Re: [PART1 RFC v2 09/10] svm: Do not intercept CR8 when enable AVIC

[Paolo Bonzini]

On 04/03/2016 21:46, Suravee Suthikulpanit wrote:
> +
> +		/* Do not do cr8 intercept if AVIC is enabled. */

No need for this comment.

> +		svm_x86_ops.update_cr8_intercept = NULL;
>  	} else {
>  		svm_x86_ops.deliver_posted_interrupt = NULL;
>  	}
> @@ -1116,7 +1119,8 @@ static void init_vmcb(struct vcpu_svm *svm)
>  	set_cr_intercept(svm, INTERCEPT_CR0_WRITE);
>  	set_cr_intercept(svm, INTERCEPT_CR3_WRITE);
>  	set_cr_intercept(svm, INTERCEPT_CR4_WRITE);
> -	set_cr_intercept(svm, INTERCEPT_CR8_WRITE);
> +	if (!avic)

Remember that AVIC enabled/disabled must be refreshed when the
.refresh_apicv_exec_ctrl callback is invoked, so it is not enough to use
the global variable.

Paolo

> +		set_cr_intercept(svm, INTERCEPT_CR8_WRITE);
>  
>  	set_dr_intercepts(svm);
>  
> @@ -4277,7 +4281,8 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
>  {
>  	struct vcpu_svm *svm = to_svm(vcpu);
>  
> -	if (is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK))
> +	if ((is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK)) ||
> +	     avic)
>  		return;
>  
>  	clr_cr_intercept(svm, INTERCEPT_CR8_WRITE);
> @@ -4472,8 +4477,10 @@ static inline void sync_lapic_to_cr8(struct kvm_vcpu *vcpu)
>  	if (is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK))
>  		return;
>  
> -	cr8 = kvm_get_cr8(vcpu);
> -	svm->vmcb->control.v_tpr = cr8 & V_TPR_MASK;
> +	svm->vmcb->control.v_tpr = cr8 = kvm_get_cr8(vcpu) & V_TPR_MASK;
> +
> +	if (avic)
> +		*(avic_get_bk_page_entry(svm, APIC_TASKPRI)) = (u32)cr8 << 4;