[PATCHv2] qemu-kvm: fix crash on reboot with vhost-net

Commit Message

Michael S. Tsirkin April 28, 2010, 9:27 a.m. UTC

None

Patch

diff --git a/hw/msix.c b/hw/msix.c
index 3ec8805..8f9a621 100644
--- a/hw/msix.c
+++ b/hw/msix.c
@@ -609,14 +609,44 @@  void msix_unuse_all_vectors(PCIDevice *dev)
 
 int msix_set_mask_notifier(PCIDevice *dev, unsigned vector, void *opaque)
 {
+    int r;
+    if (vector >= dev->msix_entries_nr || !dev->msix_entry_used[vector])
+        return 0;
+
+    assert(dev->msix_mask_notifier);
+    assert(opaque);
+    assert(!dev->msix_mask_notifier_opaque[vector]);
+
+    if (msix_is_masked(dev, vector)) {
+        return 0;
+    }
+    r = dev->msix_mask_notifier(dev, vector, opaque,
+                                msix_is_masked(dev, vector));
+    if (r < 0) {
+        return r;
+    }
+    dev->msix_mask_notifier_opaque[vector] = opaque;
+    return r;
+}
+
+int msix_unset_mask_notifier(PCIDevice *dev, unsigned vector)
+{
     int r = 0;
     if (vector >= dev->msix_entries_nr || !dev->msix_entry_used[vector])
         return 0;
 
-    if (dev->msix_mask_notifier)
-        r = dev->msix_mask_notifier(dev, vector, opaque,
-                                    msix_is_masked(dev, vector));
-    if (r >= 0)
-        dev->msix_mask_notifier_opaque[vector] = opaque;
+    assert(dev->msix_mask_notifier);
+    assert(dev->msix_mask_notifier_opaque[vector]);
+
+    if (msix_is_masked(dev, vector)) {
+        return 0;
+    }
+    r = dev->msix_mask_notifier(dev, vector,
+                                dev->msix_mask_notifier_opaque[vector],
+                                msix_is_masked(dev, vector));
+    if (r < 0) {
+        return r;
+    }
+    dev->msix_mask_notifier_opaque[vector] = NULL;
     return r;
 }
diff --git a/hw/msix.h b/hw/msix.h
index f167231..6b21ffb 100644
--- a/hw/msix.h
+++ b/hw/msix.h
@@ -34,4 +34,5 @@  void msix_reset(PCIDevice *dev);
 extern int msix_supported;
 
 int msix_set_mask_notifier(PCIDevice *dev, unsigned vector, void *opaque);
+int msix_unset_mask_notifier(PCIDevice *dev, unsigned vector);
 #endif
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 99a588c..c4bc633 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -462,10 +462,13 @@  static int virtio_pci_set_guest_notifier(void *opaque, int n, bool assign)
         msix_set_mask_notifier(&proxy->pci_dev,
                                virtio_queue_vector(proxy->vdev, n), vq);
     } else {
-        msix_set_mask_notifier(&proxy->pci_dev,
-                               virtio_queue_vector(proxy->vdev, n), NULL);
+        msix_unset_mask_notifier(&proxy->pci_dev,
+				 virtio_queue_vector(proxy->vdev, n));
         qemu_set_fd_handler(event_notifier_get_fd(notifier),
                             NULL, NULL, NULL);
+        /* Test and clear notifier before closing it,
+         * in case poll callback didn't have time to run. */
+        virtio_pci_guest_notifier_read(vq);
         event_notifier_cleanup(notifier);
     }