On Thu, Apr 10, 2025 at 04:42:06PM +0900, Akihiko Odaki wrote:
> virtio-net expects set_features() will be called when the feature set
> used by the guest changes to update the number of virtqueues. Call it
> during reset as reset clears all features and the queues added for
> VIRTIO_NET_F_MQ or VIRTIO_NET_F_RSS will need to be removed.
>
> Fixes: f9d6dbf0bf6e ("virtio-net: remove virtio queues if the guest doesn't
> support multiqueue")
> Buglink: https://issues.redhat.com/browse/RHEL-73842
> Cc: qemu-sta...@nongnu.org
> Signed-off-by: Akihiko Odaki <akihiko.od...@daynix.com>
The issue seems specific to virtio net: rset is reset,
it is distict from set features.
Why not just call the necessary functionality from virtio_net_reset?
> ---
> hw/virtio/virtio.c | 86
> +++++++++++++++++++++++++++---------------------------
> 1 file changed, 43 insertions(+), 43 deletions(-)
>
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 85110bce3744..033e87cdd3b9 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -2316,49 +2316,6 @@ void virtio_queue_enable(VirtIODevice *vdev, uint32_t
> queue_index)
> }
> }
>
> -void virtio_reset(void *opaque)
> -{
> - VirtIODevice *vdev = opaque;
> - VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
> - int i;
> -
> - virtio_set_status(vdev, 0);
> - if (current_cpu) {
> - /* Guest initiated reset */
> - vdev->device_endian = virtio_current_cpu_endian();
> - } else {
> - /* System reset */
> - vdev->device_endian = virtio_default_endian();
> - }
> -
> - if (k->get_vhost) {
> - struct vhost_dev *hdev = k->get_vhost(vdev);
> - /* Only reset when vhost back-end is connected */
> - if (hdev && hdev->vhost_ops) {
> - vhost_reset_device(hdev);
> - }
> - }
> -
> - if (k->reset) {
> - k->reset(vdev);
> - }
> -
> - vdev->start_on_kick = false;
> - vdev->started = false;
> - vdev->broken = false;
> - vdev->guest_features = 0;
> - vdev->queue_sel = 0;
> - vdev->status = 0;
> - vdev->disabled = false;
> - qatomic_set(&vdev->isr, 0);
> - vdev->config_vector = VIRTIO_NO_VECTOR;
> - virtio_notify_vector(vdev, vdev->config_vector);
> -
> - for(i = 0; i < VIRTIO_QUEUE_MAX; i++) {
> - __virtio_queue_reset(vdev, i);
> - }
> -}
> -
> void virtio_queue_set_addr(VirtIODevice *vdev, int n, hwaddr addr)
> {
> if (!vdev->vq[n].vring.num) {
> @@ -3169,6 +3126,49 @@ int virtio_set_features(VirtIODevice *vdev, uint64_t
> val)
> return ret;
> }
>
> +void virtio_reset(void *opaque)
> +{
> + VirtIODevice *vdev = opaque;
> + VirtioDeviceClass *k = VIRTIO_DEVICE_GET_CLASS(vdev);
> + int i;
> +
> + virtio_set_status(vdev, 0);
> + if (current_cpu) {
> + /* Guest initiated reset */
> + vdev->device_endian = virtio_current_cpu_endian();
> + } else {
> + /* System reset */
> + vdev->device_endian = virtio_default_endian();
> + }
> +
> + if (k->get_vhost) {
> + struct vhost_dev *hdev = k->get_vhost(vdev);
> + /* Only reset when vhost back-end is connected */
> + if (hdev && hdev->vhost_ops) {
> + vhost_reset_device(hdev);
> + }
> + }
> +
> + if (k->reset) {
> + k->reset(vdev);
> + }
> +
> + vdev->start_on_kick = false;
> + vdev->started = false;
> + vdev->broken = false;
> + virtio_set_features_nocheck(vdev, 0);
> + vdev->queue_sel = 0;
> + vdev->status = 0;
> + vdev->disabled = false;
> + qatomic_set(&vdev->isr, 0);
> + vdev->config_vector = VIRTIO_NO_VECTOR;
> + virtio_notify_vector(vdev, vdev->config_vector);
> +
> + for (i = 0; i < VIRTIO_QUEUE_MAX; i++) {
> + __virtio_queue_reset(vdev, i);
> + }
> +}
> +
> static void virtio_device_check_notification_compatibility(VirtIODevice
> *vdev,
> Error **errp)
> {
>
> ---
> base-commit: 825b96dbcee23d134b691fc75618b59c5f53da32
> change-id: 20250406-reset-5ed5248ee3c1
>
> Best regards,
> --
> Akihiko Odaki <akihiko.od...@daynix.com>
