This is a note to let you know that I've just added the patch titled
x86/speculation: Correct Speculation Control microcode blacklist again
to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: x86-speculation-correct-speculation-control-microcode-blacklist-again.patch and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From d37fc6d360a404b208547ba112e7dabb6533c7fc Mon Sep 17 00:00:00 2001
From: David Woodhouse dwmw@amazon.co.uk Date: Mon, 12 Feb 2018 15:27:34 +0000 Subject: x86/speculation: Correct Speculation Control microcode blacklist again
From: David Woodhouse dwmw@amazon.co.uk
commit d37fc6d360a404b208547ba112e7dabb6533c7fc upstream.
Arjan points out that the Intel document only clears the 0xc2 microcode on *some* parts with CPUID 506E3 (INTEL_FAM6_SKYLAKE_DESKTOP stepping 3). For the Skylake H/S platform it's OK but for Skylake E3 which has the same CPUID it isn't (yet) cleared.
So removing it from the blacklist was premature. Put it back for now.
Also, Arjan assures me that the 0x84 microcode for Kaby Lake which was featured in one of the early revisions of the Intel document was never released to the public, and won't be until/unless it is also validated as safe. So those can change to 0x80 which is what all *other* versions of the doc have identified.
Once the retrospective testing of existing public microcodes is done, we should be back into a mode where new microcodes are only released in batches and we shouldn't even need to update the blacklist for those anyway, so this tweaking of the list isn't expected to be a thing which keeps happening.
Requested-by: Arjan van de Ven arjan.van.de.ven@intel.com Signed-off-by: David Woodhouse dwmw@amazon.co.uk Cc: Andy Lutomirski luto@kernel.org Cc: Arjan van de Ven arjan@linux.intel.com Cc: Borislav Petkov bp@alien8.de Cc: Dan Williams dan.j.williams@intel.com Cc: Dave Hansen dave.hansen@linux.intel.com Cc: David Woodhouse dwmw2@infradead.org Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Cc: Josh Poimboeuf jpoimboe@redhat.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Cc: arjan.van.de.ven@intel.com Cc: dave.hansen@intel.com Cc: kvm@vger.kernel.org Cc: pbonzini@redhat.com Link: http://lkml.kernel.org/r/1518449255-2182-1-git-send-email-dwmw@amazon.co.uk Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kernel/cpu/intel.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
--- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -116,13 +116,14 @@ struct sku_microcode { u32 microcode; }; static const struct sku_microcode spectre_bad_microcodes[] = { - { INTEL_FAM6_KABYLAKE_DESKTOP, 0x0B, 0x84 }, - { INTEL_FAM6_KABYLAKE_DESKTOP, 0x0A, 0x84 }, - { INTEL_FAM6_KABYLAKE_DESKTOP, 0x09, 0x84 }, - { INTEL_FAM6_KABYLAKE_MOBILE, 0x0A, 0x84 }, - { INTEL_FAM6_KABYLAKE_MOBILE, 0x09, 0x84 }, + { INTEL_FAM6_KABYLAKE_DESKTOP, 0x0B, 0x80 }, + { INTEL_FAM6_KABYLAKE_DESKTOP, 0x0A, 0x80 }, + { INTEL_FAM6_KABYLAKE_DESKTOP, 0x09, 0x80 }, + { INTEL_FAM6_KABYLAKE_MOBILE, 0x0A, 0x80 }, + { INTEL_FAM6_KABYLAKE_MOBILE, 0x09, 0x80 }, { INTEL_FAM6_SKYLAKE_X, 0x03, 0x0100013e }, { INTEL_FAM6_SKYLAKE_X, 0x04, 0x0200003c }, + { INTEL_FAM6_SKYLAKE_DESKTOP, 0x03, 0xc2 }, { INTEL_FAM6_BROADWELL_CORE, 0x04, 0x28 }, { INTEL_FAM6_BROADWELL_GT3E, 0x01, 0x1b }, { INTEL_FAM6_BROADWELL_XEON_D, 0x02, 0x14 },
Patches currently in stable-queue which might be from dwmw@amazon.co.uk are
queue-4.15/kvm-nvmx-set-the-cpu_based_use_msr_bitmaps-if-we-have-a-valid-l02-msr-bitmap.patch queue-4.15/x86-nvmx-properly-set-spec_ctrl-and-pred_cmd-before-merging-msrs.patch queue-4.15/x86-speculation-update-speculation-control-microcode-blacklist.patch queue-4.15/x86-speculation-correct-speculation-control-microcode-blacklist-again.patch queue-4.15/kvm-x86-reduce-retpoline-performance-impact-in-slot_handle_level_range-by-always-inlining-iterator-helper-methods.patch queue-4.15/x86-speculation-clean-up-various-spectre-related-details.patch queue-4.15/revert-x86-speculation-simplify-indirect_branch_prediction_barrier.patch