Re: [PATCH 4/4] Nested SVM: Improve interrupt injection v2

[Gleb Natapov <gleb@redhat.com>]

On Mon, Jun 15, 2009 at 01:47:08PM +0200, Alexander Graf wrote:
>
> On 19.05.2009, at 15:22, Gleb Natapov wrote:
>
>> On Tue, May 19, 2009 at 12:54:03PM +0200, Alexander Graf wrote:
>>> While trying to get Hyper-V running, I realized that the interrupt  
>>> injection
>>> mechanisms that are in place right now are not 100% correct.
>>>
>>> This patch makes nested SVM's interrupt injection behave more like  
>>> on a
>>> real machine.
>>>
>>> v2 calls BUG_ON when svm_set_irq is called with GIF=0
>>>
>>> Signed-off-by: Alexander Graf <agraf@suse.de>
>>> ---
>>> arch/x86/kvm/svm.c |   39 ++++++++++++++++++++++++---------------
>>> 1 files changed, 24 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
>>> index fa2a710..5b14c9d 100644
>>> --- a/arch/x86/kvm/svm.c
>>> +++ b/arch/x86/kvm/svm.c
>>> @@ -1517,7 +1517,8 @@ static int nested_svm_vmexit_real(struct  
>>> vcpu_svm *svm, void *arg1,
>>> 	/* Kill any pending exceptions */
>>> 	if (svm->vcpu.arch.exception.pending == true)
>>> 		nsvm_printk("WARNING: Pending Exception\n");
>>> -	svm->vcpu.arch.exception.pending = false;
>>> +	kvm_clear_exception_queue(&svm->vcpu);
>>> +	kvm_clear_interrupt_queue(&svm->vcpu);
>>>
>> What about pending NMI here?
>
> NMI injected to the guest? That should have triggered by now and caused 
> an #NMI exit, no?
>
I don't really understand what this code is doing, but there are three
types of events exception/interrupt/nmi you clear only two of them. If
you are sure this is correct then OK.

--
			Gleb.