[PATCH V2 1/2] efi/unaccepted: Do not let /proc/vmcore try to access unaccepted memory

[David Hildenbrand]

On 12.09.23 09:47, Adrian Hunter wrote:
> On 12/09/23 10:19, David Hildenbrand wrote:
>> On 11.09.23 13:21, Adrian Hunter wrote:
>>> Support for unaccepted memory was added recently, refer commit dcdfdd40fa82
>>> ("mm: Add support for unaccepted memory"), whereby a virtual machine may
>>> need to accept memory before it can be used.
>>>
>>> Do not let /proc/vmcore try to access unaccepted memory because it can
>>> cause the guest to fail.
>>
>> Oh, hold on. What are the actual side effects of this?
>>
>> Once we're in the kdump kernel, any guest is already dead. So failing a guest doesn't apply, no?
>>
> Unaccepted Memory is used by virtual machines.  In this case the guest
> has kexec'ed to a dump-capture kernel, so the virtual machine is still
> alive and running the dump-capture kernel.

Ah, I got lost in TDX host semantics. So what you're saying, if we 
(guest) are reading unnaccepted memory we will get zapped. Makes sense.

-- 
Cheers,

David / dhildenb