Re: [PATCH 3/5] Don't #VMEXIT(INTR) if we still have event_inj waiting

[Joerg Roedel <joro@8bytes.org>]

On Fri, Sep 18, 2009 at 03:00:30PM +0200, Alexander Graf wrote:
> Real hardware would first process the event_inj field and then notify the
> host that an interrupt is waiting.

Does it really? I couldn't find this in the SVM spec.

> Let's do the same and just not EXIT_INTR if we have an event pending for the
> L2 guest.

Anyway. I think this case is handled good enough with patch 5/5. This
patch, to be complete must also enable single-steping to exit again
after the first instruction of the exception handler has ran to inject
the interrupt. But that would make the whole thing rather compĺicated.

> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  arch/x86/kvm/svm.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 61efd13..28fcbd0 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -1401,6 +1401,10 @@ static inline int nested_svm_intr(struct vcpu_svm *svm)
>  	if (!(svm->vcpu.arch.hflags & HF_HIF_MASK))
>  		return 0;
>  
> +	/* We can't EXIT_INTR when we still have an event to inject */
> +	if (svm->vmcb->control.event_inj)
> +		return 1;
> +
>  	svm->vmcb->control.exit_code = SVM_EXIT_INTR;
>  
>  	if (nested_svm_exit_handled(svm)) {
> -- 
> 1.6.0.2
> 
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