Am 27.03.26 um 2:06 PM schrieb Arthur Bied-Charreton: > On Thu, Mar 26, 2026 at 03:54:53PM +0100, Fiona Ebner wrote: >> Am 12.03.26 um 9:40 AM schrieb Arthur Bied-Charreton: >>> This is picked up from an old series [0] by Stefan Reiter. >>> >>> As of before this series, the only way to create custom CPU models is by >>> editing `/etc/pve/virtual-guest/cpu-models.conf` manually. >>> >>> This can be cumbersome for a few reasons, e.g., due to the fact that flags >>> misconfigurations are only caught when starting the VM. >>> >>> `cpu-flags` endpoint: >>> The `cpu-flags` endpoint previously returned a list of hardcoded flags, >>> which is both non-exhaustive (some flags I should be able to set are >>> missing), >>> and partly incorrect (some flags my host(s) do not support set are >>> returned). >>> This is limiting and can lead to misconfigurations. The updated endpoint >>> intersects all flags QEMU accepts as `-cpu` arguments with all flags the >>> host >>> hardware/emulation actually supports. This way, if I am able to set a flag >>> in >>> the UI, I can be confident that the VM will actually be able to start. >>> >>> Custom CPU model CRUD functionality: >>> Expose CRUD endpoints and UI flow to interact with `cpu-models.conf`. For >>> each >>> flag, show a list of the cluster nodes supporting it, and only expose flags >>> that >>> at least one node supports to avoid misconfigurations. Filter flags by >>> acceleration type (KVM/TCG). >>> >>> [0] >>> https://lore.proxmox.com/pve-devel/[email protected]/ >> >> With a pre-existing, manually added model: >> >> [I] root@pve9a1 ~# cat /etc/pve/virtual-guest/cpu-models.conf >> cpu-model: nested-for-wsl >> flags +svm >> hidden 1 >> hv-vendor-id AuthenticAMD >> reported-model EPYC >> >> When opening it up in the UI, the editor seems to immediately detect a >> change, i.e. the OK button is clickable and when I click it, I get the >> following error: >> >> Parameter verification failed. (400) >> flags: value does not match the regex pattern >> > Thanks a lot for catching that! > >> It seems to be because of the 'svm' flag not being in the flags grid. > Yes, just confirmed that. >> Since users might've already added such models manually, it would be >> nice if it would work. Maybe list the unknown flags in the grid without >> description? > Yes, I will display unknown flags in the grid with empty supported-on > fields. > > On this topic: I currently manually filter out occurrences of svm/vmx to > replace them with nested-virt. Would it make sense to still display them > in the flags selector, even if they overlap with our abstraction?
I think we can still show them and don't need to filter them out. In particular, not having the 'supported-on' for those flags can also lead to confusion, as can (artificially) hiding them from users. I don't see why we should force people to use the abstract 'nested-virt'. It can be convenient for mixed-CPU-vendor clusters, and having the flag be part of the VM-specific ones was the main motivation to add it.
