On Sun, May 12, 2013 at 6:29 PM, Abel Gordon <ABELG@xxxxxxxxxx> wrote:
>
>
> Kashyap Chamarthy <kashyap.cv@xxxxxxxxx> wrote on 12/05/2013 03:42:33 PM:
>
>> Again, sorry :(. I was just about to reply that this was physical host.
>>
>> I'm testing by disabling VMCS Shadowing per Jan Kiszka's suggestion,
>> and retrying. But I doubt that's the reason my L2 is seg-faulting. If
>> it still fails, I'll try to create a new L2 to see I can reproduce
>> more consistently.
>
> I doubt shadow-vmcs is related to this issue.
Indeed. I just re-tested w/o it, and it has no effect.
I'm trying a guest w/ newer kernel in L2.
> Note shadow vmcs is disabled unless you have a processor
> that supports this feature. Do you ?!
Yes, I noted this in my previous email. I'm using Intel Haswell.
Here's the info from MSR bits on the machine(From `Table 35-3`, MSRs
in Procesors Based on Intel Core Microarchitecture, `Volume 3C of the
SDM )
--------------------------------------------
# Read msr value
$ rdmsr 0x48B
7cff00000000
# Check Shadow VMCS is enabled:
$ rdmsr 0x00000485
300481e5
--------------------------------------------
And, on the Kernel command line:
--------------------------------------------
# nested
$ cat /sys/module/kvm_intel/parameters/nested
Y
# shadow VMCS
$ cat /sys/module/kvm_intel/parameters/enable_shadow_vmcs
Y
--------------------------------------------
Just for reference, here's the detailed procedure I noted while
testing it on Haswell --
https://raw.github.com/kashyapc/nvmx-haswell/master/SETUP-nVMX.rst
Also note you can disable
> shadow-vmcs using the kvm-intel kernel module parameter
> "enable_shadow_vmcs".
Yes, to test w/o shadow VMCS, I disabled it by adding "options
kvm-intel enable_shadow_vmcs=y" to /etc/modprobe.d/dist.conf & reboot
the host.
>
> Anyway, if you conclude this is related to shadow-vmcs let me know and
> I'll try to help.
So, from the above info shadow-vmcs is ruled-out. I'm trying to
investigate further, will post details if I have new findings.
Thank you for your help.
/kashyap
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