[Qemu-devel] [PATCH 0/3] virtio: host notifier API cleanup

[Qemu-devel] [PATCH 0/3] virtio: host notifier API cleanup

[Michael S. Tsirkin]

This refactors the code for enabling/disabling host notifiers.
Not useful by itself, but seems to be needed for other projects.
So I'm not merging this yet, will be included with other
patches.
Posting now for early review.

Michael S. Tsirkin (3):
  virtio: interface to enable/disable host notifiers
  dataplane/virtio-blk.c: new API to enable notifiers
  dataplane/virtio-scsi: new API to enable host notifiers

 include/hw/virtio/virtio.h      |  4 ++-
 hw/block/dataplane/virtio-blk.c |  6 ++---
 hw/scsi/virtio-scsi-dataplane.c | 14 +++-------
 hw/virtio/vhost.c               | 45 ++-----------------------------
 hw/virtio/virtio.c              | 59 ++++++++++++++++++++++++++++++++++++++++-
 5 files changed, 70 insertions(+), 58 deletions(-)

-- 
MST

[Qemu-devel] [PATCH 1/3] virtio: interface to enable/disable host notifiers

[Michael S. Tsirkin]

generalize and move these from vhost to virtio.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/hw/virtio/virtio.h |  3 +++
 hw/virtio/vhost.c          | 45 ++--------------------------------------
 hw/virtio/virtio.c         | 51 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 56 insertions(+), 43 deletions(-)

diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index d95f8b6..e1cff22 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -219,6 +219,9 @@ void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign,
 void virtio_queue_notify_vq(VirtQueue *vq);
 void virtio_irq(VirtQueue *vq);
 
+int virtio_enable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs);
+void virtio_disable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs);
+
 static inline void virtio_add_feature(uint32_t *features, unsigned int fbit)
 {
     assert(fbit < 32);
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 5a12861..8dd2f59 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -918,36 +918,7 @@ bool vhost_dev_query(struct vhost_dev *hdev, VirtIODevice *vdev)
  */
 int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
 {
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    VirtioBusState *vbus = VIRTIO_BUS(qbus);
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
-    int i, r;
-    if (!k->set_host_notifier) {
-        fprintf(stderr, "binding does not support host notifiers\n");
-        r = -ENOSYS;
-        goto fail;
-    }
-
-    for (i = 0; i < hdev->nvqs; ++i) {
-        r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, true);
-        if (r < 0) {
-            fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r);
-            goto fail_vq;
-        }
-    }
-
-    return 0;
-fail_vq:
-    while (--i >= 0) {
-        r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false);
-        if (r < 0) {
-            fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
-            fflush(stderr);
-        }
-        assert (r >= 0);
-    }
-fail:
-    return r;
+    return virtio_enable_host_notifiers(vdev, hdev->vq_index, hdev->nvqs);
 }
 
 /* Stop processing guest IO notifications in vhost.
@@ -957,19 +928,7 @@ fail:
  */
 void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
 {
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
-    VirtioBusState *vbus = VIRTIO_BUS(qbus);
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
-    int i, r;
-
-    for (i = 0; i < hdev->nvqs; ++i) {
-        r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false);
-        if (r < 0) {
-            fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);
-            fflush(stderr);
-        }
-        assert (r >= 0);
-    }
+    virtio_disable_host_notifiers(vdev, hdev->vq_index, hdev->nvqs);
 }
 
 /* Test and clear event pending status.
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 17c1260..e7ee069 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -1283,6 +1283,57 @@ void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name)
     vdev->bus_name = g_strdup(bus_name);
 }
 
+int virtio_enable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs)
+{
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+    VirtioBusState *vbus = VIRTIO_BUS(qbus);
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
+    int i, r;
+    if (!k->set_host_notifier) {
+        fprintf(stderr, "binding does not support host notifiers\n");
+        r = -ENOSYS;
+        goto fail;
+    }
+
+    for (i = 0; i < nvqs; ++i) {
+        r = k->set_host_notifier(qbus->parent, startvq + i, true);
+        if (r < 0) {
+            fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r);
+            goto fail_vq;
+        }
+    }
+
+    return 0;
+fail_vq:
+    while (--i >= 0) {
+        r = k->set_host_notifier(qbus->parent, startvq + i, false);
+        if (r < 0) {
+            fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
+            fflush(stderr);
+        }
+        assert (r >= 0);
+    }
+fail:
+    return r;
+}
+
+void virtio_disable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs)
+{
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+    VirtioBusState *vbus = VIRTIO_BUS(qbus);
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
+    int i, r;
+
+    for (i = 0; i < nvqs; ++i) {
+        r = k->set_host_notifier(qbus->parent, startvq + i, false);
+        if (r < 0) {
+            fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);
+            fflush(stderr);
+        }
+        assert (r >= 0);
+    }
+}
+
 static void virtio_device_realize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
-- 
MST

