[PATCH v16 30/45] KVM: arm64: CCA: Handle realm vCPU load

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

When loading a realm VCPU much of the work is handled by the RMM so only
some of the actions are required. Rearrange kvm_arch_vcpu_load()
slightly so we can bail out early for a realm guest.

Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/arm64/kvm/arm.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index f1b26b263bf0..96e536d2dda8 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -707,7 +707,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	struct kvm_s2_mmu *mmu;
 	int *last_ran;
 
-	if (is_protected_kvm_enabled())
+	if (is_protected_kvm_enabled() || kvm_is_realm(vcpu->kvm))
 		goto nommu;
 
 	if (vcpu_has_nv(vcpu))
@@ -751,12 +751,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 	kvm_vgic_load(vcpu);
 	kvm_vcpu_load_debug(vcpu);
 	kvm_vcpu_load_fgt(vcpu);
-	if (has_vhe())
-		kvm_vcpu_load_vhe(vcpu);
-	kvm_arch_vcpu_load_fp(vcpu);
-	kvm_vcpu_pmu_restore_guest(vcpu);
-	if (kvm_arm_is_pvtime_enabled(&vcpu->arch))
-		kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu);
 
 	if (kvm_vcpu_should_clear_twe(vcpu))
 		vcpu->arch.hcr_el2 &= ~HCR_TWE;
@@ -778,6 +772,17 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 			     &vcpu->arch.vgic_cpu.vgic_v3);
 	}
 
+	/* No additional state needs to be loaded on Realmed VMs */
+	if (vcpu_is_rec(vcpu))
+		return;
+
+	if (has_vhe())
+		kvm_vcpu_load_vhe(vcpu);
+	kvm_arch_vcpu_load_fp(vcpu);
+	kvm_vcpu_pmu_restore_guest(vcpu);
+	if (kvm_arm_is_pvtime_enabled(&vcpu->arch))
+		kvm_make_request(KVM_REQ_RECORD_STEAL, vcpu);
+
 	if (!cpumask_test_cpu(cpu, vcpu->kvm->arch.supported_cpus))
 		vcpu_set_on_unsupported_cpu(vcpu);
 
-- 
2.43.0