Re: [edk2] KVM: MTRR: fix memory type handling if MTRR is completely disabled

[Xiao Guangrong <guangrong.xiao@linux.intel.com>]

On 10/13/2015 02:20 AM, Xiao Guangrong wrote:
>
>
> On 10/11/2015 04:07 AM, Xiao Guangrong wrote:
>>
>>
>> On 10/02/2015 10:38 PM, Janusz wrote:
>>> W dniu 01.10.2015 o 16:18, Paolo Bonzini pisze:
>>>>
>>>> On 01/10/2015 16:12, Janusz wrote:
>>>>> Now, I can also add, that the problem is only when I allow VM to use
>>>>> more than one core, so with option  for example:
>>>>> -smp 8,cores=4,threads=2,sockets=1 and other combinations like -smp
>>>>> 4,threads=1 its not working, and without it I am always running VM
>>>>> without problems
>>>>>
>>>>> Any ideas what can it be? or any idea what would help to find out what
>>>>> is causing this?
>>>> I am going to send a revert of the patch tomorrow.
>>>>
>>>> Paolo
>>> Thanks, but revert patch doesn't help, so something else is wrong here
>>>
>>
>> It seems i can reproduce it now ... and finally i get little free time now :(
>> I will dig into it and fix it asap.
>>
>> Thank you, Janusz and Paolo!
>
> I think i have figured out the root case, i got these traces:
> <...>-47935 [052] d... 20017.763244: kvm_exit: reason EPT_VIOLATION rip 0xa0000 info 184 0
>             <...>-47935 [052] .... 20017.763244: kvm_page_fault: address a0000 error_code 184
>             <...>-47935 [052] .... 20017.763269: mark_mmio_spte: sptep:ffff880841c3d500 gfn a0
> access 6 gen fff94
>             <...>-47935 [052] .... 20017.763272: kvm_mmu_pagetable_walk: addr a0000 pferr 10 F
>             <...>-47935 [052] .... 20017.763272: kvm_mmu_paging_element: pte bfeff023 level 4
>             <...>-47935 [052] .... 20017.763273: kvm_mmu_paging_element: pte bff00023 level 3
>             <...>-47935 [052] .... 20017.763273: kvm_mmu_paging_element: pte e3 level 2
>             <...>-47935 [052] .... 20017.763274: kvm_emulate_insn: 0:a0000: (prot32)
>             <...>-47935 [052] .... 20017.763274: kvm_emulate_insn: 0:a0000: (prot32) failed
>             <...>-
> It told me that guest is executing on address 0xa0000 but it is a MMIO address, so KVM
> can not emulate it and complained with internal error.
>
> Actually, 0xa0000 is belong to SMRAM (0x30000 is SMRAM base and 0x80000 is EIP offset,
> 0x30000 + 0x80000 = 0xa0000), however, from QEMU's dump:

Wrong here...
Please ignore this mail... I definitely need some rest.