From db5f9a1ac8a692f7c6bd9e3f1d2dc59e4397bbce Mon Sep 17 00:00:00 2001 From: Else Someone Date: Wed, 28 Jan 2026 07:19:18 +0200 Subject: [PATCH] README: update & shuffle --- README.md | 40 +++++++++++++++++++++++----------------- 1 file changed, 23 insertions(+), 17 deletions(-) diff --git a/README.md b/README.md index 1faffc4..e90f8c6 100644 --- a/README.md +++ b/README.md @@ -1,20 +1,32 @@ μVMs === -Slowly comprehending [spectrum-os](https://spectrum-os.org) and [microvm.nix](https://github.com/microvm-nix/microvm.nix), by reproducing bits and pieces using [NixOS](https://nixos.org), [systemd](https://nixos.org/manual/nixos/stable/options#opt-systemd.services), and [cloud-hypervisor](https://github.com/cloud-hypervisor/cloud-hypervisor). +Slowly comprehending [spectrum-os](https://spectrum-os.org) and [microvm.nix](https://github.com/microvm-nix/microvm.nix), by reproducing bits and pieces using [NixOS](https://nixos.org) and [cloud-hypervisor](https://github.com/cloud-hypervisor/cloud-hypervisor). Prior Art --- +### Projects + +- Obvious: Qubes, Spectrum, Genode, ... +- Google ChromeOS and [AWS Firecracker](https://firecracker-microvm.github.io): + - rust-vmm, [crosvm](https://crosvm.dev/book), and [sommelier](https://chromium.googlesource.com/chromiumos/platform2/+/master/vm_tools/sommelier); +- [Asahi muvm](https://github.com/AsahiLinux/muvm): microvms using [libkrun](https://github.com/containers/libkrun) and virtio-gpu "native context". +- [AppVM](https://github.com/jollheef/appvm): apparently available in Nixpkgs under `nixos/modules/virtualisation/appvm.nix`. Based on (NixOS,) qemu and libvirt. +- [valpackett/munix](https://git.clan.lol/clan/munix) +- ... + ### People -Following the right people is one of the most effective ways to maintain bibliography, a form of "importance sampling". +Following the right people might one of the most effective ways to maintain bibliography, a form of "importance sampling". The following are the people whose work, at the time of writing, I already know to watch out for. Whom am I missing? - [Alyssa Ross](https://github.com/alyssais) - Via [spectrum.org]https://spectrum-os.org/bibliography.html) and [Nixpkgs](https://github.com/NixOS/Nixpkgs). - [Demi Marie](https://demimarie.github.io): - Via [spectrum-devel](https://spectrum-os.org/lists/archives/spectrum-devel/2ff17d00-6603-46ae-9eb0-d4fa179db86c@gmail.com/) and Qubes. +- [valpackett](https://val.packett.cool) +- yureka - [Thomas Leonard](https://roscidus.com/blog/blog/2021/03/07/qubes-lite-with-kvm-and-wayland) - Via [spectrum-discuss](https://spectrum-os.org/lists/archives/spectrum-discuss/CAG4opy8BZn2pXDRBHOjcENFBHJON1LoG7A8GPdP0Wt_3KLaHyw@mail.gmail.com/), [qubes-lite, and `wayland-proxy-virtwl`](https://roscidus.com/blog/blog/2021/03/07/qubes-lite-with-kvm-and-wayland). - [Astro](https://spaceboyz.net/~astro/): @@ -25,16 +37,6 @@ The following are the people whose work, at the time of writing, I already know - Via [Qubes](https://doc.qubes-os.org/en/latest/developer/general/devel-books.html) [OS](https://theinvisiblethings.blogspot.com/2012/09/how-is-qubes-os-different-from.html). - ... -### Projects - -- Obvious: Qubes, Spectrum, Genode, ... -- Google ChromeOS and [AWS Firecracker](https://firecracker-microvm.github.io): - - rust-vmm, [crosvm](https://crosvm.dev/book), and [sommelier](https://chromium.googlesource.com/chromiumos/platform2/+/master/vm_tools/sommelier); -- [Asahi muvm](https://github.com/AsahiLinux/muvm): microvms using [libkrun](https://github.com/containers/libkrun) and virtio-gpu "native context". -- [AppVM](https://github.com/jollheef/appvm): apparently available in Nixpkgs under `nixos/modules/virtualisation/appvm.nix`. Based on (NixOS,) qemu and libvirt. -- ... - - ### Timeline The following are the questions I'd like to eventually answer about how virtualization happened: @@ -76,7 +78,10 @@ The following are some of the current "am I holding this right?" questions: - [ ] Filesystems: Virtio-blk appears to be the way to allocate persistent storage for VMs that require it. - In practice this means allocating a zvol or a contiguous file on the hypervisor, + The alternative is virtiofsd, which is potentially more RAM-hungry, and which significantly + limits bandwidth at least when used with explicitly enabling DAX (`microvm.nix`). + + In practice the virtio-blk way means allocating a zvol or a contiguous file on the hypervisor, to be exposed to the guest as a block device. One suspicion I have is that allocating a CoW filesystem (e.g. xfs, btrfs) on top of another CoW filesystem (e.g. zfs, as in xfs-on-zvol) may have non-trivial implications for fragmentation, depending on parameters like the chunksizes. @@ -88,14 +93,13 @@ The following are some of the current "am I holding this right?" questions: #### `spectrum-os` -...is in active development and not advertised as user-ready yet. -Spectrum OS appears to be a balance-shifting project, building up towards a principled solution, which must require patience... -It does not, for example, reuse NixOS systemd modules, but uses s6 instead. +Yes. Soon. #### `microvm.nix` Is inherently static. -A cynical spin on `microvm.nix` would be, and I mean it with utmost respect, that it's a glorified qemu flags generator, written in Nix. +A cynical spin on `microvm.nix` would be, and I mean it with utmost respect, that it's a glorified qemu flags generator, written in Nix, +and Nix is slow. When using `microvm.nix` you write, for example, each TAP's `hwaddr` by hand, and then rebuild the "runner script". When using the "fully-declarative mode" you also engangle the guest's and the hypervisor's life cycles, and double the NixOS evaluation time. Microvm-nix ships support for a wide selection of different hypervisors, but you may only care about e.g. `cloud-hypervisor`. @@ -105,3 +109,5 @@ An instructive reference implementation and a convenient entry point, `microvm.n I only noticed the option in `man configuration.nix` a few days ago, so I just never tried. Long-term I'd definitely prefer not to use qemu. + +The golang tool relies on obscure Nix CLI options and "channels" (as in tarballs).