x86: add a shared page indicating the need for an EOI notification

To simplify the interface for the guest, when a guest uses this new
(sub-)hypercall, PHYSDEVOP_eoi behavior changes to unmask the
corresponding event channel at once, avoiding the eventual need for a
second hypercall from the guest.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/xen/common/event_channel.c b/xen/common/event_channel.c
index 3993df4bc5..09702e3d1f 100644
--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -762,10 +762,9 @@ long evtchn_bind_vcpu(unsigned int port, unsigned int vcpu_id)
 }
 
 
-static long evtchn_unmask(evtchn_unmask_t *unmask)
+int evtchn_unmask(unsigned int port)
 {
     struct domain *d = current->domain;
-    int            port = unmask->port;
     struct vcpu   *v;
 
     spin_lock(&d->event_lock);
@@ -916,7 +915,7 @@ long do_event_channel_op(int cmd, XEN_GUEST_HANDLE(void) arg)
         struct evtchn_unmask unmask;
         if ( copy_from_guest(&unmask, arg, 1) != 0 )
             return -EFAULT;
-        rc = evtchn_unmask(&unmask);
+        rc = evtchn_unmask(unmask.port);
         break;
     }