[elrepo] kernel-lt and microcode updates

Orion Poplawski orion at nwra.com
Wed Jul 1 12:49:55 EDT 2020


On 7/1/20 10:21 AM, elrepo at lists.elrepo.org wrote:
> On 6/30/20 4:11 PM, Phil Perry wrote:
>> On 19/06/2020 16:33, Orion Poplawski wrote:
>>> On 6/18/20 6:45 PM, Akemi Yagi wrote:
>>>> On Thu, Jun 18, 2020 at 9:33 AM Orion Poplawski <orion at nwra.com
>>>> <mailto:orion at nwra.com>> wrote:
>>>>
>>>>      Hello -
>>>>
>>>>      I was poking around and noticed some differences in microcode 
>>>> output in dmesg
>>>>      between the stock EL7 kernel and kernel-lt:
>>>>
>>>>      dmesg-3.10.0-1127.10.1.el7.x86_64:
>>>>      [    0.000000] microcode: microcode updated early to revision 
>>>> 0xd6, date =
>>>>      2019-10-03
>>>>      [    5.997673] microcode: sig=0x406e3, pf=0x80, revision=0xd6
>>>>      [    5.998518] microcode: Microcode Update Driver: v2.01
>>>>      <tigran at aivazian.fsnet.co.uk 
>>>> <mailto:tigran at aivazian.fsnet.co.uk>>, Peter
>>>>      Oruba
>>>>      [    0.000000] microcode: microcode updated early to revision 
>>>> 0xd6, date =
>>>>      2019-10-03
>>>>      [    6.035419] microcode: sig=0x406e3, pf=0x80, revision=0xd6
>>>>      [    6.035503] microcode: Microcode Update Driver: v2.01
>>>>      <tigran at aivazian.fsnet.co.uk 
>>>> <mailto:tigran at aivazian.fsnet.co.uk>>, Peter
>>>>      Oruba
>>>>      [   25.411983] microcode: updated to revision 0xdc, date = 
>>>> 2020-04-27
>>>>
>>>>      dmesg-4.4.227-1.el7.elrepo.x86_64:
>>>>      [    0.052043] SRBDS: Vulnerable: No microcode
>>>>      [    0.052066] MDS: Vulnerable: Clear CPU buffers attempted, no 
>>>> microcode
>>>>      [    1.807176] microcode: CPU0 sig=0x406e3, pf=0x80, revision=0xc6
>>>>      [    1.807189] microcode: CPU1 sig=0x406e3, pf=0x80, revision=0xc6
>>>>      [    1.807210] microcode: CPU2 sig=0x406e3, pf=0x80, revision=0xc6
>>>>      [    1.807230] microcode: CPU3 sig=0x406e3, pf=0x80, revision=0xc6
>>>>      [    1.807312] microcode: Microcode Update Driver: v2.01
>>>>      <tigran at aivazian.fsnet.co.uk 
>>>> <mailto:tigran at aivazian.fsnet.co.uk>>, Peter
>>>>      Oruba
>>>>
>>>>      This leads me to believe that the microcode is not getting 
>>>> updated when using
>>>>      the elrepo lt kernel.  Is that expected?
>>>>
>>>>      Thanks,
>>>>
>>>>         Orion
>>>>
>>>>
>>>> Looks like the explanation is in the posttrans scriptlet of 
>>>> microcode_ctl.
>>>>
>>>> rpm -q --scripts microcode_ctl
>>>>
>>>> [quote]
>>>> ...
>>>> # For RPM selection, kernel flavours (like "debug" or "kdump" or 
>>>> "zfcp",
>>>> # with only the former being relevant to x86 architecture) are a 
>>>> part or RPM
>>>> # name; it's also a part of uname, with different separator used in 
>>>> RHEL 6/7
>>>> # and RHEL 8.  RT kernel, however, is special, as "rt" is another part
>>>> # of RPM name and it has its own versioning scheme both in NVR and 
>>>> uname.
>>>> # And there's the kernel package split in RHEL 8, so one should look 
>>>> for *-core
>>>> # and not the main package.
>>>> pkgs="kernel kernel-debug kernel-rt kernel-rt-debug"
>>>> ...
