-9p). The --mount flag can be repeated; each host directory appears at the same absolute path inside the VM. Design: - QEMU: each --mount gets a short 9p tag (slim0, slim1, …) via -virtfs local,path=…,mount_tag=slimN,security_model=mapped-xattr. Tags are kept short because 9p mount_tag has a ~31-byte limit. - Kernel cmdline: the full destination path is passed as slim.mount=<tag>:<base64(path)> so the init script knows where to mount each tag. Base64 avoids issues with spaces/special chars. - slim-init.sh: after networking, parse slim.mount= entries, mkdir -p the destination, and mount -t 9p <tag> <dest> -o trans=virtio,version=9p2000.L Tests verify: 9p share detection via sysfs mount_tag, 9p entry in mount output, file content accessible at the expected path, and clean VM exit.
slim
Turning containers into bootable VMs
Example
# Build the container
podman build ./example/alpine -t slim-alpine
# Make the container bootable. slim injects /slim/init and /slim/exec,
# then packs the rootfs as a qcow2 disk.
slim build qcow2 slim-alpine
# Boot the image using QEMU. The container's CMD runs automatically.
slim run slim-alpine
# Override the command at runtime (base64-encoded on the kernel cmdline):
slim run slim-alpine --cmd '/bin/sh'
# Override the command at build time (baked into /slim/exec):
slim build qcow2 slim-alpine --cmd '/bin/sh'
# Cleanup
slim image rm slim-alpine
podman image rm slim-alpine
Kernel
slim boots VMs using a shared kernel at $XDG_DATA_HOME/slim-rs/registry/vmlinuz.
Place a suitable x86 bzImage there before running slim run.