On Tue, Oct 11, 2022 at 12:41:50PM +0200, Eugenio Pérez wrote:
> SVQ may run or not in a device depending on runtime conditions (for
> example, if the device can move CVQ to its own group or not).
>
> Allocate the resources unconditionally, and decide later if to use them
> or not.
>
> Signed-off-by: Eugenio Pérez <eperezma@xxxxxxxxxx>
I applied this for now but I really dislike it that we are wasting
resources like this.
Can I just drop this patch from the series? It looks like things
will just work anyway ...
I know, when one works on a feature it seems like everyone should
enable it - but the reality is qemu already works quite well for
most users and it is our resposibility to first do no harm.
> ---
> hw/virtio/vhost-vdpa.c | 33 +++++++++++++++------------------
> 1 file changed, 15 insertions(+), 18 deletions(-)
>
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 7f0ff4df5b..d966966131 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -410,6 +410,21 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
> int r;
> bool ok;
>
> + shadow_vqs = g_ptr_array_new_full(hdev->nvqs, vhost_svq_free);
> + for (unsigned n = 0; n < hdev->nvqs; ++n) {
> + g_autoptr(VhostShadowVirtqueue) svq;
> +
> + svq = vhost_svq_new(v->iova_tree, v->shadow_vq_ops,
> + v->shadow_vq_ops_opaque);
> + if (unlikely(!svq)) {
> + error_setg(errp, "Cannot create svq %u", n);
> + return -1;
> + }
> + g_ptr_array_add(shadow_vqs, g_steal_pointer(&svq));
> + }
> +
> + v->shadow_vqs = g_steal_pointer(&shadow_vqs);
> +
> if (!v->shadow_vqs_enabled) {
> return 0;
> }
> @@ -426,20 +441,6 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
> return -1;
> }
>
> - shadow_vqs = g_ptr_array_new_full(hdev->nvqs, vhost_svq_free);
> - for (unsigned n = 0; n < hdev->nvqs; ++n) {
> - g_autoptr(VhostShadowVirtqueue) svq;
> -
> - svq = vhost_svq_new(v->iova_tree, v->shadow_vq_ops,
> - v->shadow_vq_ops_opaque);
> - if (unlikely(!svq)) {
> - error_setg(errp, "Cannot create svq %u", n);
> - return -1;
> - }
> - g_ptr_array_add(shadow_vqs, g_steal_pointer(&svq));
> - }
> -
> - v->shadow_vqs = g_steal_pointer(&shadow_vqs);
> return 0;
> }
>
> @@ -580,10 +581,6 @@ static void vhost_vdpa_svq_cleanup(struct vhost_dev *dev)
> struct vhost_vdpa *v = dev->opaque;
> size_t idx;
>
> - if (!v->shadow_vqs) {
> - return;
> - }
> -
> for (idx = 0; idx < v->shadow_vqs->len; ++idx) {
> vhost_svq_stop(g_ptr_array_index(v->shadow_vqs, idx));
> }
> --
> 2.31.1
