1 files changed, 43 insertions, 18 deletions

diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index 1f33e71c2a73..1e680ad6e863 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -84,15 +84,40 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 		!kvm_vgic_global_state.can_emulate_gicv2)
 		return -ENODEV;
 
-	/* Must be held to avoid race with vCPU creation */
+	/*
+	 * Ensure mutual exclusion with vCPU creation and any vCPU ioctls by:
+	 *
+	 *  - Holding kvm->lock to prevent KVM_CREATE_VCPU from reaching
+	 *    kvm_arch_vcpu_precreate() and ensuring created_vcpus is stable.
+	 *    This alone is insufficient, as kvm_vm_ioctl_create_vcpu() drops
+	 *    the kvm->lock before completing the vCPU creation.
+	 */
 	lockdep_assert_held(&kvm->lock);
 
+	/*
+	 *  - Acquiring the vCPU mutex for every *online* vCPU to prevent
+	 *    concurrent vCPU ioctls for vCPUs already visible to userspace.
+	 */
 	ret = -EBUSY;
-	if (!lock_all_vcpus(kvm))
+	if (kvm_trylock_all_vcpus(kvm))
 		return ret;
 
+	/*
+	 *  - Taking the config_lock which protects VGIC data structures such
+	 *    as the per-vCPU arrays of private IRQs (SGIs, PPIs).
+	 */
 	mutex_lock(&kvm->arch.config_lock);
 
+	/*
+	 * - Bailing on the entire thing if a vCPU is in the middle of creation,
+	 *   dropped the kvm->lock, but hasn't reached kvm_arch_vcpu_create().
+	 *
+	 * The whole combination of this guarantees that no vCPU can get into
+	 * KVM with a VGIC configuration inconsistent with the VM's VGIC.
+	 */
+	if (kvm->created_vcpus != atomic_read(&kvm->online_vcpus))
+		goto out_unlock;
+
 	if (irqchip_in_kernel(kvm)) {
 		ret = -EEXIST;
 		goto out_unlock;
@@ -132,6 +157,7 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 
 	kvm->arch.vgic.in_kernel = true;
 	kvm->arch.vgic.vgic_model = type;
+	kvm->arch.vgic.implementation_rev = KVM_VGIC_IMP_REV_LATEST;
 
 	kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
 
@@ -140,9 +166,12 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
 	else
 		INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
 
+	if (type == KVM_DEV_TYPE_ARM_VGIC_V3)
+		kvm->arch.vgic.nassgicap = system_supports_direct_sgis();
+
 out_unlock:
 	mutex_unlock(&kvm->arch.config_lock);
-	unlock_all_vcpus(kvm);
+	kvm_unlock_all_vcpus(kvm);
 	return ret;
 }
 
@@ -366,11 +395,10 @@ int vgic_init(struct kvm *kvm)
 		goto out;
 
 	/*
-	 * If we have GICv4.1 enabled, unconditionally request enable the
-	 * v4 support so that we get HW-accelerated vSGIs. Otherwise, only
-	 * enable it if we present a virtual ITS to the guest.
+	 * Ensure vPEs are allocated if direct IRQ injection (e.g. vSGIs,
+	 * vLPIs) is supported.
 	 */
-	if (vgic_supports_direct_msis(kvm)) {
+	if (vgic_supports_direct_irqs(kvm)) {
 		ret = vgic_v4_init(kvm);
 		if (ret)
 			goto out;
@@ -384,15 +412,7 @@ int vgic_init(struct kvm *kvm)
 		goto out;
 
 	vgic_debug_init(kvm);
-
-	/*
-	 * If userspace didn't set the GIC implementation revision,
-	 * default to the latest and greatest. You know want it.
-	 */
-	if (!dist->implementation_rev)
-		dist->implementation_rev = KVM_VGIC_IMP_REV_LATEST;
 	dist->initialized = true;
-
 out:
 	return ret;
 }
@@ -418,7 +438,7 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm)
 		dist->vgic_cpu_base = VGIC_ADDR_UNDEF;
 	}
 
-	if (vgic_supports_direct_msis(kvm))
+	if (vgic_supports_direct_irqs(kvm))
 		vgic_v4_teardown(kvm);
 
 	xa_destroy(&dist->lpi_xa);
@@ -649,10 +669,12 @@ void kvm_vgic_init_cpu_hardware(void)
 	 * We want to make sure the list registers start out clear so that we
 	 * only have the program the used registers.
 	 */
-	if (kvm_vgic_global_state.type == VGIC_V2)
+	if (kvm_vgic_global_state.type == VGIC_V2) {
 		vgic_v2_init_lrs();
-	else
+	} else if (kvm_vgic_global_state.type == VGIC_V3 ||
+		   kvm_vgic_global_state.has_gcie_v3_compat) {
 		kvm_call_hyp(__vgic_v3_init_lrs);
+	}
 }
 
 /**
@@ -697,6 +719,9 @@ int kvm_vgic_hyp_init(void)
 			kvm_info("GIC system register CPU interface enabled\n");
 		}
 		break;
+	case GIC_V5:
+		ret = vgic_v5_probe(gic_kvm_info);
+		break;
 	default:
 		ret = -ENODEV;
 	}