Reuse NixOS initrd

[astro]

No longer requires a custom kernel build

• Update build-vm.nix
• Extend the checks
• Wait for NixOS 23.05

Call for users who run on nixos-unstable: please test and leave emojis here!

[mikatammi]

This looks like an interesting work, I'll need to find time to test this out.

I have only one wish, could we retain the functionality that we can build our custom kernel, eg. behind an option? We actually have usecases where we would like to run different custom kernels, meaning different versions, with different kernel configurations and patches in different microvms

I've been already doing some work to enable custom kernels in microvms, but have not yet done any PR

[astro]

I have only one wish, could we retain the functionality that we can build our custom kernel, eg. behind an option? We actually have usecases where we would like to run different custom kernels, meaning different versions, with different kernel configurations and patches in different microvms

With this you will be able to use normal NixOS configuration mechanisms, no more extra hoops to jump through.

I've been already doing some work to enable custom kernels in microvms, but have not yet done any PR

You should stop doing any kernel configuration that is specific to microvm.nix. Please test this. I want to merge it once the nixos-23.05 branch is born.

[Dan-Theriault]

I get a build failure trying to run this:

error: builder for '/nix/store/vj3i1c8n0h3w8psgkyf0az70sz1mx741-bash-5.2-p15-x86_64-elf.drv' failed with exit code 77;
       last 10 log lines:
       > checking build system type... x86_64-unknown-linux-gnu
       > checking host system type... x86_64-pc-elf
       >
       > Beginning configuration for bash-5.2-release for x86_64-pc-elf
       >
       > checking for x86_64-elf-gcc... x86_64-elf-gcc
       > checking whether the C compiler works... no
       > configure: error: in `/build/bash-5.2':
       > configure: error: C compiler cannot create executables
       > See `config.log' for more details
       For full logs, run 'nix log /nix/store/vj3i1c8n0h3w8psgkyf0az70sz1mx741-bash-5.2-p15-x86_64-elf.drv'.
error: 1 dependencies of derivation '/nix/store/iqp3glibnf2vfzh29k9d96rmlh4ac8xc-cargo.drv' failed to build
error: 1 dependencies of derivation '/nix/store/xa6d9la5iavcn4c75z3vsfzf5iyms6wj-rust-hypervisor-firmware-x86_64-elf-0.4.2.drv' failed to build
error: 1 dependencies of derivation '/nix/store/9v8dk14gamma7y5qffa6fv039f895gl6-microvm-run.drv' failed to build
error: 1 dependencies of derivation '/nix/store/kd1kq88ixllsi3p97wxkgjl9xnvpalrq-microvm-run.drv' failed to build
error: 1 dependencies of derivation '/nix/store/mr2vgnadg27g4j52njhx6vvw6ib8ax2d-microvm-run.drv' failed to build
error: 1 dependencies of derivation '/nix/store/yjy0kcrgpnlbck3l5x7nw08cxkivrivk-microvm-cloud-hypervisor-burnham.drv' failed to build
error: 1 dependencies of derivation '/nix/store/8d2cqi3qiqwv6k6i6ghakqs4drgj7pxs-microvm-cloud-hypervisor-marden.drv' failed to build
error: 1 dependencies of derivation '/nix/store/p7wsggnj8xdxyjjd9yr1458ibh6lh2ff-microvm-cloud-hypervisor-suncook.drv' failed to build
error: 1 dependencies of derivation '/nix/store/vx8mbzig1nwx5prhv5416cdxd5wgjxjp-unit-script-install-microvm-burnham-start.drv' failed to build
error: 1 dependencies of derivation '/nix/store/yk7yvq4639y8mg7jxhk7rfqifbs2gv89-unit-script-install-microvm-marden-start.drv' failed to build
error: 1 dependencies of derivation '/nix/store/5gw0qkn8zdnmf2fv2gl58i250bn3hciw-unit-script-install-microvm-suncook-start.drv' failed to build
error: 1 dependencies of derivation '/nix/store/70mls02dvvh9iayn27z2m3xqj9f1zl35-unit-install-microvm-burnham.service.drv' failed to build
error: 1 dependencies of derivation '/nix/store/cys0h4np6ma7jp7ym3l1f5nxrj8m3b2l-system-units.drv' failed to build
error (ignored): error: interrupted by the user
error: 1 dependencies of derivation '/nix/store/rbvmdsaq1fv5iacllizalsss4gdndfzn-etc.drv' failed to build
error: 1 dependencies of derivation '/nix/store/wxc9b1ywx11k2da8nich4qffcbdd2kaa-nixos-system-merrimack-23.05.20230419.645bc49.drv' failed to buil

[astro]

Yes, rust-hypervisor-firmware (required for cloud-hypervisor) has been broken in upstream nixpkgs but I have problems finding the breaking change using git bisect. and the drama unfolds here: NixOS/nixpkgs#228106

[hissssst]

Worked correctly with my simple qemu declarative setup. Great job ❤️

[astro]

With nixos-23.05 having branched off, rust-hypervisor-firmware is now available to Flake users who want to stay on a stable branch. I hope this work makes life easier for everyone.