@@ -173,18 +173,46 @@ static int virtio_pci_set_host_notifier_internal(VirtIOPCIProxy *proxy,
__func__, r);
return r;
}
- virtio_queue_set_host_notifier_fd_handler(vq, true);
memory_region_add_eventfd(&proxy->bar, VIRTIO_PCI_QUEUE_NOTIFY, 2,
true, n, notifier);
} else {
memory_region_del_eventfd(&proxy->bar, VIRTIO_PCI_QUEUE_NOTIFY, 2,
true, n, notifier);
- virtio_queue_set_host_notifier_fd_handler(vq, false);
+ /* Handle the race condition where the guest kicked and we deassigned
+ * before we got around to handling the kick.
+ */
+ if (event_notifier_test_and_clear(notifier)) {
+ virtio_queue_notify_vq(vq);
+ }
+
event_notifier_cleanup(notifier);
}
return r;
}
+static void virtio_pci_host_notifier_read(void *opaque)
+{
+ VirtQueue *vq = opaque;
+ EventNotifier *n = virtio_queue_get_host_notifier(vq);
+ if (event_notifier_test_and_clear(n)) {
+ virtio_queue_notify_vq(vq);
+ }
+}
+
+static void virtio_pci_set_host_notifier_fd_handler(VirtIOPCIProxy *proxy,
+ int n, bool assign)
+{
+ VirtQueue *vq = virtio_get_queue(proxy->vdev, n);
+ EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
+ if (assign) {
+ qemu_set_fd_handler(event_notifier_get_fd(notifier),
+ virtio_pci_host_notifier_read, NULL, vq);
+ } else {
+ qemu_set_fd_handler(event_notifier_get_fd(notifier),
+ NULL, NULL, NULL);
+ }
+}
+
static void virtio_pci_start_ioeventfd(VirtIOPCIProxy *proxy)
{
int n, r;
@@ -204,6 +232,8 @@ static void virtio_pci_start_ioeventfd(VirtIOPCIProxy *proxy)
if (r < 0) {
goto assign_error;
}
+
+ virtio_pci_set_host_notifier_fd_handler(proxy, n, true);
}
proxy->ioeventfd_started = true;
return;
@@ -214,6 +244,7 @@ assign_error:
continue;
}
+ virtio_pci_set_host_notifier_fd_handler(proxy, n, false);
r = virtio_pci_set_host_notifier_internal(proxy, n, false);
assert(r >= 0);
}
@@ -235,6 +266,7 @@ static void virtio_pci_stop_ioeventfd(VirtIOPCIProxy *proxy)
continue;
}
+ virtio_pci_set_host_notifier_fd_handler(proxy, n, false);
r = virtio_pci_set_host_notifier_internal(proxy, n, false);
assert(r >= 0);
}
@@ -1012,28 +1012,6 @@ EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq)
{
return &vq->guest_notifier;
}
-
-static void virtio_queue_host_notifier_read(EventNotifier *n)
-{
- VirtQueue *vq = container_of(n, VirtQueue, host_notifier);
- if (event_notifier_test_and_clear(n)) {
- virtio_queue_notify_vq(vq);
- }
-}
-
-void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign)
-{
- if (assign) {
- event_notifier_set_handler(&vq->host_notifier,
- virtio_queue_host_notifier_read);
- } else {
- event_notifier_set_handler(&vq->host_notifier, NULL);
- /* Test and clear notifier before after disabling event,
- * in case poll callback didn't have time to run. */
- virtio_queue_host_notifier_read(&vq->host_notifier);
- }
-}
-
EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq)
{
return &vq->host_notifier;
@@ -233,7 +233,6 @@ EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
bool with_irqfd);
EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
-void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign);
void virtio_queue_notify_vq(VirtQueue *vq);
void virtio_irq(VirtQueue *vq);
#endif
This reverts commit b1f416aa8d870fab71030abc9401cfc77b948e8e. The above commit breaks vhost_net because it always registers the virtio_pci_host_notifier_read() handler function on the ioeventfd, even when vhost_net.ko is using the ioeventfd. The result is both QEMU and vhost_net.ko polling on the same eventfd and the virtio_net.ko guest driver seeing inconsistent results: # ifconfig eth0 192.168.0.1 netmask 255.255.255.0 virtio_net virtio0: output:id 0 is not a head! Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> --- hw/virtio-pci.c | 36 ++++++++++++++++++++++++++++++++++-- hw/virtio.c | 22 ---------------------- hw/virtio.h | 1 - 3 files changed, 34 insertions(+), 25 deletions(-)