The function vhost.c:vhost_dev_stop calls vhost operation vhost_dev_start(false). In the case of vdpa it totally reset and wipes the device, making the fetching of the vring base (virtqueue state) totally useless.
The kernel backend does not use vhost_dev_start vhost op callback, but vhost-user do. A patch to make vhost_user_dev_start more similar to vdpa is desirable, but it can be added on top. Signed-off-by: Eugenio Pérez <epere...@redhat.com> --- include/hw/virtio/vhost-backend.h | 4 ++++ hw/virtio/vhost-vdpa.c | 22 ++++++++++++++++------ hw/virtio/vhost.c | 3 +++ 3 files changed, 23 insertions(+), 6 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 cbbe92ffe8..26e38a6aab 100644 --- a/hw/virtio/vhost-vdpa.c +++ b/hw/virtio/vhost-vdpa.c @@ -1152,14 +1152,23 @@ 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, @@ -1346,4 +1355,5 @@ 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, }; 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