* update spectre v2 microcodes blacklist
@ 2018-02-10 12:31 Alexander Sergeyev
2018-02-10 17:14 ` Alexander Sergeyev
0 siblings, 1 reply; 5+ messages in thread
From: Alexander Sergeyev @ 2018-02-10 12:31 UTC (permalink / raw)
To: David Woodhouse
Cc: Thomas Gleixner, Ingo Molnar, H. Peter Anvin, x86, Kyle Huey,
Greg Kroah-Hartman, Levin, Alexander (Sasha Levin),
Peter Zijlstra, linux-kernel
Hello,
Intel released an updated microcode revision guidance [1] (8 Feb). The link is
available in press-release [2], but it's quite easy to miss.
Some microcode revisions that were blacklisted before are now tested and
pronounced production-ready:
> Lines with “***” were previously recommended to discontinue use.
> Subsequent testing by Intel has determined that these were unaffected
> by the stability issues and have been re-released without
> modification.
I didn't fully match the updated revision guidance and spectre_bad_microcodes[]
in arch/x86/kernel/cpu/intel.c, but at least microcode 0xc2 for intel skylakes
should not be blacklisted anymore.
The update is also revelant to a recent blacklist backport to 4.9-stable:
https://patchwork.kernel.org/patch/10209021/
[1] https://newsroom.intel.com/wp-content/uploads/sites/11/2018/02/microcode-update-guidance.pdf
[2] https://newsroom.intel.com/news/security-issue-update-progress-continues-firmware-updates/
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: update spectre v2 microcodes blacklist 2018-02-10 12:31 update spectre v2 microcodes blacklist Alexander Sergeyev @ 2018-02-10 17:14 ` Alexander Sergeyev 2018-02-12 9:34 ` David Woodhouse 0 siblings, 1 reply; 5+ messages in thread From: Alexander Sergeyev @ 2018-02-10 17:14 UTC (permalink / raw) To: David Woodhouse Cc: Thomas Gleixner, Ingo Molnar, H. Peter Anvin, x86, Kyle Huey, Greg Kroah-Hartman, Levin, Alexander (Sasha Levin), Peter Zijlstra, linux-kernel [-- Attachment #1: Type: text/plain, Size: 1933 bytes --] >I didn't fully match the updated revision guidance and spectre_bad_microcodes I compared these lists and it seems that the only difference is about skylakes. Everything else is covered by less-or-equal criteria on revision version. Both desktop and mobile skylakes are stated to be unaffected for 0xC2: { INTEL_FAM6_SKYLAKE_DESKTOP, 0x03, 0xc2 }, // signature 0x000506E3 { INTEL_FAM6_SKYLAKE_MOBILE, 0x03, 0xc2 }, // signature 0x000406E3 I reformated the Intel bulletin into json format for ease of automation and batch processing -- it is attached. Raw diff between the mainline blacklist and the bulletin looks like: @@ -1,5 +1,6 @@ { INTEL_FAM6_BROADWELL_CORE, 0x04, 0x28 }, { INTEL_FAM6_BROADWELL_GT3E, 0x01, 0x1b }, +{ INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000023 }, { INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000025 }, { INTEL_FAM6_BROADWELL_XEON_D, 0x02, 0x14 }, { INTEL_FAM6_BROADWELL_XEON_D, 0x03, 0x07000011 }, @@ -9,12 +10,10 @@ { INTEL_FAM6_HASWELL_X, 0x02, 0x3b }, { INTEL_FAM6_HASWELL_X, 0x04, 0x10 }, { INTEL_FAM6_IVYBRIDGE_X, 0x04, 0x42a }, -{ INTEL_FAM6_KABYLAKE_DESKTOP, 0x09, 0x84 }, -{ INTEL_FAM6_KABYLAKE_DESKTOP, 0x0a, 0x84 }, -{ INTEL_FAM6_KABYLAKE_DESKTOP, 0x0b, 0x84 }, -{ INTEL_FAM6_KABYLAKE_MOBILE, 0x09, 0x84 }, -{ INTEL_FAM6_KABYLAKE_MOBILE, 0x0a, 0x84 }, -{ INTEL_FAM6_SKYLAKE_DESKTOP, 0x03, 0xc2 }, -{ INTEL_FAM6_SKYLAKE_MOBILE, 0x03, 0xc2 }, -{ INTEL_FAM6_SKYLAKE_X, 0x03, 0x0100013e }, +{ INTEL_FAM6_KABYLAKE_DESKTOP, 0x09, 0x80 }, +{ INTEL_FAM6_KABYLAKE_DESKTOP, 0x0a, 0x80 }, +{ INTEL_FAM6_KABYLAKE_DESKTOP, 0x0b, 0x80 }, +{ INTEL_FAM6_KABYLAKE_MOBILE, 0x09, 0x80 }, +{ INTEL_FAM6_KABYLAKE_MOBILE, 0x0a, 0x80 }, +{ INTEL_FAM6_SKYLAKE_X, 0x04, 0x0200003a }, { INTEL_FAM6_SKYLAKE_X, 0x04, 0x0200003c }, Note: Gemini Lake and Sandy Bridge are not considered (observed in wild). [-- Attachment #2: microcode-update-guidance.json --] [-- Type: application/json, Size: 34851 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: update spectre v2 microcodes blacklist 2018-02-10 17:14 ` Alexander Sergeyev @ 2018-02-12 9:34 ` David Woodhouse 2018-02-12 13:56 ` Van De Ven, Arjan 0 siblings, 1 reply; 5+ messages in thread From: David Woodhouse @ 2018-02-12 9:34 UTC (permalink / raw) To: Alexander Sergeyev, Van De Ven, Arjan Cc: Thomas Gleixner, Ingo Molnar, H. Peter Anvin, x86, Kyle Huey, Greg Kroah-Hartman, Levin, Alexander (Sasha Levin), Peter Zijlstra, linux-kernel [-- Attachment #1: Type: text/plain, Size: 2787 bytes --] On Sat, 2018-02-10 at 20:14 +0300, Alexander Sergeyev wrote: > > > > I didn't fully match the updated revision guidance and spectre_bad_microcodes > I compared these lists and it seems that the only difference is about skylakes. > Everything else is covered by less-or-equal criteria on revision version. > > Both desktop and mobile skylakes are stated to be unaffected for 0xC2: > > { INTEL_FAM6_SKYLAKE_DESKTOP, 0x03, 0xc2 }, // signature 0x000506E3 > { INTEL_FAM6_SKYLAKE_MOBILE, 0x03, 0xc2 }, // signature 0x000406E3 > > I reformated the Intel bulletin into json format for ease of automation and > batch processing -- it is attached. > > Raw diff between the mainline blacklist and the bulletin looks like: > @@ -1,5 +1,6 @@ > { INTEL_FAM6_BROADWELL_CORE, 0x04, 0x28 }, > { INTEL_FAM6_BROADWELL_GT3E, 0x01, 0x1b }, > +{ INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000023 }, > { INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000025 }, That's redundant since blacklisting 0x0b000025 will also stop us from using 0x0b000023 anyway. > -{ INTEL_FAM6_KABYLAKE_DESKTOP, 0x09, 0x84 }, > -{ INTEL_FAM6_KABYLAKE_DESKTOP, 0x0a, 0x84 }, > -{ INTEL_FAM6_KABYLAKE_DESKTOP, 0x0b, 0x84 }, > -{ INTEL_FAM6_KABYLAKE_MOBILE, 0x09, 0x84 }, > -{ INTEL_FAM6_KABYLAKE_MOBILE, 0x0a, 0x84 }, No, let's not assume 0x84 will be safe on those just yet. Intel mentioned 0x84 as bad in one of the revisions of the doc, and it's safer to leave it blacklisted until they explicitly say otherwise. > -{ INTEL_FAM6_SKYLAKE_DESKTOP, 0x03, 0xc2 }, > -{ INTEL_FAM6_SKYLAKE_MOBILE, 0x03, 0xc2 }, OK. With 0xc2 being exonerated, I believe there is *no* publicly released microcode for these which needs to be blacklisted, so they can be removed