[PATCH v2 09/10] vdpa-dev: implement the set_status interface

["Longpeng(Mike)" via <qemu-devel@nongnu.org>]

From: Longpeng <longpeng2@huawei.com>

Implements the .set_status interface.

Signed-off-by: Longpeng <longpeng2@huawei.com>
---
 hw/virtio/vdpa-dev.c | 100 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 99 insertions(+), 1 deletion(-)

diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c
index 7bf07fef9b..99722c88a1 100644
--- a/hw/virtio/vdpa-dev.c
+++ b/hw/virtio/vdpa-dev.c
@@ -195,9 +195,107 @@ static uint64_t vhost_vdpa_device_get_features(VirtIODevice *vdev,
     return backend_features;
 }
 
+static int vhost_vdpa_device_start(VirtIODevice *vdev, Error **errp)
+{
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    int i, ret;
+
+    if (!k->set_guest_notifiers) {
+        error_setg(errp, "binding does not support guest notifiers");
+        return -ENOSYS;
+    }
+
+    ret = vhost_dev_enable_notifiers(&s->dev, vdev);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Error enabling host notifiers");
+        return ret;
+    }
+
+    ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Error binding guest notifier");
+        goto err_host_notifiers;
+    }
+
+    s->dev.acked_features = vdev->guest_features;
+
+    ret = vhost_dev_start(&s->dev, vdev);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Error starting vhost");
+        goto err_guest_notifiers;
+    }
+    s->started = true;
+
+    /*
+     * guest_notifier_mask/pending not used yet, so just unmask
+     * everything here. virtio-pci will do the right thing by
+     * enabling/disabling irqfd.
+     */
+    for (i = 0; i < s->dev.nvqs; i++) {
+        vhost_virtqueue_mask(&s->dev, vdev, i, false);
+    }
+
+    return ret;
+
+err_guest_notifiers:
+    k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
+err_host_notifiers:
+    vhost_dev_disable_notifiers(&s->dev, vdev);
+    return ret;
+}
+
+static void vhost_vdpa_device_stop(VirtIODevice *vdev)
+{
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    int ret;
+
+    if (!s->started) {
+        return;
+    }
+    s->started = false;
+
+    if (!k->set_guest_notifiers) {
+        return;
+    }
+
+    vhost_dev_stop(&s->dev, vdev);
+
+    ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
+    if (ret < 0) {
+        error_report("vhost guest notifier cleanup failed: %d", ret);
+        return;
+    }
+
+    vhost_dev_disable_notifiers(&s->dev, vdev);
+}
+
 static void vhost_vdpa_device_set_status(VirtIODevice *vdev, uint8_t status)
 {
-    return;
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
+    bool should_start = virtio_device_started(vdev, status);
+    Error *local_err = NULL;
+    int ret;
+
+    if (!vdev->vm_running) {
+        should_start = false;
+    }
+
+    if (s->started == should_start) {
+        return;
+    }
+
+    if (should_start) {
+        ret = vhost_vdpa_device_start(vdev, &local_err);
+        if (ret < 0) {
+            error_reportf_err(local_err, "vhost-vdpa-device: start failed: ");
+        }
+    } else {
+        vhost_vdpa_device_stop(vdev);
+    }
 }
 
 static Property vhost_vdpa_device_properties[] = {
-- 
2.23.0