[Qemu-devel] [PATCH 2/3] dataplane/virtio-blk.c: new API to enable notifiers

[Michael S. Tsirkin]

Switch to new API, no functional changes.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/block/dataplane/virtio-blk.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index cd41478..c9ac70e 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -263,7 +263,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
     s->guest_notifier = virtio_queue_get_guest_notifier(vq);
 
     /* Set up virtqueue notify */
-    r = k->set_host_notifier(qbus->parent, 0, true);
+    r = virtio_enable_host_notifiers(s->vdev, 0, 1);
     if (r != 0) {
         fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
         goto fail_host_notifier;
@@ -289,7 +289,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
     return;
 
   fail_host_notifier:
-    k->set_guest_notifiers(qbus->parent, 1, false);
+    virtio_disable_host_notifiers(s->vdev, 0, 1);
   fail_guest_notifiers:
     vring_teardown(&s->vring, s->vdev, 0);
     s->disabled = true;
@@ -332,7 +332,7 @@ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
      */
     vring_teardown(&s->vring, s->vdev, 0);
 
-    k->set_host_notifier(qbus->parent, 0, false);
+    virtio_disable_host_notifiers(s->vdev, 0, 1);
 
     /* Clean up guest notifier (irq) */
     k->set_guest_notifiers(qbus->parent, 1, false);
-- 
MST

[Qemu-devel] [PATCH 3/3] dataplane/virtio-scsi: new API to enable host notifiers

[Michael S. Tsirkin]

Switch to new API.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/hw/virtio/virtio.h      |  1 -
 hw/scsi/virtio-scsi-dataplane.c | 14 ++++----------
 hw/virtio/virtio.c              |  8 +++++++-
 3 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index e1cff22..7e70193 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -217,7 +217,6 @@ EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
 void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign,
                                                bool set_handler);
 void virtio_queue_notify_vq(VirtQueue *vq);
-void virtio_irq(VirtQueue *vq);
 
 int virtio_enable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs);
 void virtio_disable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs);
diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c
index 5575648..965ccb8 100644
--- a/hw/scsi/virtio-scsi-dataplane.c
+++ b/hw/scsi/virtio-scsi-dataplane.c
@@ -43,13 +43,11 @@ static VirtIOSCSIVring *virtio_scsi_vring_init(VirtIOSCSI *s,
                                                EventNotifierHandler *handler,
                                                int n)
 {
-    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
-    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     VirtIOSCSIVring *r;
     int rc;
 
     /* Set up virtqueue notify */
-    rc = k->set_host_notifier(qbus->parent, n, true);
+    rc = virtio_enable_host_notifiers(VIRTIO_DEVICE(s), n, 1);
     if (rc != 0) {
         fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n",
                 rc);
@@ -72,7 +70,7 @@ static VirtIOSCSIVring *virtio_scsi_vring_init(VirtIOSCSI *s,
 
 fail_vring:
     aio_set_event_notifier(s->ctx, &r->host_notifier, NULL);
-    k->set_host_notifier(qbus->parent, n, false);
+    virtio_disable_host_notifiers(VIRTIO_DEVICE(s), n, 1);
     g_slice_free(VirtIOSCSIVring, r);
     return NULL;
 }
@@ -261,9 +259,7 @@ fail_vrings:
     virtio_scsi_clear_aio(s);
     aio_context_release(s->ctx);
     virtio_scsi_vring_teardown(s);
-    for (i = 0; i < vs->conf.num_queues + 2; i++) {
-        k->set_host_notifier(qbus->parent, i, false);
-    }
+    virtio_disable_host_notifiers(VIRTIO_DEVICE(s), 0, vs->conf.num_queues + 2);
     k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
 fail_guest_notifiers:
     s->dataplane_starting = false;
@@ -305,9 +301,7 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s)
      */
     virtio_scsi_vring_teardown(s);
 
-    for (i = 0; i < vs->conf.num_queues + 2; i++) {
-        k->set_host_notifier(qbus->parent, i, false);
-    }
+    virtio_disable_host_notifiers(VIRTIO_DEVICE(s), 0, vs->conf.num_queues + 2);
 
