Major KVM issues with kernel 4.5 on the host

On Sun, Mar 20, 2016 at 02:31:58PM +0100, Borislav Petkov wrote:
> On Sat, Mar 19, 2016 at 01:08:37AM +0100, Marc Haber wrote:
> > Booting Debian Linux, apt-get update, apt-get upgrade, and run aide
> > (which builds checksums for the entire filesystem, a rather disk-bound
> > activity).
> 
> So I did that and aide ran a whole init and check all the way through
> and all fine. I don't see anything out of the ordinary in your dmesg
> outputs either.
> 
> The next things we should look like is:
> 
> * diff .configs - there might be something there#

Here we go:

[2/501]mh@fan:~$ diff -u0 /boot/config-4.4.6-zgws1 /boot/config-4.5.1-zgws1

> * try to reproduce on debian testing or even stable. I have had similar
> issues with debian unstable in the past.

Gut feeling is that this is not the case. Why would it only appear on
VM hosts then? Debian unstable and testing are pretty close together
these days, and the issue is around for a month now in current
unstable. Btw, I am a DD, I know my way around debian and my gut
feeling is pretty well calibrated here.

I can try stable in the VM, but I'd rather not take the host out of
business. Would that help?

My CPU is also rather old:

processor       : 5
vendor_id       : AuthenticAMD
cpu family      : 16
model           : 10
model name      : AMD Phenom(tm) II X6 1090T Processor
stepping        : 0
microcode       : 0x10000dc
cpu MHz         : 1600.000
cache size      : 512 KB
physical id     : 0
siblings        : 6
core id         : 5
cpu cores       : 6
apicid          : 5
initial apicid  : 5
fpu             : yes
fpu_exception   : yes
cpuid level     : 6
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nopl nonstop_tsc extd_apicid aperfmperf pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt nodeid_msr cpb hw_pstate vmmcall npt lbrv svm_lock nrip_save pausefilter
bugs            : tlb_mmatch apic_c1e fxsave_leak sysret_ss_attrs
bogomips        : 6428.52
TLB size        : 1024 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 48 bits physical, 48 bits virtual
power management: ts ttp tm stc 100mhzsteps hwpstate cpb

afaik, this CPU is not affected by the current microcode issues, isn't
it? I do have the amd64-microcode package installed, which is supposed
to do everything automatically, and my initramfs doesn't have a
microcode "partition" prepended, gunzip | cpio -i gives the plain
initramfs contents directly.

Greetings
Marc

Major KVM issues with kernel 4.5 on the host

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