Hello,

nice to see integration of Spectre-Meltdown info in 4.1.9, both for guests and hosts, as detailed in release notes:

I have upgraded my CentOS 7.4 engine VM (outside of oVirt cluster) and one oVirt host to 4.1.9.

Now in General -> Software subtab of the host I see:

OS Version: RHEL - 7 - 4.1708.el7.centos

OS Description: CentOS Linux 7 (Core)

Kernel Version: 3.10.0 - 693.17.1.el7.x86_64

Kernel Features: IBRS: 0, PTI: 1, IBPB: 0

Am I supposed to manually set any particular value?

If I run version 0.32 (updated yesterday) of spectre-meltdown-checker.sh I got this on my Dell M610 blade with 

        Version: 6.4.0

        Release Date: 07/18/2013

[root@ov200 ~]# /home/g.cecchi/spectre-meltdown-checker.sh 

Spectre and Meltdown mitigation detection tool v0.32

Checking for vulnerabilities on current system

Kernel is Linux 3.10.0-693.17.1.el7.x86_64 #1 SMP Thu Jan 25 20:13:58 UTC 2018 x86_64

CPU is Intel(R) Xeon(R) CPU           X5690  @ 3.47GHz

Hardware check

* Hardware support (CPU microcode) for mitigation techniques

  * Indirect Branch Restricted Speculation (IBRS)

    * SPEC_CTRL MSR is available:  NO 

    * CPU indicates IBRS capability:  NO 

  * Indirect Branch Prediction Barrier (IBPB)

    * PRED_CMD MSR is available:  NO 

    * CPU indicates IBPB capability:  NO 

  * Single Thread Indirect Branch Predictors (STIBP)

    * SPEC_CTRL MSR is available:  NO 

    * CPU indicates STIBP capability:  NO 

  * Enhanced IBRS (IBRS_ALL)

    * CPU indicates ARCH_CAPABILITIES MSR availability:  NO 

    * ARCH_CAPABILITIES MSR advertises IBRS_ALL capability:  NO 

  * CPU explicitly indicates not being vulnerable to Meltdown (RDCL_NO):  NO 

* CPU vulnerability to the three speculative execution attacks variants

  * Vulnerable to Variant 1:  YES 

  * Vulnerable to Variant 2:  YES 

  * Vulnerable to Variant 3:  YES 

CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'

* Checking count of LFENCE opcodes in kernel:  YES 

> STATUS:  NOT VULNERABLE  (107 opcodes found, which is >= 70, heuristic to be improved when official patches become available)

CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'

* Mitigation 1

  * Kernel is compiled with IBRS/IBPB support:  YES 

  * Currently enabled features

    * IBRS enabled for Kernel space:  NO  (echo 1 > /sys/kernel/debug/x86/ibrs_enabled)

    * IBRS enabled for User space:  NO  (echo 2 > /sys/kernel/debug/x86/ibrs_enabled)

    * IBPB enabled:  NO  (echo 1 > /sys/kernel/debug/x86/ibpb_enabled)

* Mitigation 2

  * Kernel compiled with retpoline option:  NO 

  * Kernel compiled with a retpoline-aware compiler:  NO 

  * Retpoline enabled:  NO 

> STATUS:  VULNERABLE  (IBRS hardware + kernel support OR kernel with retpoline are needed to mitigate the vulnerability)

CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'

* Kernel supports Page Table Isolation (PTI):  YES 

* PTI enabled and active:  YES 

* Running as a Xen PV DomU:  NO 

> STATUS:  NOT VULNERABLE  (PTI mitigates the vulnerability)

A false sense of security is worse than no security at all, see --disclaimer

[root@ov200 ~]# 

So it seems I'm still vulnerable only to Variant 2, but kernel seems ok:

  * Kernel is compiled with IBRS/IBPB support:  YES 

while bios not, correct?

Is RH EL / CentOS expected to follow the retpoline option too, to mitigate Variant 2, as done by Fedora for example?

Eg on my just updated Fedora 27 laptop I get now:

[g.cecchi@ope46 spectre_meltdown]$ sudo ./spectre-meltdown-checker.sh

[sudo] password for g.cecchi: 

Spectre and Meltdown mitigation detection tool v0.32

Checking for vulnerabilities on current system

Kernel is Linux 4.14.14-300.fc27.x86_64 #1 SMP Fri Jan 19 13:19:54 UTC 2018 x86_64

CPU is Intel(R) Core(TM) i7-2620M CPU @ 2.70GHz

Hardware check

* Hardware support (CPU microcode) for mitigation techniques

  * Indirect Branch Restricted Speculation (IBRS)

    * SPEC_CTRL MSR is available:  NO 

    * CPU indicates IBRS capability:  NO 

  * Indirect Branch Prediction Barrier (IBPB)

    * PRED_CMD MSR is available:  NO 

    * CPU indicates IBPB capability:  NO 

  * Single Thread Indirect Branch Predictors (STIBP)

    * SPEC_CTRL MSR is available:  NO 

    * CPU indicates STIBP capability:  NO 

  * Enhanced IBRS (IBRS_ALL)

    * CPU indicates ARCH_CAPABILITIES MSR availability:  NO 

    * ARCH_CAPABILITIES MSR advertises IBRS_ALL capability:  NO 

  * CPU explicitly indicates not being vulnerable to Meltdown (RDCL_NO):  NO 

* CPU vulnerability to the three speculative execution attacks variants

  * Vulnerable to Variant 1:  YES 

  * Vulnerable to Variant 2:  YES 

  * Vulnerable to Variant 3:  YES 

CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'

* Mitigated according to the /sys interface:  NO  (kernel confirms your system is vulnerable)

> STATUS:  VULNERABLE  (Vulnerable)

CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'

* Mitigated according to the /sys interface:  YES  (kernel confirms that the mitigation is active)

* Mitigation 1

  * Kernel is compiled with IBRS/IBPB support:  NO 

  * Currently enabled features

    * IBRS enabled for Kernel space:  NO 

    * IBRS enabled for User space:  NO 

    * IBPB enabled:  NO 

* Mitigation 2

  * Kernel compiled with retpoline option:  YES 

  * Kernel compiled with a retpoline-aware compiler:  YES  (kernel reports full retpoline compilation)

  * Retpoline enabled:  YES 

> STATUS:  NOT VULNERABLE  (Mitigation: Full generic retpoline)

CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'

* Mitigated according to the /sys interface:  YES  (kernel confirms that the mitigation is active)

* Kernel supports Page Table Isolation (PTI):  YES 

* PTI enabled and active:  YES 

* Running as a Xen PV DomU:  NO 

> STATUS:  NOT VULNERABLE  (Mitigation: PTI)

A false sense of security is worse than no security at all, see --disclaimer

[g.cecchi@ope46 spectre_meltdown]$

BTW: I updated some days ago this laptop from F26 to F27 and I remember Variant 1 was fixed in F26, while now I see it as vulnerable..... I'm going to check with Fedora mailing list about this...

Another question: what should I see for a VM instead related to meltdown/spectre?

Currently in "Guest CPU Type" in General subtab of the VM I only see "Westmere"..

Should I also see anythin aout IBRS, etc...?

Thanks,

Gianluca 

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