arm64: KVM: vgic-v3: Restore ICH_APR0Rn_EL2 before ICH_APR1Rn_EL2

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...

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index 9142e08..5dd2a26 100644 (file)
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -147,16 +147,6 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
        max_lr_idx = vtr_to_max_lr_idx(val);
        nr_pri_bits = vtr_to_nr_pri_bits(val);
 
-       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);
@@ -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);