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

[Janusz <januszmk6@gmail.com>]

I was able to run my virtual machine with this, but had very high cpu
usage when something happen in it like booting system. once, my virtual
machine hang and I couln't even get my mouse / keyboard back from qemu.
When I did vga passthrough, I didn't get any video output, and cpu usage
was also high. Tried it on 4.3

W dniu 14.10.2015 o 05:58, Xiao Guangrong pisze:
>
> Janusz,
>
> Could you please try this:
>
> $ git diff
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 185fc16..bdd564f 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -4957,12 +4957,14 @@ static int handle_emulation_failure(struct
> kvm_vcpu *vcpu)
>
>         ++vcpu->stat.insn_emulation_fail;
>         trace_kvm_emulate_insn_failed(vcpu);
> +#if 0
>         if (!is_guest_mode(vcpu) && kvm_x86_ops->get_cpl(vcpu) == 0) {
>                 vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
>                 vcpu->run->internal.suberror =
> KVM_INTERNAL_ERROR_EMULATION;
>                 vcpu->run->internal.ndata = 0;
>                 r = EMULATE_FAIL;
>         }
> +#endif
>         kvm_queue_exception(vcpu, UD_VECTOR);
>
>         return r;
>
> To see if the issue still there?
>
>
> 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
>>