Re: [kvm-devel] Starting a VM reboots my machine

[Avi K. <av...@qu...>]

Andrea Arcangeli wrote:
> On Mon, Nov 05, 2007 at 04:25:00PM +0200, Avi Kivity wrote:
>   
>> This one's obviously correct, will apply...
>>     
>
> thanks!
>
>   
>>> Signed-off-by: Andrea Arcangeli <an...@su...>
>>>
>>> index 9584d0f..95a3489 100644
>>> --- a/drivers/kvm/svm.c
>>> +++ b/drivers/kvm/svm.c
>>> @@ -1459,11 +1459,6 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, 
>>> struct kvm_run *kvm_run)
>>>   	local_irq_enable();
>>>  -	vcpu->guest_mode = 1;
>>> -	if (vcpu->requests)
>>> -		if (test_and_clear_bit(KVM_TLB_FLUSH, &vcpu->requests))
>>> -		    svm_flush_tlb(vcpu);
>>> -
>>>  	asm volatile (
>>>  #ifdef CONFIG_X86_64
>>>  		"push %%rbp; \n\t"
>>>
>>>   
>>>       
>> Against which kvm is that? It isn't 2.6.24-rc, or kvm.git, or 2.6.23?
>>     
>
> I use the bleeding edge for userland and kernel, so kvm.git with "make
> sync".
>
>   

Well, I can't find anything like that it my tree.  Maybe something's stale?

>> Anyway, removing guest tlb flushing won't be good for the guest.
>>     
>
> Doesn't the common layer already take care of test_and_clearing that
> bitflag and calling kvm_x86_ops->tlb_flush before kvm_x86_ops->run in
> __vcpu_run? 

It does.

> I thought it was an obsolete piece of code (besides it
> doesn't compile anyway it would need to be changed KVM_REQ_TLB_FLUSH)
> and it got re-introduced by mistake with a merging error in the last
> commit.
>   

We're definitely looking at different trees.

-- 
Any sufficiently difficult bug is indistinguishable from a feature.