Re: [PATCH] KVM: nVMX: Skip PF interception check when queuing during nested run

[Gleb Natapov <gleb@redhat.com>]

On Sun, Apr 28, 2013 at 09:24:41AM +0200, Jan Kiszka wrote:
> From: Jan Kiszka <jan.kiszka@siemens.com>
> 
> While a nested run is pending, vmx_queue_exception is only called to
> requeue exceptions that were previously picked up via
> vmx_cancel_injection. Therefore, we must not check for PF interception
> by L1, possibly causing a bogus nested vmexit.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Applied thanks. We should get rid of nested_run_pending state, but
re-executing instruction if emulation cannot be complete.

> ---
> 
> This and the KVM_REQ_IMMEDIATE_EXIT fix allows me to boot an L2 Linux
> without problems. Yongjie, please check if it resolves your issue(s) as
> well.
> 
>  arch/x86/kvm/vmx.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index d663a59..45eb949 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -1917,7 +1917,7 @@ static void vmx_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,
>  	u32 intr_info = nr | INTR_INFO_VALID_MASK;
>  
>  	if (nr == PF_VECTOR && is_guest_mode(vcpu) &&
> -		nested_pf_handled(vcpu))
> +	    !vmx->nested.nested_run_pending && nested_pf_handled(vcpu))
>  		return;
>  
>  	if (has_error_code) {
> -- 
> 1.7.3.4

--
			Gleb.