[PATCH v2 15/17] arm64: KVM: vgic-v3: Do not save an LR known to be empty

[Christoffer Dall]

On Wed, Feb 17, 2016 at 04:40:47PM +0000, Marc Zyngier wrote:
> On exit, any empty LR will be signaled in ICH_ELRSR_EL2. Which
> means that we do not have to save it, and we can just clear
> its state in the in-memory copy.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
> ---
>  arch/arm64/kvm/hyp/vgic-v3-sr.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
> index 3463c0a..ff67296 100644
> --- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
> +++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
> @@ -190,8 +190,15 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
>  		save_maint_int_state(vcpu, max_lr_idx + 1);
>  
>  		for (i = 0; i <= max_lr_idx; i++) {
> -			if (vcpu->arch.vgic_cpu.live_lrs & (1UL << i))
> -				cpu_if->vgic_lr[i] = __gic_v3_get_lr(i);
> +			if (!(vcpu->arch.vgic_cpu.live_lrs & (1UL << i)))
> +				continue;
> +
> +			if (cpu_if->vgic_elrsr & (1 << i)) {
> +				cpu_if->vgic_lr[i] &= ~ICH_LR_STATE;
> +				continue;
> +			}
> +
> +			cpu_if->vgic_lr[i] = __gic_v3_get_lr(i);
>  		}
>  
>  		switch (nr_pri_bits) {
> -- 
> 2.1.4
> 

Reviewed-by: Christoffer Dall <christoffer.dall at linaro.org>