     /* Clean up guest notifier (irq) */
     k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index e7ee069..60d10cd 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -84,6 +84,9 @@ struct VirtQueue
 
     int inuse;
 
+    /* Host notifier enabled? */
+    bool host_notifier_enabled;
+
     uint16_t vector;
     void (*handle_output)(VirtIODevice *vdev, VirtQueue *vq);
     VirtIODevice *vdev;
@@ -813,7 +816,7 @@ void virtio_del_queue(VirtIODevice *vdev, int n)
     vdev->vq[n].vring.num = 0;
 }
 
-void virtio_irq(VirtQueue *vq)
+static void virtio_irq(VirtQueue *vq)
 {
     trace_virtio_irq(vq);
     vq->vdev->isr |= 0x01;
@@ -1301,11 +1304,13 @@ int virtio_enable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs)
             fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r);
             goto fail_vq;
         }
+        vdev->vq[startvq + i].host_notifier_enabled = true;
     }
 
     return 0;
 fail_vq:
     while (--i >= 0) {
+        vdev->vq[startvq + i].host_notifier_enabled = false;
         r = k->set_host_notifier(qbus->parent, startvq + i, false);
         if (r < 0) {
             fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
@@ -1325,6 +1330,7 @@ void virtio_disable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs)
     int i, r;
 
     for (i = 0; i < nvqs; ++i) {
+        vdev->vq[startvq + i].host_notifier_enabled = false;
         r = k->set_host_notifier(qbus->parent, startvq + i, false);
         if (r < 0) {
             fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);
-- 
MST

Re: [Qemu-devel] [PATCH 1/3] virtio: interface to enable/disable host notifiers

[Cornelia Huck]

On Tue, 7 Apr 2015 12:45:56 +0200
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> generalize and move these from vhost to virtio.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  include/hw/virtio/virtio.h |  3 +++
>  hw/virtio/vhost.c          | 45 ++--------------------------------------
>  hw/virtio/virtio.c         | 51 ++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 56 insertions(+), 43 deletions(-)
> 

> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 17c1260..e7ee069 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -1283,6 +1283,57 @@ void virtio_device_set_child_bus_name(VirtIODevice *vdev, char *bus_name)
>      vdev->bus_name = g_strdup(bus_name);
>  }
> 
> +int virtio_enable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs)

I realize that you just move the function, but would it make sense to
verify that startvq + nvqs is actually still a valid queue?

> +{
> +    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
> +    VirtioBusState *vbus = VIRTIO_BUS(qbus);
> +    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
> +    int i, r;
> +    if (!k->set_host_notifier) {
> +        fprintf(stderr, "binding does not support host notifiers\n");
> +        r = -ENOSYS;
> +        goto fail;
> +    }
> +
> +    for (i = 0; i < nvqs; ++i) {
> +        r = k->set_host_notifier(qbus->parent, startvq + i, true);
> +        if (r < 0) {
> +            fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r);

I think you'll want to get rid of the vhost in the message here. And
the number of the failing virtqueue is startvq+i, no?

Also: would it make sense to convert this to the error reporting
infrastructure?

> +            goto fail_vq;
> +        }
> +    }
> +
> +    return 0;
> +fail_vq:
> +    while (--i >= 0) {
> +        r = k->set_host_notifier(qbus->parent, startvq + i, false);
> +        if (r < 0) {
> +            fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
> +            fflush(stderr);
> +        }
> +        assert (r >= 0);
> +    }
> +fail:
> +    return r;
> +}
> +
> +void virtio_disable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs)
> +{
> +    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
> +    VirtioBusState *vbus = VIRTIO_BUS(qbus);
> +    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
> +    int i, r;
> +
> +    for (i = 0; i < nvqs; ++i) {
> +        r = k->set_host_notifier(qbus->parent, startvq + i, false);

Should a generic function maybe check for ->set_host_notifier and bail
out early if it doesn't exist? Probably depends on how the callers want
to handle non-existence of host notifiers.

