evtchn: implement EVTCHNOP_set_priority and add the set_priority hook

Implement EVTCHNOP_set_priority.  A new set_priority hook added to
struct evtchn_port_ops will do the ABI specific validation and setup.

If an ABI does not provide a set_priority hook (as is the case of the
2-level ABI), the sub-op will return -ENOSYS.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>

2 files changed, 40 insertions, 0 deletions

diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 87bca94087..340bf32583 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -955,6 +955,27 @@ out:
     return rc;
 }
 
+static long evtchn_set_priority(const struct evtchn_set_priority *set_priority)
+{
+    struct domain *d = current->domain;
+    unsigned int port = set_priority->port;
+    long ret;
+
+    spin_lock(&d->event_lock);
+
+    if ( !port_is_valid(d, port) )
+    {
+        spin_unlock(&d->event_lock);
+        return -EINVAL;
+    }
+
+    ret = evtchn_port_set_priority(d, evtchn_from_port(d, port),
+                                   set_priority->priority);
+
+    spin_unlock(&d->event_lock);
+
+    return ret;
+}
 
 long do_event_channel_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 {
@@ -1064,6 +1085,14 @@ long do_event_channel_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         break;
     }
 
+    case EVTCHNOP_set_priority: {
+        struct evtchn_set_priority set_priority;
+        if ( copy_from_guest(&set_priority, arg, 1) != 0 )
+            return -EFAULT;
+        rc = evtchn_set_priority(&set_priority);
+        break;
+    }
+
     default:
         rc = -ENOSYS;
         break;
diff --git a/xen/include/xen/event.h b/xen/include/xen/event.h
index cba09e7a60..70fc271734 100644
--- a/xen/include/xen/event.h
+++ b/xen/include/xen/event.h
@@ -137,6 +137,8 @@ struct evtchn_port_ops {
     void (*unmask)(struct domain *d, struct evtchn *evtchn);
     bool_t (*is_pending)(struct domain *d, const struct evtchn *evtchn);
     bool_t (*is_masked)(struct domain *d, const struct evtchn *evtchn);
+    int (*set_priority)(struct domain *d, struct evtchn *evtchn,
+                        unsigned int priority);
     void (*print_state)(struct domain *d, const struct evtchn *evtchn);
 };
 
@@ -170,6 +172,15 @@ static inline bool_t evtchn_port_is_masked(struct domain *d,
     return d->evtchn_port_ops->is_masked(d, evtchn);
 }
 
+static inline int evtchn_port_set_priority(struct domain *d,
+                                           struct evtchn *evtchn,
+                                           unsigned int priority)
+{
+    if ( !d->evtchn_port_ops->set_priority )
+        return -ENOSYS;
+    return d->evtchn_port_ops->set_priority(d, evtchn, priority);
+}
+
 static inline void evtchn_port_print_state(struct domain *d,
                                            const struct evtchn *evtchn)
 {