Re: [PATCH] KVM: VMX: Fix locking order in handle_invalid_guest_state

[Gleb Natapov <gleb@redhat.com>]

On Thu, Jul 30, 2009 at 02:16:30PM +0300, Avi Kivity wrote:
> On 07/29/2009 05:07 PM, Marcelo Tosatti wrote:
>>> The downside is that we're moving a vmx specific hack to common code.
>>>
>>> I think this could be simplified if interrupt injection happened outside
>>> the critical section.  This is needed anyway because emulated interrupt
>>> injection needs to access guest memory (IVT and the stack).
>>>      
>>
>> Why can't it happen now (outside of the critical section), other than
>> the kvm_vcpu_kick thing?
>>    
>
> I think there's little reason now.  One thing we need to do is make it  
> possible to call the injection code twice without entering the guest.  I  
> think right now it assumes nothing has been injected.
>
I Looked at this and it seems the current code handle this case.
Injection puts an event on a queue and if we haven't entered a guest
after this point on the next entry event is injected from the queue,
just like if injection failed due to IDT access.

What may happen is that at the time of irq injection there will be irq
with higher irr pending in APIC, But it looks like this already may
happen if injection failed on IDT access, but this is rare.

> We need either to cancel a previous injection (a variant of  
> vmx_complete_interrupts()), or avoid reinjecting  if we already did.
>
> -- 
> error compiling committee.c: too many arguments to function

--
			Gleb.