1 files changed, 61 insertions, 2 deletions

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,
+};