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

From: Gabriel C
Date: Wed Jan 10 2018 - 16:15:05 EST


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 ?

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