arm64: KVM: vgic-v3: Only wipe LRs on vcpu exit

So far, we're always writing all possible LRs, setting the empty
ones with a zero value. This is obvious doing a low of work for
nothing, and we're better off clearing those we've actually
dirtied on the exit path (it is very rare to inject more than one
interrupt at a time anyway).

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

1 files changed, 4 insertions, 5 deletions

diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index 81349479e17c..fff7cd42b3a3 100644
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -196,6 +196,7 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
                         }
 
                         cpu_if->vgic_lr[i] = __gic_v3_get_lr(i);
+                        __gic_v3_set_lr(0, i);
                 }
 
                 switch (nr_pri_bits) {
@@ -293,12 +294,10 @@ void __hyp_text __vgic_v3_restore_state(struct kvm_vcpu *vcpu)
                 }
 
                 for (i = 0; i <= max_lr_idx; i++) {
-                        val = 0;
-
-                        if (live_lrs & (1 << i))
-                                val = cpu_if->vgic_lr[i];
+                        if (!(live_lrs & (1 << i)))
+                                continue;
 
-                        __gic_v3_set_lr(val, i);
+                        __gic_v3_set_lr(cpu_if->vgic_lr[i], i);
                 }
         }