virtio: quick fix

Fixes a regression in virtio that's causing issues
 for many people.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

virtio: quick fix

Fixes a regression in virtio that's causing issues
for many people.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Wed 24 Jan 2018 17:20:24 GMT
# gpg:                using RSA key 0x281F0DB8D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream:
  Revert "qemu: add a cleanup callback function to EventNotifier"
  Revert "virtio: postpone the execution of event_notifier_cleanup function"
  Revert "virtio: improve virtio devices initialization time"

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

accel/kvm/kvm-all.c

@@ -812,10 +812,6 @@ static void kvm_mem_ioeventfd_del(MemoryListener *listener,
     if (r < 0) {
         abort();
     }
-
-    if (e->cleanup) {
-        e->cleanup(e);
-    }
 }
 
 static void kvm_io_ioeventfd_add(MemoryListener *listener,

hw/virtio/virtio-bus.c

@@ -256,15 +256,6 @@ bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus)
     return k->ioeventfd_assign && k->ioeventfd_enabled(proxy);
 }
 
-static void virtio_bus_cleanup_event_notifier(EventNotifier *notifier)
-{
-    /* Test and clear notifier after disabling event,
-     * in case poll callback didn't have time to run.
-     */
-    virtio_queue_host_notifier_read(notifier);
-    event_notifier_cleanup(notifier);
-}
-
 /*
  * This function switches ioeventfd on/off in the device.
  * The caller must set or clear the handlers for the EventNotifier.
@@ -292,13 +283,19 @@ int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
         r = k->ioeventfd_assign(proxy, notifier, n, true);
         if (r < 0) {
             error_report("%s: unable to assign ioeventfd: %d", __func__, r);
-            virtio_bus_cleanup_event_notifier(notifier);
+            goto cleanup_event_notifier;
         }
+        return 0;
     } else {
-        notifier->cleanup = virtio_bus_cleanup_event_notifier;
         k->ioeventfd_assign(proxy, notifier, n, false);
     }
 
+cleanup_event_notifier:
+    /* Test and clear notifier after disabling event,
+     * in case poll callback didn't have time to run.
+     */
+    virtio_queue_host_notifier_read(notifier);
+    event_notifier_cleanup(notifier);
     return r;
 }
 

hw/virtio/virtio.c

@@ -2574,7 +2574,6 @@ static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
     VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev)));
     int n, r, err;
 
-    memory_region_transaction_begin();
     for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
         VirtQueue *vq = &vdev->vq[n];
         if (!virtio_queue_get_num(vdev, n)) {
@@ -2597,7 +2596,6 @@ static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
         }
         event_notifier_set(&vq->host_notifier);
     }
-    memory_region_transaction_commit();
     return 0;
 
 assign_error:
@@ -2611,7 +2609,6 @@ assign_error:
         r = virtio_bus_set_host_notifier(qbus, n, false);
         assert(r >= 0);
     }
-    memory_region_transaction_commit();
     return err;
 }
 
@@ -2628,7 +2625,6 @@ static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev)
     VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev)));
     int n, r;
 
-    memory_region_transaction_begin();
     for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
         VirtQueue *vq = &vdev->vq[n];
 
@@ -2639,7 +2635,6 @@ static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev)
         r = virtio_bus_set_host_notifier(qbus, n, false);
         assert(r >= 0);
     }
-    memory_region_transaction_commit();
 }
 
 void virtio_device_stop_ioeventfd(VirtIODevice *vdev)

include/qemu/event_notifier.h

@@ -26,7 +26,6 @@ struct EventNotifier {
     int rfd;
     int wfd;
 #endif
-    void (*cleanup)(EventNotifier *);
 };
 
 typedef void EventNotifierHandler(EventNotifier *);

util/event_notifier-posix.c

@@ -29,7 +29,6 @@ void event_notifier_init_fd(EventNotifier *e, int fd)
 {
     e->rfd = fd;
     e->wfd = fd;
-    e->cleanup = NULL;
 }
 #endif
 
@@ -66,7 +65,6 @@ int event_notifier_init(EventNotifier *e, int active)
         e->rfd = fds[0];
         e->wfd = fds[1];
     }
-    e->cleanup = NULL;
     if (active) {
         event_notifier_set(e);
     }
@@ -82,11 +80,10 @@ void event_notifier_cleanup(EventNotifier *e)
 {
     if (e->rfd != e->wfd) {
         close(e->rfd);
+        e->rfd = -1;
     }
     close(e->wfd);
-    e->rfd = -1;
     e->wfd = -1;
-    e->cleanup = NULL;
 }
 
 int event_notifier_get_fd(const EventNotifier *e)

util/event_notifier-win32.c

@@ -19,7 +19,6 @@ int event_notifier_init(EventNotifier *e, int active)
 {
     e->event = CreateEvent(NULL, TRUE, FALSE, NULL);
     assert(e->event);
-    e->cleanup = NULL;
     return 0;
 }
 
@@ -27,7 +26,6 @@ void event_notifier_cleanup(EventNotifier *e)
 {
     CloseHandle(e->event);
     e->event = NULL;
-    e->cleanup = NULL;
 }
 
 HANDLE event_notifier_get_handle(EventNotifier *e)