KVM: arm64: vgic-v3: Add ICV_IGNREN0_EL1 handler

Add a handler for reading/writing the guest's view of the ICC_IGRPEN0_EL1
register, which is located in the ICH_VMCR_EL2.VENG0 field.
Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>

arch/arm64/include/asm/sysreg.h

@@ -190,6 +190,7 @@
 #define SYS_ICC_BPR1_EL1		sys_reg(3, 0, 12, 12, 3)
 #define SYS_ICC_CTLR_EL1		sys_reg(3, 0, 12, 12, 4)
 #define SYS_ICC_SRE_EL1			sys_reg(3, 0, 12, 12, 5)
+#define SYS_ICC_GRPEN0_EL1		sys_reg(3, 0, 12, 12, 6)
 #define SYS_ICC_GRPEN1_EL1		sys_reg(3, 0, 12, 12, 7)
 
 #define SYS_CONTEXTIDR_EL1		sys_reg(3, 0, 13, 0, 1)

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

@@ -689,11 +689,28 @@ static void __hyp_text __vgic_v3_write_eoir(struct kvm_vcpu *vcpu, u32 vmcr, int
 	__vgic_v3_clear_active_lr(lr, lr_val);
 }
 
+static void __hyp_text __vgic_v3_read_igrpen0(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
+{
+	vcpu_set_reg(vcpu, rt, !!(vmcr & ICH_VMCR_ENG0_MASK));
+}
+
 static void __hyp_text __vgic_v3_read_igrpen1(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
 {
 	vcpu_set_reg(vcpu, rt, !!(vmcr & ICH_VMCR_ENG1_MASK));
 }
 
+static void __hyp_text __vgic_v3_write_igrpen0(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
+{
+	u64 val = vcpu_get_reg(vcpu, rt);
+
+	if (val & 1)
+		vmcr |= ICH_VMCR_ENG0_MASK;
+	else
+		vmcr &= ~ICH_VMCR_ENG0_MASK;
+
+	__vgic_v3_write_vmcr(vmcr);
+}
+
 static void __hyp_text __vgic_v3_write_igrpen1(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
 {
 	u64 val = vcpu_get_reg(vcpu, rt);
@@ -910,6 +927,12 @@ int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
 	case SYS_ICC_HPPIR1_EL1:
 		fn = __vgic_v3_read_hppir;
 		break;
+	case SYS_ICC_GRPEN0_EL1:
+		if (is_read)
+			fn = __vgic_v3_read_igrpen0;
+		else
+			fn = __vgic_v3_write_igrpen0;
+		break;
 	case SYS_ICC_BPR0_EL1:
 		if (is_read)
 			fn = __vgic_v3_read_bpr0;