Re: kvm_intel fails to load on Conroe CPUs running Linux 4.12

[Sebastian Rachuj]

On 06.08.2017 23:10, Paolo Bonzini wrote:
> On 05/08/2017 21:26, Sebastian Rachuj wrote:
> > Dear linux developers,
> >
> > since my upgrade from linux 4.11 to linux 4.12 the "kvm_intel" module
> > does not load correctly anymore. "Modprobing" the kernel module gives an
> > Input/Output error. It seems to be related to the CPU architecture and
> > (to my knowledge) affects Conroe CPUs. I did a bisect and found the
> > following commit as the guilty one:
>
> What is your cpuinfo?  I tested on a Conroe Xeon X3220 (family 6,
> model 15, stepping 11) when I posted that patch, and it did have virtual
> NMIs.

Thank you for looking into the issue. My cpuinfo is as follows:

$ cat /proc/cpuinfo
processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 15
model name	: Intel(R) Core(TM)2 CPU          6420  @ 2.13GHz
stepping	: 6
microcode	: 0xc6
cpu MHz		: 2128.000
cache size	: 4096 KB
physical id	: 0
siblings	: 2
core id		: 0
cpu cores	: 2
apicid		: 0
initial apicid	: 0
fpu		: yes
fpu_exception	: yes
cpuid level	: 10
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov 
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm 
constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni 
dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm 
tpr_shadow dtherm
bugs		:
bogomips	: 4275.23
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management:

processor	: 1
vendor_id	: GenuineIntel
cpu family	: 6
model		: 15
model name	: Intel(R) Core(TM)2 CPU          6420  @ 2.13GHz
stepping	: 6
microcode	: 0xc6
cpu MHz		: 2128.000
cache size	: 4096 KB
physical id	: 0
siblings	: 2
core id		: 1
cpu cores	: 2
apicid		: 1
initial apicid	: 1
fpu		: yes
fpu_exception	: yes
cpuid level	: 10
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov 
pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm 
constant_tsc arch_perfmon pebs bts rep_good nopl cpuid aperfmperf pni 
dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm 
tpr_shadow dtherm
bugs		:
bogomips	: 4275.05
clflush size	: 64
cache_alignment	: 64
address sizes	: 36 bits physical, 48 bits virtual
power management: