Comment 11 for bug 1788665

Downloaded and ran the spectre-meltdown-checker.sh

$ spectre-meltdown-checker.sh
Spectre and Meltdown mitigation detection tool v0.39+

Checking for vulnerabilities on current system
Kernel is Linux 4.15.0-33-generic #36-Ubuntu SMP Wed Aug 15 16:00:05 UTC 2018 x86_64
CPU is Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz

Hardware check
* Hardware support (CPU microcode) for mitigation techniques
  * Indirect Branch Restricted Speculation (IBRS)
    * SPEC_CTRL MSR is available: YES
    * CPU indicates IBRS capability: YES (SPEC_CTRL feature bit)
  * Indirect Branch Prediction Barrier (IBPB)
    * PRED_CMD MSR is available: YES
    * CPU indicates IBPB capability: YES (SPEC_CTRL feature bit)
  * Single Thread Indirect Branch Predictors (STIBP)
    * SPEC_CTRL MSR is available: YES
    * CPU indicates STIBP capability: NO
  * Speculative Store Bypass Disable (SSBD)
    * CPU indicates SSBD capability: YES (Intel SSBD)
  * L1 data cache invalidation
    * FLUSH_CMD MSR is available: YES
  * 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 explicitly indicates not being vulnerable to Variant 4 (SSB_NO): NO
  * Hypervisor indicates host CPU might be vulnerable to RSB underflow (RSBA): NO
  * CPU microcode is known to cause stability problems: NO (model 0x2d family 0x6 stepping 0x7 ucode 0x1 cpuid 0x206d7)
  * CPU microcode is the latest known available version: NO (latest known version is 0x714 according to Intel Microcode Guidance, August 8 2018)
* CPU vulnerability to the speculative execution attack variants
  * Vulnerable to Variant 1: YES
  * Vulnerable to Variant 2: YES
  * Vulnerable to Variant 3: YES
  * Vulnerable to Variant 3a: YES
  * Vulnerable to Variant 4: YES
  * Vulnerable to Variant l1tf: YES

CVE-2017-5753 [bounds check bypass] aka 'Spectre Variant 1'
* Mitigated according to the /sys interface: YES (Mitigation: __user pointer sanitization)
* Kernel has array_index_mask_nospec: YES (1 occurrence(s) found of x86 64 bits array_index_mask_nospec())
* Kernel has the Red Hat/Ubuntu patch: NO
* Kernel has mask_nospec64 (arm64): NO
> STATUS: NOT VULNERABLE (Mitigation: __user pointer sanitization)

CVE-2017-5715 [branch target injection] aka 'Spectre Variant 2'
* Mitigated according to the /sys interface: YES (Mitigation: Full generic retpoline, IBPB, IBRS_FW)
* Mitigation 1
  * Kernel is compiled with IBRS support: YES
    * IBRS enabled and active: YES (for kernel and firmware code)
  * Kernel is compiled with IBPB support: YES
    * IBPB enabled and active: YES
* Mitigation 2
  * Kernel has branch predictor hardening (arm): NO
  * Kernel compiled with retpoline option: YES
    * Kernel compiled with a retpoline-aware compiler: YES (kernel reports full retpoline compilation)
> STATUS: NOT VULNERABLE (Full retpoline + IBPB are mitigating the vulnerability)

CVE-2017-5754 [rogue data cache load] aka 'Meltdown' aka 'Variant 3'
* Mitigated according to the /sys interface: YES (Mitigation: PTI)
* Kernel supports Page Table Isolation (PTI): YES
  * PTI enabled and active: YES
  * Reduced performance impact of PTI: YES (CPU supports PCID, performance impact of PTI will be reduced)
* Running as a Xen PV DomU: NO
> STATUS: NOT VULNERABLE (Mitigation: PTI)

CVE-2018-3640 [rogue system register read] aka 'Variant 3a'
* CPU microcode mitigates the vulnerability: YES
> STATUS: NOT VULNERABLE (your CPU microcode mitigates the vulnerability)

CVE-2018-3639 [speculative store bypass] aka 'Variant 4'
* Mitigated according to the /sys interface: YES (Mitigation: Speculative Store Bypass disabled via prctl and seccomp)
* Kernel supports speculation store bypass: YES (found in /proc/self/status)
> STATUS: NOT VULNERABLE (Mitigation: Speculative Store Bypass disabled via prctl and seccomp)

CVE-2018-3615/3620/3646 [L1 terminal fault] aka 'Foreshadow & Foreshadow-NG'
* Mitigated according to the /sys interface: YES (Mitigation: PTE Inversion; VMX: conditional cache flushes, SMT vulnerable)
> STATUS: NOT VULNERABLE (Mitigation: PTE Inversion; VMX: conditional cache flushes, SMT vulnerable)

It shows that the microcode is not updated, and reports vulnerability.

If I understand correctly, the Linux VM should not install the microcode, but report the microcode features of the host.

     * CPU indicates STIBP capability: NO

Obviously stibp is not passed to the guest.

Is there any other/better way to pass the host cpu capabilities to the VM?