[PATCH v16 19/45] KVM: arm64: CCA: Support the VGIC in realms

[Steven Price <steven.price@arm.com>]

The RMM provides emulation of a VGIC to the realm guest. With RMM v2.0
the registers are passed in the system registers so this works similar
to a normal guest, but kvm_arch_vcpu_put() need reordering to early out,
and realm guests don't support GICv2 even if the host does.

Signed-off-by: Steven Price <steven.price@arm.com>
---
Changes from v12:
 * GIC registers are now passed in the system registers rather than via
   rec_entry/rec_exit which removes most of the changes.
Changes from v11:
 * Minor changes to align with the previous patches. Note that the VGIC
   handling will change with RMM v2.0.
Changes from v10:
 * Make sure we sync the VGIC v4 state, and only populate valid lrs from
   the list.
Changes from v9:
 * Copy gicv3_vmcr from the RMM at the same time as gicv3_hcr rather
   than having to handle that as a special case.
Changes from v8:
 * Propagate gicv3_hcr to from the RMM.
Changes from v5:
 * Handle RMM providing fewer GIC LRs than the hardware supports.
---
 arch/arm64/kvm/arm.c            | 11 ++++++++---
 arch/arm64/kvm/vgic/vgic-init.c |  2 +-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 38fac98cd6a4..2959a1451232 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -791,19 +791,24 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 		kvm_call_hyp_nvhe(__pkvm_vcpu_put);
 	}
 
+	kvm_timer_vcpu_put(vcpu);
+	kvm_vgic_put(vcpu);
 	kvm_vcpu_put_debug(vcpu);
+
+	vcpu->cpu = -1;
+
+	if (vcpu_is_rec(vcpu))
+		return;
+
 	kvm_arch_vcpu_put_fp(vcpu);
 	if (has_vhe())
 		kvm_vcpu_put_vhe(vcpu);
-	kvm_timer_vcpu_put(vcpu);
-	kvm_vgic_put(vcpu);
 	kvm_vcpu_pmu_restore_host(vcpu);
 	if (vcpu_has_nv(vcpu))
 		kvm_vcpu_put_hw_mmu(vcpu);
 	kvm_arm_vmid_clear_active();
 
 	vcpu_clear_on_unsupported_cpu(vcpu);
-	vcpu->cpu = -1;
 }
 
 static void __kvm_arm_vcpu_power_off(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index 907057881b26..fd77db35ef02 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -81,7 +81,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	 * the proper checks already.
 	 */
 	if (type == KVM_DEV_TYPE_ARM_VGIC_V2 &&
-		!kvm_vgic_global_state.can_emulate_gicv2)
+	    (!kvm_vgic_global_state.can_emulate_gicv2 || kvm_is_realm(kvm)))
 		return -ENODEV;
 
 	/*
-- 
2.43.0