entirely. > -{ INTEL_FAM6_SKYLAKE_X, 0x03, 0x0100013e }, Again, that appeared in an earlier version of the document and hasn't been explicitly cleared. > +{ INTEL_FAM6_SKYLAKE_X, 0x04, 0x0200003a }, > { INTEL_FAM6_SKYLAKE_X, 0x04, 0x0200003c }, Redundant again. > Note: Gemini Lake and Sandy Bridge are not considered (observed in wild). Ah, but we have more information now from the doc. The Gemini Lake 0x22 was observed in the wild, sure, but is also explicitly mentioned as OK in the latest doc. So I removed it from the blacklist (again, with no prior Gemini Lake bad microcode, so the line can be removed entirely). The Sandy Bridge ones observed in the wild are, however, *newer* than the "Pre-Mitigation Production MCU" listed for the corresponding CPU in the table, and thus we should assume they should still be blacklisted. [-- Attachment #2: smime.p7s --] [-- Type: application/x-pkcs7-signature, Size: 5213 bytes --] ^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: update spectre v2 microcodes blacklist 2018-02-12 9:34 ` David Woodhouse @ 2018-02-12 13:56 ` Van De Ven, Arjan 2018-02-12 14:11 ` Alexander Sergeyev 0 siblings, 1 reply; 5+ messages in thread From: Van De Ven, Arjan @ 2018-02-12 13:56 UTC (permalink / raw) To: David Woodhouse, Alexander Sergeyev Cc: Thomas Gleixner, Ingo Molnar, H. Peter Anvin, x86, Kyle Huey, Greg Kroah-Hartman, Levin, Alexander (Sasha Levin), Peter Zijlstra, linux-kernel > > Raw diff between the mainline blacklist and the bulletin looks like: > > @@ -1,5 +1,6 @@ > > { INTEL_FAM6_BROADWELL_CORE, 0x04, 0x28 }, > > { INTEL_FAM6_BROADWELL_GT3E, 0x01, 0x1b }, > > +{ INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000023 }, > > { INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000025 }, > > That's redundant since blacklisting 0x0b000025 will also stop us from > using 0x0b000023 anyway. and 23 is the pre security version so known good. ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: update spectre v2 microcodes blacklist 2018-02-12 13:56 ` Van De Ven, Arjan @ 2018-02-12 14:11 ` Alexander Sergeyev 0 siblings, 0 replies; 5+ messages in thread From: Alexander Sergeyev @ 2018-02-12 14:11 UTC (permalink / raw) To: Van De Ven, Arjan Cc: David Woodhouse, Thomas Gleixner, Ingo Molnar, H. Peter Anvin, x86, Kyle Huey, Greg Kroah-Hartman, Levin, Alexander (Sasha Levin), Peter Zijlstra, linux-kernel >>> +{ INTEL_FAM6_BROADWELL_X, 0x01, 0x0b000023 }, >> That's redundant since blacklisting 0x0b000025 will also stop us from >> using 0x0b000023 anyway. >and 23 is the pre security version so known good. But 0x0b000023 is listed under "stop deploying these MCU revs" (page 4, row 4). Has something changed? ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2018-02-12 14:11 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2018-02-10 12:31 update spectre v2 microcodes blacklist Alexander Sergeyev 2018-02-10 17:14 ` Alexander Sergeyev 2018-02-12 9:34 ` David Woodhouse 2018-02-12 13:56 ` Van De Ven, Arjan 2018-02-12 14:11 ` Alexander Sergeyev
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