1 files changed, 40 insertions, 0 deletions

diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index f4edd6df3df2..7efd1cb9bb40 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -73,8 +73,12 @@ struct per_user_data {
 	wait_queue_head_t evtchn_wait;
 	struct fasync_struct *evtchn_async_queue;
 	const char *name;
+
+	domid_t restrict_domid;
 };
 
+#define UNRESTRICTED_DOMID ((domid_t)-1)
+
 struct user_evtchn {
 	struct rb_node node;
 	struct per_user_data *user;
@@ -443,6 +447,10 @@ static long evtchn_ioctl(struct file *file,
 		struct ioctl_evtchn_bind_virq bind;
 		struct evtchn_bind_virq bind_virq;
 
+		rc = -EACCES;
+		if (u->restrict_domid != UNRESTRICTED_DOMID)
+			break;
+
 		rc = -EFAULT;
 		if (copy_from_user(&bind, uarg, sizeof(bind)))
 			break;
@@ -468,6 +476,11 @@ static long evtchn_ioctl(struct file *file,
 		if (copy_from_user(&bind, uarg, sizeof(bind)))
 			break;
 
+		rc = -EACCES;
+		if (u->restrict_domid != UNRESTRICTED_DOMID &&
+		    u->restrict_domid != bind.remote_domain)
+			break;
+
 		bind_interdomain.remote_dom  = bind.remote_domain;
 		bind_interdomain.remote_port = bind.remote_port;
 		rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
@@ -485,6 +498,10 @@ static long evtchn_ioctl(struct file *file,
 		struct ioctl_evtchn_bind_unbound_port bind;
 		struct evtchn_alloc_unbound alloc_unbound;
 
+		rc = -EACCES;
+		if (u->restrict_domid != UNRESTRICTED_DOMID)
+			break;
+
 		rc = -EFAULT;
 		if (copy_from_user(&bind, uarg, sizeof(bind)))
 			break;
@@ -553,6 +570,27 @@ static long evtchn_ioctl(struct file *file,
 		break;
 	}
 
+	case IOCTL_EVTCHN_RESTRICT_DOMID: {
+		struct ioctl_evtchn_restrict_domid ierd;
+
+		rc = -EACCES;
+		if (u->restrict_domid != UNRESTRICTED_DOMID)
+			break;
+
+		rc = -EFAULT;
+		if (copy_from_user(&ierd, uarg, sizeof(ierd)))
+		    break;
+
+		rc = -EINVAL;
+		if (ierd.domid == 0 || ierd.domid >= DOMID_FIRST_RESERVED)
+			break;
+
+		u->restrict_domid = ierd.domid;
+		rc = 0;
+
+		break;
+	}
+
 	default:
 		rc = -ENOSYS;
 		break;
@@ -601,6 +639,8 @@ static int evtchn_open(struct inode *inode, struct file *filp)
 	mutex_init(&u->ring_cons_mutex);
 	spin_lock_init(&u->ring_prod_lock);
 
+	u->restrict_domid = UNRESTRICTED_DOMID;
+
 	filp->private_data = u;
 
 	return nonseekable_open(inode, filp);