Messages in this thread | | | Date | Wed, 16 Aug 2023 23:58:54 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH 1/2] x86/microcode/AMD: Load late on both threads too |
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On Wed, Aug 16, 2023 at 02:36:57PM -0700, Jim Mattson wrote: > Doesn't this render that attestation misleading, since the microcode > patch may not have been loaded on all logical processors?
For that it doesn't matter because the microcode engine is shared between the two threads. The updated microcode revision is shown on any of the two threads so you can load on one only. And we did this for years.
Only recently we started loading on both and we will be doing that from now on.
What could be problematic is if it simply fails loading on some cores - regardless of SMT - but that would be problematic not only to SEV-SNP attestation but to the general system health. tglx has some patches which verify what has been successfully loaded where so hopefully we'll be verifying more in that area.
HTH.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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