Re: [PATCH] KVM: SVM: Cleanup NMI singlestep

[Gleb Natapov <gleb@redhat.com>]

On Sun, Oct 18, 2009 at 01:24:54PM +0200, Jan Kiszka wrote:
> Push the NMI-related singlestep variable into vcpu_svm. It's dealing
> with an AMD-specific deficit, nothing generic for x86.
> 
> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Gleb Natapov <gleb@redhat.com>

> ---
> 
>  arch/x86/include/asm/kvm_host.h |    1 -
>  arch/x86/kvm/svm.c              |   12 +++++++-----
>  2 files changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index c6094f1..097a492 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -354,7 +354,6 @@ struct kvm_vcpu_arch {
>  	unsigned int time_offset;
>  	struct page *time_page;
>  
> -	bool singlestep; /* guest is single stepped by KVM */
>  	bool nmi_pending;
>  	bool nmi_injected;
>  
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 170b2d9..ffa6ad2 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -107,6 +107,8 @@ struct vcpu_svm {
>  	u32 *msrpm;
>  
>  	struct nested_state nested;
> +
> +	bool nmi_singlestep;
>  };
>  
>  /* enable NPT for AMD64 and X86 with PAE */
> @@ -1050,7 +1052,7 @@ static void update_db_intercept(struct kvm_vcpu *vcpu)
>  	svm->vmcb->control.intercept_exceptions &=
>  		~((1 << DB_VECTOR) | (1 << BP_VECTOR));
>  
> -	if (vcpu->arch.singlestep)
> +	if (svm->nmi_singlestep)
>  		svm->vmcb->control.intercept_exceptions |= (1 << DB_VECTOR);
>  
>  	if (vcpu->guest_debug & KVM_GUESTDBG_ENABLE) {
> @@ -1195,13 +1197,13 @@ static int db_interception(struct vcpu_svm *svm)
>  
>  	if (!(svm->vcpu.guest_debug &
>  	      (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP)) &&
> -		!svm->vcpu.arch.singlestep) {
> +		!svm->nmi_singlestep) {
>  		kvm_queue_exception(&svm->vcpu, DB_VECTOR);
>  		return 1;
>  	}
>  
> -	if (svm->vcpu.arch.singlestep) {
> -		svm->vcpu.arch.singlestep = false;
> +	if (svm->nmi_singlestep) {
> +		svm->nmi_singlestep = false;
>  		if (!(svm->vcpu.guest_debug & KVM_GUESTDBG_SINGLESTEP))
>  			svm->vmcb->save.rflags &=
>  				~(X86_EFLAGS_TF | X86_EFLAGS_RF);
> @@ -2543,7 +2545,7 @@ static void enable_nmi_window(struct kvm_vcpu *vcpu)
>  	/* Something prevents NMI from been injected. Single step over
>  	   possible problem (IRET or exception injection or interrupt
>  	   shadow) */
> -	vcpu->arch.singlestep = true;
> +	svm->nmi_singlestep = true;
>  	svm->vmcb->save.rflags |= (X86_EFLAGS_TF | X86_EFLAGS_RF);
>  	update_db_intercept(vcpu);
>  }
> 



--
			Gleb.