[PATCH v15 19/37] KVM: arm64: CCA: Activate realms on first vCPU run

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

Use kvm_arch_vcpu_run_pid_change() to check if this is the first time
the realm guest has run. If this is the first run then activate the
realm.

Signed-off-by: Steven Price <steven.price@arm.com>

---
Changes since v12:
 * Fix commit message
 * Change realm_state checks to be >= REALM_STATE_ACTIVE to avoid a dead
   guest being revived by kvm_activate_realm().
---
 arch/arm64/include/asm/kvm_rmi.h |  1 +
 arch/arm64/kvm/arm.c             |  6 +++++
 arch/arm64/kvm/rmi.c             | 45 ++++++++++++++++++++++++++++++--
 3 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
index 5461c49bea4d..5cb99c187202 100644
--- a/arch/arm64/include/asm/kvm_rmi.h
+++ b/arch/arm64/include/asm/kvm_rmi.h
@@ -96,6 +96,7 @@ void kvm_init_rmi(void);
 u32 kvm_rmm_ipa_limit(void);
 
 int kvm_init_realm(struct kvm *kvm);
+int kvm_activate_realm(struct kvm *kvm);
 void kvm_destroy_realm(struct kvm *kvm);
 int kvm_realm_teardown_stage2(struct kvm *kvm);
 void kvm_destroy_rec(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 534d33b7c67a..df33322b8fea 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1034,6 +1034,12 @@ int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
 			return ret;
 	}
 
+	if (kvm_is_realm(vcpu->kvm)) {
+		ret = kvm_activate_realm(kvm);
+		if (ret)
+			return ret;
+	}
+
 	mutex_lock(&kvm->arch.config_lock);
 	set_bit(KVM_ARCH_FLAG_HAS_RAN_ONCE, &kvm->arch.flags);
 	mutex_unlock(&kvm->arch.config_lock);
diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
index 94776a9262c9..53b5b18f2275 100644
--- a/arch/arm64/kvm/rmi.c
+++ b/arch/arm64/kvm/rmi.c
@@ -687,7 +687,7 @@ static int realm_set_ipa_state(struct kvm_vcpu *vcpu,
 	return ret;
 }
 
-static int __maybe_unused realm_ensure_created(struct kvm *kvm)
+static int realm_ensure_created(struct kvm *kvm)
 {
 	lockdep_assert_held(&kvm->arch.config_lock);
 
@@ -793,7 +793,7 @@ int noinstr kvm_rec_enter(struct kvm_vcpu *vcpu)
 	return ret;
 }
 
-static int __maybe_unused kvm_create_rec(struct kvm_vcpu *vcpu)
+static int kvm_create_rec(struct kvm_vcpu *vcpu)
 {
 	struct user_pt_regs *vcpu_regs = vcpu_gp_regs(vcpu);
 	unsigned long mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
@@ -893,6 +893,47 @@ void kvm_destroy_rec(struct kvm_vcpu *vcpu)
 	rec->rec_page = NULL;
 }
 
+int kvm_activate_realm(struct kvm *kvm)
+{
+	struct realm *realm = &kvm->arch.realm;
+	struct kvm_vcpu *vcpu;
+	unsigned long i;
+	int ret;
+
+	if (kvm_realm_state(kvm) >= REALM_STATE_ACTIVE)
+		return 0;
+
+	if (!irqchip_in_kernel(kvm)) {
+		/* Userspace irqchip not yet supported with realms */
+		return -EOPNOTSUPP;
+	}
+
+	guard(mutex)(&kvm->arch.config_lock);
+	/* Check again with the lock held */
+	if (kvm_realm_state(kvm) >= REALM_STATE_ACTIVE)
+		return 0;
+
+	ret = realm_ensure_created(kvm);
+	if (ret)
+		return ret;
+
+	/* Mark state as dead in case we fail */
+	kvm_set_realm_state(kvm, REALM_STATE_DEAD);
+
+	kvm_for_each_vcpu(i, vcpu, kvm) {
+		ret = kvm_create_rec(vcpu);
+		if (ret)
+			return ret;
+	}
+
+	ret = rmi_realm_activate(virt_to_phys(realm->rd));
+	if (ret)
+		return -ENXIO;
+
+	kvm_set_realm_state(kvm, REALM_STATE_ACTIVE);
+	return 0;
+}
+
 void kvm_destroy_realm(struct kvm *kvm)
 {
 	struct realm *realm = &kvm->arch.realm;
-- 
2.43.0