[PATCH v6 23/34] x86, realmode: Decrypt trampoline area if memory encryption is active

Tom Lendacky thomas.lendacky at amd.com
Wed Jun 14 09:38:57 PDT 2017


On 6/14/2017 11:24 AM, Borislav Petkov wrote:
> On Wed, Jun 07, 2017 at 02:17:09PM -0500, Tom Lendacky wrote:
>> When Secure Memory Encryption is enabled, the trampoline area must not
>> be encrypted. A CPU running in real mode will not be able to decrypt
>> memory that has been encrypted because it will not be able to use addresses
>> with the memory encryption mask.
>>
>> A recent change that added a new system_state value exposed a warning
>> issued by early_ioreamp() when the system_state was not SYSTEM_BOOTING.
>> At the stage where the trampoline area is decrypted, the system_state is
>> now SYSTEM_SCHEDULING. The check was changed to issue a warning if the
>> system_state is greater than or equal to SYSTEM_RUNNING.
> 
> This piece along with the hunk touching system_state absolutely needs to
> be a separate patch as it is unrelated.

Yup, will do.

Thanks,
Tom

> 



More information about the kexec mailing list