>>>> [/quote]
>>>>
>>>> Therefore, initramfs will not be regenerated for kernel-ml or 
>>>> kernel-lt.
>>>>
>>>> By the way, the microcode file name as shown by the lsinitrd command 
>>>> is:
>>>>
>>>> kernel/x86/microcode/GenuineIntel.bin (Intel)
>>>>
>>>> or
>>>>
>>>> kernel/x86/microcode/AuthenticAMD.bin (AMD)
>>>>
>>>> Akemi
>>>
>>> While this may be an issue when microcode_ctl updates come in, in 
>>> this case
>>> I've just installed kernel-lt on a system so the initramfs images 
>>> should be fresh.
>>>
>>
>> Agreed. Are you sure that kernel-lt was installed after microcode_ctl? 
>> You can always try reinstalling kernel-lt to test. Kernel-lt doesn't 
>> do anything special, so should incorporate the latest microcode into 
>> it's initramfs image.
>>
>> The %triggerin fix for microcode_ctl updates has been finalised and 
>> tested [1], and we are confident it should fix the issue. It will be 
>> in the next releases of kernel-lt and kernel-ml for el7. We are 
>> currently testing on el8 and expect to roll out there too shortly for 
>> kernel-ml packages.
>>
>> Phil
> 
> I just re-installed kernel-lt on my laptop:
> 
> # grep -i microcode dmesg-3.10.0-1127.13.1.el7.x86_64
> [    0.000000] microcode: microcode updated early to revision 0xd6, date 
> = 2020-04-27
> [    0.021352] SRBDS: Mitigation: Microcode
> [    1.542686] microcode: sig=0x806ea, pf=0x80, revision=0xd6
> [    1.542918] microcode: Microcode Update Driver: v2.01 
> <tigran at aivazian.fsnet.co.uk>, Peter Oruba
> 
> # grep -i microcode dmesg-4.4.228-2.el7.elrepo.x86_64
> [    0.035312] SRBDS: Vulnerable: No microcode
> [    0.992458] microcode: CPU0 sig=0x806ea, pf=0x80, revision=0xb4
> [    0.992471] microcode: CPU1 sig=0x806ea, pf=0x80, revision=0xb4
> [    0.992491] microcode: CPU2 sig=0x806ea, pf=0x80, revision=0xb4
> [    0.992511] microcode: CPU3 sig=0x806ea, pf=0x80, revision=0xb4
> [    0.992530] microcode: CPU4 sig=0x806ea, pf=0x80, revision=0xb4
> [    0.992550] microcode: CPU5 sig=0x806ea, pf=0x80, revision=0xb4
> [    0.992569] microcode: CPU6 sig=0x806ea, pf=0x80, revision=0xb4
> [    0.992588] microcode: CPU7 sig=0x806ea, pf=0x80, revision=0xb4
> [    0.992673] microcode: Microcode Update Driver: v2.01 
> <tigran at aivazian.fsnet.co.uk>, Peter Oruba
> 
> and /proc/cpuinfo indicates that microcode is not updated
> 
> Orion

turning on dracut logging it apprears that:

I:     microcode_ctl: kernel version "4.4.228-2.el7.elrepo.x86_64" 
failed early load check for "intel", skipping

I: *** Generating early-microcode cpio image contents ***
I: *** No early-microcode cpio image needed ***

that check is done in /usr/libexec/microcode_ctl/check_caveats

that is for early loading.  not sure why the microcode.service also 
seems to fail to load the firmware.


-- 
Orion Poplawski
Manager of NWRA Technical Systems          720-772-5637
NWRA, Boulder/CoRA Office             FAX: 303-415-9702
3380 Mitchell Lane                       orion at nwra.com
Boulder, CO 80301                 https://www.nwra.com/

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