Re: [PATCH] x86/unaccepted_memory: Do not accept ranges that are no longer E820 RAM

[Ard Biesheuvel]

On Mon, 2 Nov 2026, at 13:01, Gupta, Pankaj wrote:
>>>>
>>> Can we just disallow memmap= when running in a confidential VM?
>>
>> My experiments showed: memmap itself don't have a problem but memap 
>> with a hole is causing crash.
>>
>> There might be some usecases which are already using this, e.g:
>>
>> https://lore.kernel.org/all/20261029-cma-multi-v1-0-2cbced8b5cb7@xxxxxxxxxx/ 
>>
>>
> Its also good to have a general safeguard to not accept memory that is 
> not marked as RAM in e820?
>

Personally, I think all these command line hacks should be avoided in
confidential VMs, on the basis that the firmware's view of memory should
be in sync with the OS.