[Qemu-devel] [PATCH 2/6] virtio-bus: have callers tolerate new host notifier api

[Cornelia Huck <cornelia.huck@de.ibm.com>]

Have vhost and dataplane use the new api for transports that
have been converted.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 hw/block/dataplane/virtio-blk.c | 14 +++++++++++---
 hw/scsi/virtio-scsi-dataplane.c | 20 +++++++++++++++-----
 hw/virtio/vhost.c               | 20 ++++++++++++++++----
 3 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 36f3d2b..9ca41d7 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -132,7 +132,8 @@ void virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
     }
 
     /* Don't try if transport does not support notifiers. */
-    if (!k->set_guest_notifiers || !k->set_host_notifier) {
+    if (!k->set_guest_notifiers ||
+        (!k->set_host_notifier && !k->ioeventfd_started)) {
         error_setg(errp,
                    "device is incompatible with dataplane "
                    "(transport does not support notifiers)");
@@ -209,7 +210,10 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
     s->guest_notifier = virtio_queue_get_guest_notifier(s->vq);
 
     /* Set up virtqueue notify */
-    r = k->set_host_notifier(qbus->parent, 0, true);
+    r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), 0, true);
+    if (r == -ENOSYS) {
+        r = k->set_host_notifier(qbus->parent, 0, true);
+    }
     if (r != 0) {
         fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
         goto fail_host_notifier;
@@ -244,6 +248,7 @@ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
+    int r;
 
     if (!vblk->dataplane_started || s->stopping) {
         return;
@@ -268,7 +273,10 @@ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
 
     aio_context_release(s->ctx);
 
-    k->set_host_notifier(qbus->parent, 0, false);
+    r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), 0, false);
+    if (r == -ENOSYS) {
+        k->set_host_notifier(qbus->parent, 0, false);
+    }
 
     /* Clean up guest notifier (irq) */
     k->set_guest_notifiers(qbus->parent, 1, false);
diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c
index 367e476..88c3abd 100644
--- a/hw/scsi/virtio-scsi-dataplane.c
+++ b/hw/scsi/virtio-scsi-dataplane.c
@@ -32,7 +32,8 @@ void virtio_scsi_set_iothread(VirtIOSCSI *s, IOThread *iothread)
     s->ctx = iothread_get_aio_context(vs->conf.iothread);
 
     /* Don't try if transport does not support notifiers. */
-    if (!k->set_guest_notifiers || !k->set_host_notifier) {
+    if (!k->set_guest_notifiers ||
+        (!k->set_host_notifier && !k->ioeventfd_started)) {
         fprintf(stderr, "virtio-scsi: Failed to set iothread "
                    "(transport does not support notifiers)");
         exit(1);
@@ -46,7 +47,10 @@ static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n)
     int rc;
 
     /* Set up virtqueue notify */
-    rc = k->set_host_notifier(qbus->parent, n, true);
+    rc = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), n, true);
+    if (rc == -ENOSYS) {
+        rc = k->set_host_notifier(qbus->parent, n, true);
+    }
     if (rc != 0) {
         fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n",
                 rc);
@@ -129,7 +133,10 @@ fail_vrings:
     virtio_scsi_clear_aio(s);
     aio_context_release(s->ctx);
     for (i = 0; i < vs->conf.num_queues + 2; i++) {
-        k->set_host_notifier(qbus->parent, i, false);
+        rc = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
+        if (rc == -ENOSYS) {
+            k->set_host_notifier(qbus->parent, i, false);
+        }
     }
     k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
 fail_guest_notifiers:
@@ -144,7 +151,7 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s)
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
-    int i;
+    int i, rc;
 
     if (!s->dataplane_started || s->dataplane_stopping) {
         return;
@@ -168,7 +175,10 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s)
     aio_context_release(s->ctx);
 
     for (i = 0; i < vs->conf.num_queues + 2; i++) {
-        k->set_host_notifier(qbus->parent, i, false);
+        rc = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), i, false);
+        if (rc == -ENOSYS) {
+            k->set_host_notifier(qbus->parent, i, false);
+        }
     }
 
     /* Clean up guest notifier (irq) */
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 392d848..4b8c151 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1113,14 +1113,18 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
     VirtioBusState *vbus = VIRTIO_BUS(qbus);
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
     int i, r, e;
-    if (!k->set_host_notifier) {
+    if (!k->set_host_notifier || !k->ioeventfd_started) {
         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);
+        r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i,
+                                         true);
+        if (r == -ENOSYS) {
+            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;
@@ -1130,7 +1134,11 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
     return 0;
 fail_vq:
     while (--i >= 0) {
-        e = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false);
+        e = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i,
+                                         false);
+        if (e == -ENOSYS) {
+            e = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false);
+        }
         if (e < 0) {
             fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r);
             fflush(stderr);
@@ -1154,7 +1162,11 @@ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev)
     int i, r;
 
     for (i = 0; i < hdev->nvqs; ++i) {
-        r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false);
+        r = virtio_bus_set_host_notifier(VIRTIO_BUS(qbus), hdev->vq_index + i,
+                                         false);
+        if (r == -ENOSYS) {
+            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);
-- 
2.6.5