On Fri, Jan 13, 2023 at 1:24 AM Eugenio Pérez <epere...@redhat.com> wrote: > > At this moment it is only possible to migrate to a vdpa device running > with x-svq=on. As a protective measure, the rewind of the inflight > descriptors was done at the destination. That way if the source sent a > virtqueue with inuse descriptors they are always discarded. > > Since this series allows to migrate also to passthrough devices with no > SVQ, the right thing to do is to rewind at the source so base of vrings > are correct. > > Support for inflight descriptors may be added in the future. > > Signed-off-by: Eugenio Pérez <epere...@redhat.com> > --- > include/hw/virtio/vhost-backend.h | 4 +++ > hw/virtio/vhost-vdpa.c | 46 +++++++++++++++++++------------ > hw/virtio/vhost.c | 3 ++ > 3 files changed, 36 insertions(+), 17 deletions(-) > > diff --git a/include/hw/virtio/vhost-backend.h > b/include/hw/virtio/vhost-backend.h > index c5ab49051e..ec3fbae58d 100644 > --- a/include/hw/virtio/vhost-backend.h > +++ b/include/hw/virtio/vhost-backend.h > @@ -130,6 +130,9 @@ typedef bool (*vhost_force_iommu_op)(struct vhost_dev > *dev); > > typedef int (*vhost_set_config_call_op)(struct vhost_dev *dev, > int fd); > + > +typedef void (*vhost_reset_status_op)(struct vhost_dev *dev); > + > typedef struct VhostOps { > VhostBackendType backend_type; > vhost_backend_init vhost_backend_init; > @@ -177,6 +180,7 @@ typedef struct VhostOps { > vhost_get_device_id_op vhost_get_device_id; > vhost_force_iommu_op vhost_force_iommu; > vhost_set_config_call_op vhost_set_config_call; > + vhost_reset_status_op vhost_reset_status; > } VhostOps; > > int vhost_backend_update_device_iotlb(struct vhost_dev *dev, > diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c > index 542e003101..28a52ddc78 100644 > --- a/hw/virtio/vhost-vdpa.c > +++ b/hw/virtio/vhost-vdpa.c > @@ -1132,14 +1132,23 @@ static int vhost_vdpa_dev_start(struct vhost_dev > *dev, bool started) > if (started) { > memory_listener_register(&v->listener, &address_space_memory); > return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); > - } else { > - vhost_vdpa_reset_device(dev); > - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE | > - VIRTIO_CONFIG_S_DRIVER); > - memory_listener_unregister(&v->listener); > + } > > - return 0; > + return 0; > +} > + > +static void vhost_vdpa_reset_status(struct vhost_dev *dev) > +{ > + struct vhost_vdpa *v = dev->opaque; > + > + if (dev->vq_index + dev->nvqs != dev->vq_index_end) { > + return; > } > + > + vhost_vdpa_reset_device(dev); > + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE | > + VIRTIO_CONFIG_S_DRIVER); > + memory_listener_unregister(&v->listener); > } > > static int vhost_vdpa_set_log_base(struct vhost_dev *dev, uint64_t base, > @@ -1182,18 +1191,7 @@ static int vhost_vdpa_set_vring_base(struct vhost_dev > *dev, > struct vhost_vring_state *ring) > { > struct vhost_vdpa *v = dev->opaque; > - VirtQueue *vq = virtio_get_queue(dev->vdev, ring->index); > > - /* > - * vhost-vdpa devices does not support in-flight requests. Set all of > them > - * as available. > - * > - * TODO: This is ok for networking, but other kinds of devices might > - * have problems with these retransmissions. > - */ > - while (virtqueue_rewind(vq, 1)) { > - continue; > - } > if (v->shadow_vqs_enabled) { > /* > * Device vring base was set at device start. SVQ base is handled by > @@ -1212,6 +1210,19 @@ static int vhost_vdpa_get_vring_base(struct vhost_dev > *dev, > int ret; > > if (v->shadow_vqs_enabled) { > + VirtQueue *vq = virtio_get_queue(dev->vdev, ring->index); > + > + /* > + * vhost-vdpa devices does not support in-flight requests. Set all of > + * them as available. > + * > + * TODO: This is ok for networking, but other kinds of devices might > + * have problems with these retransmissions. > + */ > + while (virtqueue_rewind(vq, 1)) { > + continue; > + } > + > ring->num = virtio_queue_get_last_avail_idx(dev->vdev, ring->index); > return 0; > } > @@ -1326,4 +1337,5 @@ const VhostOps vdpa_ops = { > .vhost_vq_get_addr = vhost_vdpa_vq_get_addr, > .vhost_force_iommu = vhost_vdpa_force_iommu, > .vhost_set_config_call = vhost_vdpa_set_config_call, > + .vhost_reset_status = vhost_vdpa_reset_status,
Can we simply use the NetClient stop method here? Thanks > }; > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > index eb8c4c378c..a266396576 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -2049,6 +2049,9 @@ void vhost_dev_stop(struct vhost_dev *hdev, > VirtIODevice *vdev, bool vrings) > hdev->vqs + i, > hdev->vq_index + i); > } > + if (hdev->vhost_ops->vhost_reset_status) { > + hdev->vhost_ops->vhost_reset_status(hdev); > + } > > if (vhost_dev_has_iommu(hdev)) { > if (hdev->vhost_ops->vhost_set_iotlb_callback) { > -- > 2.31.1 >