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

From	Borislav Petkov <bp@alien8.de>
Newsgroups	linux.kernel
Subject	Re: [PATCH v6 23/34] x86, realmode: Decrypt trampoline area if memory encryption is active
Date	2017-06-14 18:30 +0200
Message-ID	<tSjl8-7u8-15@gated-at.bofh.it> (permalink)
References	<tPRjk-44i-19@gated-at.bofh.it> <tSjl8-7u8-17@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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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.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

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Re: [PATCH v6 23/34] x86, realmode: Decrypt trampoline area if  memory encryption is active Borislav Petkov <bp@alien8.de> - 2017-06-14 18:30 +0200

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