> +        if (r < 0) {
> +            fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);
> +            fflush(stderr);
> +        }
> +        assert (r >= 0);
> +    }
> +}
> +
>  static void virtio_device_realize(DeviceState *dev, Error **errp)
>  {
>      VirtIODevice *vdev = VIRTIO_DEVICE(dev);

Re: [Qemu-devel] [PATCH 2/3] dataplane/virtio-blk.c: new API to enable notifiers

[Cornelia Huck]

On Tue, 7 Apr 2015 12:45:58 +0200
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> Switch to new API, no functional changes.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  hw/block/dataplane/virtio-blk.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
> index cd41478..c9ac70e 100644
> --- a/hw/block/dataplane/virtio-blk.c
> +++ b/hw/block/dataplane/virtio-blk.c
> @@ -263,7 +263,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
>      s->guest_notifier = virtio_queue_get_guest_notifier(vq);
> 
>      /* Set up virtqueue notify */
> -    r = k->set_host_notifier(qbus->parent, 0, true);
> +    r = virtio_enable_host_notifiers(s->vdev, 0, 1);
>      if (r != 0) {
>          fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
>          goto fail_host_notifier;
> @@ -289,7 +289,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
>      return;
> 
>    fail_host_notifier:
> -    k->set_guest_notifiers(qbus->parent, 1, false);
> +    virtio_disable_host_notifiers(s->vdev, 0, 1);

This one is supposed to disable the guest notifier, not the host
notifier.

>    fail_guest_notifiers:
>      vring_teardown(&s->vring, s->vdev, 0);
>      s->disabled = true;
> @@ -332,7 +332,7 @@ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
>       */
>      vring_teardown(&s->vring, s->vdev, 0);
> 
> -    k->set_host_notifier(qbus->parent, 0, false);
> +    virtio_disable_host_notifiers(s->vdev, 0, 1);
> 
>      /* Clean up guest notifier (irq) */
>      k->set_guest_notifiers(qbus->parent, 1, false);

Re: [Qemu-devel] [PATCH 3/3] dataplane/virtio-scsi: new API to enable host notifiers

[Cornelia Huck]

On Tue, 7 Apr 2015 12:46:01 +0200
"Michael S. Tsirkin" <mst@redhat.com> wrote:

> Switch to new API.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  include/hw/virtio/virtio.h      |  1 -
>  hw/scsi/virtio-scsi-dataplane.c | 14 ++++----------
>  hw/virtio/virtio.c              |  8 +++++++-
>  3 files changed, 11 insertions(+), 12 deletions(-)
> 
> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> index e1cff22..7e70193 100644
> --- a/include/hw/virtio/virtio.h
> +++ b/include/hw/virtio/virtio.h
> @@ -217,7 +217,6 @@ EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
>  void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign,
>                                                 bool set_handler);
>  void virtio_queue_notify_vq(VirtQueue *vq);
> -void virtio_irq(VirtQueue *vq);

Unrelated cleanup?

> 
>  int virtio_enable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs);
>  void virtio_disable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs);

(...)

> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index e7ee069..60d10cd 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -84,6 +84,9 @@ struct VirtQueue
> 
>      int inuse;
> 
> +    /* Host notifier enabled? */
> +    bool host_notifier_enabled;

This looks to be write-only. Have you maybe mixed in some unrelated
changes?

> +
>      uint16_t vector;
>      void (*handle_output)(VirtIODevice *vdev, VirtQueue *vq);
>      VirtIODevice *vdev;
> @@ -813,7 +816,7 @@ void virtio_del_queue(VirtIODevice *vdev, int n)
>      vdev->vq[n].vring.num = 0;
>  }
> 
> -void virtio_irq(VirtQueue *vq)
> +static void virtio_irq(VirtQueue *vq)
>  {
>      trace_virtio_irq(vq);
>      vq->vdev->isr |= 0x01;
> @@ -1301,11 +1304,13 @@ int virtio_enable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs)
>              fprintf(stderr, "vhost VQ %d notifier binding failed: %d\n", i, -r);
>              goto fail_vq;
>          }
> +        vdev->vq[startvq + i].host_notifier_enabled = true;
>      }
> 
>      return 0;
>  fail_vq:
>      while (--i >= 0) {
> +        vdev->vq[startvq + i].host_notifier_enabled = false;
>          r = k->set_host_notifier(qbus->parent, startvq + i, false);
>          if (r < 0) {
>              fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
> @@ -1325,6 +1330,7 @@ void virtio_disable_host_notifiers(VirtIODevice *vdev, int startvq, int nvqs)
>      int i, r;
> 
>      for (i = 0; i < nvqs; ++i) {
> +        vdev->vq[startvq + i].host_notifier_enabled = false;
>          r = k->set_host_notifier(qbus->parent, startvq + i, false);
>          if (r < 0) {
>              fprintf(stderr, "vhost VQ %d notifier cleanup failed: %d\n", i, -r);