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* [PATCH] arm64: KVM: vgic-v3: Restore ICH_APR0Rn_EL2 before ICH_APR0Rn_EL2
@ 2016-02-17 15:35 Marc Zyngier
  2016-02-24 11:53 ` Christoffer Dall
  0 siblings, 1 reply; 2+ messages in thread
From: Marc Zyngier @ 2016-02-17 15:35 UTC (permalink / raw)
  To: Christoffer Dall; +Cc: linux-arm-kernel, kvmarm, kvm

The GICv3 architecture spec says:

Writing to the active priority registers in any order other than
the following order will result in UNPREDICTABLE behavior:
- ICH_AP0R<n>_EL2.
- ICH_AP1R<n>_EL2.

So let's not pointlessly go against the rule...

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm64/kvm/hyp/vgic-v3-sr.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index 9142e082..93f6c5c 100644
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -149,16 +149,6 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
 
 	switch (nr_pri_bits) {
 	case 7:
-		 write_gicreg(cpu_if->vgic_ap1r[3], ICH_AP1R3_EL2);
-		 write_gicreg(cpu_if->vgic_ap1r[2], ICH_AP1R2_EL2);
-	case 6:
-		 write_gicreg(cpu_if->vgic_ap1r[1], ICH_AP1R1_EL2);
-	default:
-		 write_gicreg(cpu_if->vgic_ap1r[0], ICH_AP1R0_EL2);
-	}	 	                           
-		 	                           
-	switch (nr_pri_bits) {
-	case 7:
 		 write_gicreg(cpu_if->vgic_ap0r[3], ICH_AP0R3_EL2);
 		 write_gicreg(cpu_if->vgic_ap0r[2], ICH_AP0R2_EL2);
 	case 6:
@@ -167,6 +157,16 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
 		 write_gicreg(cpu_if->vgic_ap0r[0], ICH_AP0R0_EL2);
 	}
 
+	switch (nr_pri_bits) {
+	case 7:
+		 write_gicreg(cpu_if->vgic_ap1r[3], ICH_AP1R3_EL2);
+		 write_gicreg(cpu_if->vgic_ap1r[2], ICH_AP1R2_EL2);
+	case 6:
+		 write_gicreg(cpu_if->vgic_ap1r[1], ICH_AP1R1_EL2);
+	default:
+		 write_gicreg(cpu_if->vgic_ap1r[0], ICH_AP1R0_EL2);
+	}	 	                           
+		 	                           
 	switch (max_lr_idx) {
 	case 15:
 		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(15)], ICH_LR15_EL2);
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] arm64: KVM: vgic-v3: Restore ICH_APR0Rn_EL2 before ICH_APR0Rn_EL2
  2016-02-17 15:35 [PATCH] arm64: KVM: vgic-v3: Restore ICH_APR0Rn_EL2 before ICH_APR0Rn_EL2 Marc Zyngier
@ 2016-02-24 11:53 ` Christoffer Dall
  0 siblings, 0 replies; 2+ messages in thread
From: Christoffer Dall @ 2016-02-24 11:53 UTC (permalink / raw)
  To: Marc Zyngier; +Cc: kvm, kvmarm, linux-arm-kernel

On Wed, Feb 17, 2016 at 03:35:12PM +0000, Marc Zyngier wrote:
> The GICv3 architecture spec says:
> 
> Writing to the active priority registers in any order other than
> the following order will result in UNPREDICTABLE behavior:
> - ICH_AP0R<n>_EL2.
> - ICH_AP1R<n>_EL2.
> 
> So let's not pointlessly go against the rule...
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
>  arch/arm64/kvm/hyp/vgic-v3-sr.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
> index 9142e082..93f6c5c 100644
> --- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
> +++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
> @@ -149,16 +149,6 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
>  
>  	switch (nr_pri_bits) {
>  	case 7:
> -		 write_gicreg(cpu_if->vgic_ap1r[3], ICH_AP1R3_EL2);
> -		 write_gicreg(cpu_if->vgic_ap1r[2], ICH_AP1R2_EL2);
> -	case 6:
> -		 write_gicreg(cpu_if->vgic_ap1r[1], ICH_AP1R1_EL2);
> -	default:
> -		 write_gicreg(cpu_if->vgic_ap1r[0], ICH_AP1R0_EL2);
> -	}	 	                           
> -		 	                           
> -	switch (nr_pri_bits) {
> -	case 7:
>  		 write_gicreg(cpu_if->vgic_ap0r[3], ICH_AP0R3_EL2);
>  		 write_gicreg(cpu_if->vgic_ap0r[2], ICH_AP0R2_EL2);
>  	case 6:
> @@ -167,6 +157,16 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
>  		 write_gicreg(cpu_if->vgic_ap0r[0], ICH_AP0R0_EL2);
>  	}
>  
> +	switch (nr_pri_bits) {
> +	case 7:
> +		 write_gicreg(cpu_if->vgic_ap1r[3], ICH_AP1R3_EL2);
> +		 write_gicreg(cpu_if->vgic_ap1r[2], ICH_AP1R2_EL2);
> +	case 6:
> +		 write_gicreg(cpu_if->vgic_ap1r[1], ICH_AP1R1_EL2);
> +	default:
> +		 write_gicreg(cpu_if->vgic_ap1r[0], ICH_AP1R0_EL2);
> +	}	 	                           
> +		 	                           

could you prune that extra pointless white space while you're at it?

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>

Thanks,
-Christoffer

>  	switch (max_lr_idx) {
>  	case 15:
>  		write_gicreg(cpu_if->vgic_lr[VGIC_V3_LR_INDEX(15)], ICH_LR15_EL2);
> -- 
> 2.1.4
> 

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2016-02-24 11:52 UTC | newest]

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2016-02-17 15:35 [PATCH] arm64: KVM: vgic-v3: Restore ICH_APR0Rn_EL2 before ICH_APR0Rn_EL2 Marc Zyngier
2016-02-24 11:53 ` Christoffer Dall

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