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Subject: Re: [PATCH 40/70] x86/sev-es: Setup per-cpu GHCBs for the runtime
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From:   Tom Lendacky <thomas.lendacky@amd.com>
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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