[PATCH v2 25/36] KVM: arm64: gic-v5: Reset vcpu state

[Sascha Bischoff]

Limit the number of ID and priority bits supported based on the
hardware capabilities when resetting the vcpu state.

Signed-off-by: Sascha Bischoff <sascha.bischoff at arm.com>
---
 arch/arm64/kvm/vgic/vgic-init.c |  6 +++++-
 arch/arm64/kvm/vgic/vgic-v5.c   | 30 ++++++++++++++++++++++++++++++
 arch/arm64/kvm/vgic/vgic.h      |  1 +
 3 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index afb5888cd8219..56cd5c05742df 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -396,7 +396,11 @@ int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
 
 static void kvm_vgic_vcpu_reset(struct kvm_vcpu *vcpu)
 {
-	if (kvm_vgic_global_state.type == VGIC_V2)
+	const struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+
+	if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V5)
+		vgic_v5_reset(vcpu);
+	else if (kvm_vgic_global_state.type == VGIC_V2)
 		vgic_v2_reset(vcpu);
 	else
 		vgic_v3_reset(vcpu);
diff --git a/arch/arm64/kvm/vgic/vgic-v5.c b/arch/arm64/kvm/vgic/vgic-v5.c
index 17001b06af600..feba175a5047d 100644
--- a/arch/arm64/kvm/vgic/vgic-v5.c
+++ b/arch/arm64/kvm/vgic/vgic-v5.c
@@ -56,6 +56,36 @@ int vgic_v5_probe(const struct gic_kvm_info *info)
 	return 0;
 }
 
+void vgic_v5_reset(struct kvm_vcpu *vcpu)
+{
+	u64 idr0;
+
+	idr0 = read_sysreg_s(SYS_ICC_IDR0_EL1);
+	switch (FIELD_GET(ICC_IDR0_EL1_ID_BITS, idr0)) {
+	case ICC_IDR0_EL1_ID_BITS_16BITS:
+		vcpu->arch.vgic_cpu.num_id_bits = 16;
+		break;
+	case ICC_IDR0_EL1_ID_BITS_24BITS:
+		vcpu->arch.vgic_cpu.num_id_bits = 24;
+		break;
+	default:
+		pr_warn("unknown value for id_bits");
+		vcpu->arch.vgic_cpu.num_id_bits = 16;
+	}
+
+	switch (FIELD_GET(ICC_IDR0_EL1_PRI_BITS, idr0)) {
+	case ICC_IDR0_EL1_PRI_BITS_4BITS:
+		vcpu->arch.vgic_cpu.num_pri_bits = 4;
+		break;
+	case ICC_IDR0_EL1_PRI_BITS_5BITS:
+		vcpu->arch.vgic_cpu.num_pri_bits = 5;
+		break;
+	default:
+		pr_warn("unknown value for priority_bits");
+		vcpu->arch.vgic_cpu.num_pri_bits = 4;
+	}
+}
+
 int vgic_v5_init(struct kvm *kvm)
 {
 	struct kvm_vcpu *vcpu;
diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h
index f974b55fb8058..c8ff545e777c2 100644
--- a/arch/arm64/kvm/vgic/vgic.h
+++ b/arch/arm64/kvm/vgic/vgic.h
@@ -386,6 +386,7 @@ void vgic_debug_destroy(struct kvm *kvm);
 
 int vgic_v5_probe(const struct gic_kvm_info *info);
 void vgic_v5_get_implemented_ppis(void);
+void vgic_v5_reset(struct kvm_vcpu *vcpu);
 int vgic_v5_init(struct kvm *kvm);
 int vgic_v5_map_resources(struct kvm *kvm);
 void vgic_v5_set_ppi_ops(struct vgic_irq *irq);
-- 
2.34.1