Re: [PATCH v5 12/16] PCI: Add pci_iomap_host_shared(), pci_iomap_host_shared_range()

From: Dan Williams
Date: Tue Oct 12 2021 - 18:00:16 EST


On Tue, Oct 12, 2021 at 2:28 PM Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote:
[..]
> >> But how do you debug the kernel then? Making early undebuggable seems
> >> just bad policy to me.
> > I am not proposing making the early undebuggable.
>
>
> That's the implication of moving the policy into initrd.
>
>
> If only initrd can authorize then it won't be possible to authorize
> before initrd, thus the early console won't work.

Again, the proposal is that the allow-list is limited to just enough
devices to startup and debug the initramfs and no more. Everything
else can be dynamic, and this allows for a powerful custom override
interface without needing to debate additional ABI like command line
overrides, and minimizes future changes to this kernel-internal
allow-list.