KVM: arm/arm64: Get rid of vgic_elrsr

There is really no need to store the vgic_elrsr on the VGIC data
structures as the only need we have for the elrsr is to figure out if an
LR is inactive when we save the VGIC state upon returning from the
guest.  We can might as well store this in a temporary local variable.

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

virt/kvm/arm/hyp/vgic-v2-sr.c

@@ -23,29 +23,19 @@
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
 
-static void __hyp_text save_elrsr(struct kvm_vcpu *vcpu, void __iomem *base)
-{
-	struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
-	int nr_lr = (kern_hyp_va(&kvm_vgic_global_state))->nr_lr;
-	u32 elrsr0, elrsr1;
-
-	elrsr0 = readl_relaxed(base + GICH_ELRSR0);
-	if (unlikely(nr_lr > 32))
-		elrsr1 = readl_relaxed(base + GICH_ELRSR1);
-	else
-		elrsr1 = 0;
-
-	cpu_if->vgic_elrsr = ((u64)elrsr1 << 32) | elrsr0;
-}
-
 static void __hyp_text save_lrs(struct kvm_vcpu *vcpu, void __iomem *base)
 {
 	struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
-	int i;
 	u64 used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+	u64 elrsr;
+	int i;
+
+	elrsr = readl_relaxed(base + GICH_ELRSR0);
+	if (unlikely(used_lrs > 32))
+		elrsr |= ((u64)readl_relaxed(base + GICH_ELRSR1)) << 32;
 
 	for (i = 0; i < used_lrs; i++) {
-		if (cpu_if->vgic_elrsr & (1UL << i))
+		if (elrsr & (1UL << i))
 			cpu_if->vgic_lr[i] &= ~GICH_LR_STATE;
 		else
 			cpu_if->vgic_lr[i] = readl_relaxed(base + GICH_LR0 + (i * 4));
@@ -68,13 +58,9 @@ void __hyp_text __vgic_v2_save_state(struct kvm_vcpu *vcpu)
 
 	if (used_lrs) {
 		cpu_if->vgic_apr = readl_relaxed(base + GICH_APR);
-
-		save_elrsr(vcpu, base);
 		save_lrs(vcpu, base);
-
 		writel_relaxed(0, base + GICH_HCR);
 	} else {
-		cpu_if->vgic_elrsr = ~0UL;
 		cpu_if->vgic_apr = 0;
 	}
 }

virt/kvm/arm/hyp/vgic-v3-sr.c

@@ -222,15 +222,16 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
 	if (used_lrs) {
 		int i;
 		u32 nr_pre_bits;
+		u32 elrsr;
 
-		cpu_if->vgic_elrsr = read_gicreg(ICH_ELSR_EL2);
+		elrsr = read_gicreg(ICH_ELSR_EL2);
 
 		write_gicreg(0, ICH_HCR_EL2);
 		val = read_gicreg(ICH_VTR_EL2);
 		nr_pre_bits = vtr_to_nr_pre_bits(val);
 
 		for (i = 0; i < used_lrs; i++) {
-			if (cpu_if->vgic_elrsr & (1 << i))
+			if (elrsr & (1 << i))
 				cpu_if->vgic_lr[i] &= ~ICH_LR_STATE;
 			else
 				cpu_if->vgic_lr[i] = __gic_v3_get_lr(i);
@@ -262,7 +263,6 @@ void __hyp_text __vgic_v3_save_state(struct kvm_vcpu *vcpu)
 		    cpu_if->its_vpe.its_vm)
 			write_gicreg(0, ICH_HCR_EL2);
 
-		cpu_if->vgic_elrsr = 0xffff;
 		cpu_if->vgic_ap0r[0] = 0;
 		cpu_if->vgic_ap0r[1] = 0;
 		cpu_if->vgic_ap0r[2] = 0;

virt/kvm/arm/vgic/vgic-v2.c

@@ -265,7 +265,6 @@ void vgic_v2_enable(struct kvm_vcpu *vcpu)
 	 * anyway.
 	 */
 	vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr = 0;
-	vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr = ~0;
 
 	/* Get the show on the road... */
 	vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr = GICH_HCR_EN;

virt/kvm/arm/vgic/vgic-v3.c

@@ -267,7 +267,6 @@ void vgic_v3_enable(struct kvm_vcpu *vcpu)
 	 * anyway.
 	 */
 	vgic_v3->vgic_vmcr = 0;
-	vgic_v3->vgic_elrsr = ~0;
 
 	/*
 	 * If we are emulating a GICv3, we do it in an non-GICv2-compatible