[PATCH v2 11/45] KVM: arm64: GICv3: Decouple ICH_HCR_EL2 programming from LRs

[Marc Zyngier <maz@kernel.org>]

Not programming ICH_HCR_EL2 while no LRs are populated is a bit
of an issue, as we otherwise don't see any maintenance interrupt
when the guest interacts with the LRs.

Decouple the two and always program the control register, even when
we don't have to touch the LRs.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/hyp/vgic-v3-sr.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index aa04cc9cdc1ab..d001b26a21f16 100644
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -219,20 +219,12 @@ void __vgic_v3_save_state(struct vgic_v3_cpu_if *cpu_if)
 		}
 	}
 
-	if (used_lrs || cpu_if->its_vpe.its_vm) {
+	if (used_lrs) {
 		int i;
 		u32 elrsr;
 
 		elrsr = read_gicreg(ICH_ELRSR_EL2);
 
-		if (cpu_if->vgic_hcr & ICH_HCR_EL2_LRENPIE) {
-			u64 val = read_gicreg(ICH_HCR_EL2);
-			cpu_if->vgic_hcr &= ~ICH_HCR_EL2_EOIcount;
-			cpu_if->vgic_hcr |= val & ICH_HCR_EL2_EOIcount;
-		}
-
-		write_gicreg(compute_ich_hcr(cpu_if) & ~ICH_HCR_EL2_En, ICH_HCR_EL2);
-
 		for (i = 0; i < used_lrs; i++) {
 			if (elrsr & (1 << i))
 				cpu_if->vgic_lr[i] &= ~ICH_LR_STATE;
@@ -242,6 +234,14 @@ void __vgic_v3_save_state(struct vgic_v3_cpu_if *cpu_if)
 			__gic_v3_set_lr(0, i);
 		}
 	}
+
+	if (cpu_if->vgic_hcr & ICH_HCR_EL2_LRENPIE) {
+		u64 val = read_gicreg(ICH_HCR_EL2);
+		cpu_if->vgic_hcr &= ~ICH_HCR_EL2_EOIcount;
+		cpu_if->vgic_hcr |= val & ICH_HCR_EL2_EOIcount;
+	}
+
+	write_gicreg(compute_ich_hcr(cpu_if) & ~ICH_HCR_EL2_En, ICH_HCR_EL2);
 }
 
 void __vgic_v3_restore_state(struct vgic_v3_cpu_if *cpu_if)
@@ -249,12 +249,10 @@ void __vgic_v3_restore_state(struct vgic_v3_cpu_if *cpu_if)
 	u64 used_lrs = cpu_if->used_lrs;
 	int i;
 
-	if (used_lrs || cpu_if->its_vpe.its_vm) {
-		write_gicreg(compute_ich_hcr(cpu_if), ICH_HCR_EL2);
+	write_gicreg(compute_ich_hcr(cpu_if), ICH_HCR_EL2);
 
-		for (i = 0; i < used_lrs; i++)
-			__gic_v3_set_lr(cpu_if->vgic_lr[i], i);
-	}
+	for (i = 0; i < used_lrs; i++)
+		__gic_v3_set_lr(cpu_if->vgic_lr[i], i);
 
 	/*
 	 * Ensure that writes to the LRs, and on non-VHE systems ensure that
-- 
2.47.3