Re: [PATCH 40/70] x86/sev-es: Setup per-cpu GHCBs for the runtime handler

Tom Lendacky
2020-04-14T20:17:31Z

On 4/14/20 3:12 PM, Dave Hansen wrote:
> On 4/14/20 1:04 PM, Tom Lendacky wrote:
>>> set_memory_decrypted needs to check the return value. I see it
>>> consistently return ENOMEM. I've traced that back to split_large_page
>>> in arch/x86/mm/pat/set_memory.c.
>>
>> At that point the guest won't be able to communicate with the
>> hypervisor, too. Maybe we should BUG() here to terminate further
>> processing?
>
> Escalating an -ENOMEM into a crashed kernel seems a bit extreme.
> Granted, the guest may be in an unrecoverable state, but the host
> doesn't need to be too.
>

The host wouldn't be. This only happens in a guest, so it would be just
causing the guest kernel to panic early in the boot.

Thanks,
Tom