Re: Crash of guest with nested vmx with Unknown nested vmexit reason 80000021.

[Jeroen Groenewegen van der Weyden <groen692@grosc.com>]

Hi all,

Any input from my side necessary to keep this rolling?

BR,
Jeroen.

Tian, Kevin schreef op 7-10-2014 om 21:56:
> Add Yang as the nested vmx owner.
>
>> From: Jan Beulich [mailto:JBeulich@suse.com]
>> Sent: Tuesday, October 07, 2014 12:59 AM
>>
>>>>> On 30.09.14 at 17:55, <groen692@grosc.com> wrote:
>>> Recently I updated my openSuse box from 12.3 to 13.1. On this box I run
>>> xen with several guests. One of these guests is an appliance that has 4
>>> kvm guests running.
>>> When I start this appliance with the nested vmx feature the appliance
>>> crashes either immediately or after a few minutes.
>>>
>>> This same guest was running without a problem on opensuse releases 11.4
>>> until 12.3
>>> [...]
>>> ==== outup xl demsg
>>> (XEN) vvmx.c:2459:d5 Unknown nested vmexit reason 80000021.
>>> (XEN) Failed vm entry (exit reason 0x80000021) caused by invalid guest
>>> state (0).
>>> (XEN) ************* VMCS Area **************
>>> [...]
>> So the problem here is that
>>
>>> (XEN) Interruptibility=0008 ActivityState=0000
>> VMX_INTR_SHADOW_NMI is set while
>>
>>> (XEN) PinBased=0000003f CPUBased=b6b9e5fa SecondaryExec=000004eb
>> PIN_BASED_VIRTUAL_NMIS is active and
>>
>>> (XEN) VMEntry: intr_info=80000202 errcode=5d021101 ilen=00000003
>>> (XEN) VMExit: intr_info=00000000 errcode=00000000 ilen=00000003
>>> (XEN)         reason=80000021 qualification=00000000
>>> (XEN) IDTVectoring: info=80000202 errcode=00000000
>> an NMI is being injected. This case is explicitly mentioned in Vol 3
>> section 31.7.1.2 (Resuming Guest Software after Handling an
>> Exception). Either there needs to be extra code in vvmx.c to clear
>> VMX_INTR_SHADOW_NMI (as the second sub-bullet point of the last
>> bullet point says), or the second half of vmx_idtv_reinject() needs
>> to be done without regard to nestedhvm_vcpu_in_guestmode(v)
>> (and maybe also without regard to EXIT_REASON_TASK_SWITCH).
>>
>> Speaking of SDM sections: There are quite a few references in the
>> code that name just section numbers (in the case here, several
>> references to sections 25.7.1.* exist). These numbers become stale
>> quite quickly (here they're now 31.7.1.*), so in order to help
>> digging through issues like the one here, can I please ask one of
>> you to go through and replace (or at least amend) these numbers
>> with the sections' titles (which I hope won't get altered that quickly)?
>>
>> Jan
>
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