linux-kernel - Re: [PATCH v3 0/5] x86: SME: BSP/SME microcode update fix

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Date:   Wed, 10 Jan 2018 15:26:03 -0600
From:   Tom Lendacky <thomas.lendacky@....com>
To:     Gabriel C <nix.or.die@...il.com>, x86@...nel.org
Cc:     Brijesh Singh <brijesh.singh@....com>,
        linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...hat.com>,
        Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH v3 0/5] x86: SME: BSP/SME microcode update fix

On 1/10/2018 3:14 PM, Gabriel C wrote:
> On 10.01.2018 20:25, Tom Lendacky wrote:
> 
> Hi Tom ,
> 
>> This patch series addresses an issue when SME is active and the BSP
>> is attempting to check for and load microcode during load_ucode_bsp().
>> Since the initrd has not been decrypted (yet) and the virtual address
>> of the initrd treats the memory as encrypted, the CPIO archive parsing
>> fails to locate the microcode.
>>
>> This series moves the encryption of the initrd into the early boot code
>> and encrypts it at the same time that the kernel is encrypted.  Since
>> the initrd is now encrypted, the CPIO archive parsing succeeds in
>> properly locating the microcode.
>>
>> The following patches are included in this fix:
>> - Cleanup register saving in arch/x86/mm/mem_encrypt_boot.S
>> - Reduce parameters and complexity for creating the SME PGD mappings
>> - Centralize the use of the PMD flags used in sme_encrypt_kernel() in
>>    preparation for using PTE flags also.
>> - Prepare sme_encrypt_kernel() to handle PAGE aligned encryption, not
>>    just 2MB large page aligned encryption.
>> - Encrypt the initrd in sme_encrypt_kernel() when the kernel is being
>>    encrypted.
>>
>> This patch series is based on tip/master.
> 
> Is something in tip/master the patch serie need ?

That's just how I have to submit the patches.  You could try applying them
onto whatever tree you like, I don't imagine any conflicts would be too
difficult to resolve if you encounter any.

Thanks,
Tom

> 
> I would like to test the serie however tip/master
> breaks my box.. On tip/master there is no way to boot
> with mem_crypt=on with or without your patches.
> 
> With mem_crypt=off the box at least boots to a point , seems APCI breaks
> on tip/master.
> 
> If someone want to take a look , a dmesg of the broken boot can be found
> there:
> 
> http://sigsegv.24-7.ro/~crazy/tip-master/dmesg-tip-master.txt
> 
> Regards,
> 
> Gabriel C
> 
>