6 files changed, 79 insertions, 2 deletions

diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt
new file mode 100644
index 000000000000..38f27f709a99
--- /dev/null
+++ b/Documentation/virtual/kvm/devices/arm-vgic.txt
@@ -0,0 +1,10 @@
+ARM Virtual Generic Interrupt Controller (VGIC)
+===============================================
+
+Device types supported:
+  KVM_DEV_TYPE_ARM_VGIC_V2     ARM Generic Interrupt Controller v2.0
+
+Only one VGIC instance may be instantiated through either this API or the
+legacy KVM_CREATE_IRQCHIP api.  The created VGIC will act as the VM interrupt
+controller, requiring emulated user-space devices to inject interrupts to the
+VGIC instead of directly to CPUs.
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index c9fe9d71be73..cc7c41af9c38 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -190,6 +190,7 @@ int kvm_dev_ioctl_check_extension(long ext)
         case KVM_CAP_IRQCHIP:
                 r = vgic_present;
                 break;
+        case KVM_CAP_DEVICE_CTRL:
         case KVM_CAP_USER_MEMORY:
         case KVM_CAP_SYNC_MMU:
         case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 4ecf10775c4f..1f46f66f60ab 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1075,6 +1075,7 @@ struct kvm_device *kvm_device_from_filp(struct file *filp);
 extern struct kvm_device_ops kvm_mpic_ops;
 extern struct kvm_device_ops kvm_xics_ops;
 extern struct kvm_device_ops kvm_vfio_ops;
+extern struct kvm_device_ops kvm_arm_vgic_v2_ops;
 
 #ifdef CONFIG_HAVE_KVM_CPU_RELAX_INTERCEPT
 
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 902f12461873..b647c2917391 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -853,6 +853,7 @@ struct kvm_device_attr {
 #define  KVM_DEV_VFIO_GROUP                     1
 #define   KVM_DEV_VFIO_GROUP_ADD                        1
 #define   KVM_DEV_VFIO_GROUP_DEL                        2
+#define KVM_DEV_TYPE_ARM_VGIC_V2        5
 
 /*
  * ioctls for VM fds
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 5e9df47778fb..b15d6c17a090 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1433,20 +1433,45 @@ out:
 
 int kvm_vgic_create(struct kvm *kvm)
 {
-        int ret = 0;
+        int i, vcpu_lock_idx = -1, ret = 0;
+        struct kvm_vcpu *vcpu;
 
         mutex_lock(&kvm->lock);
 
-        if (atomic_read(&kvm->online_vcpus) || kvm->arch.vgic.vctrl_base) {
+        if (kvm->arch.vgic.vctrl_base) {
                 ret = -EEXIST;
                 goto out;
         }
 
+        /*
+         * Any time a vcpu is run, vcpu_load is called which tries to grab the
+         * vcpu->mutex.  By grabbing the vcpu->mutex of all VCPUs we ensure
+         * that no other VCPUs are run while we create the vgic.
+         */
+        kvm_for_each_vcpu(i, vcpu, kvm) {
+                if (!mutex_trylock(&vcpu->mutex))
+                        goto out_unlock;
+                vcpu_lock_idx = i;
+        }
+
+        kvm_for_each_vcpu(i, vcpu, kvm) {
+                if (vcpu->arch.has_run_once) {
+                        ret = -EBUSY;
+                        goto out_unlock;
+                }
+        }
+
         spin_lock_init(&kvm->arch.vgic.lock);
         kvm->arch.vgic.vctrl_base = vgic_vctrl_base;
         kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
         kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
 
+out_unlock:
+        for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
+                vcpu = kvm_get_vcpu(kvm, vcpu_lock_idx);
+                mutex_unlock(&vcpu->mutex);
+        }
+
 out:
         mutex_unlock(&kvm->lock);
         return ret;
@@ -1510,3 +1535,37 @@ int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr)
         mutex_unlock(&kvm->lock);
         return r;
 }
+
+static int vgic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+{
+        return -ENXIO;
+}
+
+static int vgic_get_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+{
+        return -ENXIO;
+}
+
+static int vgic_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
+{
+        return -ENXIO;
+}
+
+static void vgic_destroy(struct kvm_device *dev)
+{
+        kfree(dev);
+}
+
+static int vgic_create(struct kvm_device *dev, u32 type)
+{
+        return kvm_vgic_create(dev->kvm);
+}
+
+struct kvm_device_ops kvm_arm_vgic_v2_ops = {
+        .name = "kvm-arm-vgic",
+        .create = vgic_create,
+        .destroy = vgic_destroy,
+        .set_attr = vgic_set_attr,
+        .get_attr = vgic_get_attr,
+        .has_attr = vgic_has_attr,
+};
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 03c97e7ae4ca..3efba97bdce2 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2273,6 +2273,11 @@ static int kvm_ioctl_create_device(struct kvm *kvm,
                 ops = &kvm_vfio_ops;
                 break;
 #endif
+#ifdef CONFIG_KVM_ARM_VGIC
+        case KVM_DEV_TYPE_ARM_VGIC_V2:
+                ops = &kvm_arm_vgic_v2_ops;
+                break;
+#endif
         default:
                 return -ENODEV;
         }