On Tue, 2023-05-09 at 12:37 -0400, Neal Gompa wrote: > On Tue, May 9, 2023 at 12:31 PM Lennart Poettering <mzerqung@xxxxxxxxxxx> wrote: > > > > On Di, 09.05.23 08:22, Neal Gompa (ngompa13@xxxxxxxxx) wrote: > > > > > I've been asked to consider converting /boot to a Btrfs subvolume so > > > that it no longer has a fixed space allocation to deal with the ever > > > increasing amount of firmware required for NVIDIA GPUs[1]. This is > > > currently incompatible with how systemd views the world, because the > > > "discoverable partition spec" is wired to partitions, and there is no > > > equivalent spec for subvolumes of a volume. And I imagine that > > > XBOOTLDR (whatever that is) also would have a problem with this. > > > > This makese no sense. If you want /boot to just be a subvolume of the > > rootfs btrfs, then this would imply it's also covered by the same > > security choices, i.e. encryption. We want to bind that sooner or > > later to things like TPM2, FIDO2, PKCS11. And that's simply not > > feasible from a boot loader environment. > > > > Hence, the place the kernel is loaded from (regardless if you call it > > /efi or /boot or /boot/efi, and regardless what fs it is) must be > > accessible from the boot loader easily, without requiring > > implementation of TPM2/FIDO2/PKCS11 hookup in the boot loader. > > > > Hence: btrfs subvols won't work for this > > If we're not using LUKS for encryption, then this is not a problem. > We're generally looking toward encrypting subvolumes individually > using the upcoming Btrfs native encryption capability rather than > using LUKS. That allows us to > > 1. Pick which subvolumes are encrypted > 2. Pick the security binding method per subvolume > > For example, the root and home subvolumes would use TPM or some other > non-interactive binding. The user subvolume in home would decrypt with > user login. Neal, I think you are barking up the wrong tree here. The design of the boot loader *nedds* to be simple. Simple means, VFAT and *no trust* in the filesystem, individual files are signed and verified. Only the bare minimum *necessary* is in the boot partition, which means kernel images and the bare minimum init image needed to unlock and mount the root partition. There is no point in building a more complex system than that and load tons of garbage drivers in the EFI. Booting is a staged system, and should be kept as simple as possible to avoid duplication (which means subtle bugs and a ton of maintenance overhead). Simo. -- Simo Sorce RHEL Crypto Team Red Hat, Inc _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
