[Xen-devel] [PATCHv2 4/5] evtchn: remove the locking when unmasking an event channel

[David Vrabel <david.vrabel@xxxxxxxxxx>]

The event channel lock is no longer required to check if the port is
valid.

Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
---
 xen/common/event_channel.c |    6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 416c76f..aa821ea 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -977,9 +977,7 @@ int evtchn_unmask(unsigned int port)
     struct domain *d = current->domain;
     struct evtchn *evtchn;
 
-    ASSERT(spin_is_locked(&d->event_lock));
-
-    if ( unlikely(!port_is_valid(d, port)) )
+    if ( port >= read_atomic(&d->valid_evtchns) )
         return -EINVAL;
 
     evtchn = evtchn_from_port(d, port);
@@ -1145,9 +1143,7 @@ long do_event_channel_op(int cmd, 
XEN_GUEST_HANDLE_PARAM(void) arg)
         struct evtchn_unmask unmask;
         if ( copy_from_guest(&unmask, arg, 1) != 0 )
             return -EFAULT;
-        spin_lock(&current->domain->event_lock);
         rc = evtchn_unmask(unmask.port);
-        spin_unlock(&current->domain->event_lock);
         break;
     }
 
-- 
1.7.10.4


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