Re: [PATCH v6 05/10] vdpa: move SVQ vring features check to net/

[Jason Wang]

在 2022/11/9 01:07, Eugenio Pérez 写道:
> The next patches will start control SVQ if possible. However, we don't
> know if that will be possible at qemu boot anymore.


If I was not wrong, there's no device specific feature that is checked 
in the function. So it should be general enough to be used by devices 
other than net. Then I don't see any advantage of doing this.

Thanks


> Since the moved checks will be already evaluated at net/ to know if it
> is ok to shadow CVQ, move them.
>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
>   hw/virtio/vhost-vdpa.c | 33 ++-------------------------------
>   net/vhost-vdpa.c       |  3 ++-
>   2 files changed, 4 insertions(+), 32 deletions(-)
>
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 3df2775760..146f0dcb40 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -402,29 +402,9 @@ static int vhost_vdpa_get_dev_features(struct vhost_dev 
> *dev,
>       return ret;
>   }
>   
> -static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
> -                               Error **errp)
> +static void vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v)
>   {
>       g_autoptr(GPtrArray) shadow_vqs = NULL;
> -    uint64_t dev_features, svq_features;
> -    int r;
> -    bool ok;
> -
> -    if (!v->shadow_vqs_enabled) {
> -        return 0;
> -    }
> -
> -    r = vhost_vdpa_get_dev_features(hdev, &dev_features);
> -    if (r != 0) {
> -        error_setg_errno(errp, -r, "Can't get vdpa device features");
> -        return r;
> -    }
> -
> -    svq_features = dev_features;
> -    ok = vhost_svq_valid_features(svq_features, errp);
> -    if (unlikely(!ok)) {
> -        return -1;
> -    }
>   
>       shadow_vqs = g_ptr_array_new_full(hdev->nvqs, vhost_svq_free);
>       for (unsigned n = 0; n < hdev->nvqs; ++n) {
> @@ -436,7 +416,6 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, 
> struct vhost_vdpa *v,
>       }
>   
>       v->shadow_vqs = g_steal_pointer(&shadow_vqs);
> -    return 0;
>   }
>   
>   static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
> @@ -461,11 +440,7 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void 
> *opaque, Error **errp)
>       dev->opaque =  opaque ;
>       v->listener = vhost_vdpa_memory_listener;
>       v->msg_type = VHOST_IOTLB_MSG_V2;
> -    ret = vhost_vdpa_init_svq(dev, v, errp);
> -    if (ret) {
> -        goto err;
> -    }
> -
> +    vhost_vdpa_init_svq(dev, v);
>       vhost_vdpa_get_iova_range(v);
>   
>       if (!vhost_vdpa_first_dev(dev)) {
> @@ -476,10 +451,6 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void 
> *opaque, Error **errp)
>                                  VIRTIO_CONFIG_S_DRIVER);
>   
>       return 0;
> -
> -err:
> -    ram_block_discard_disable(false);
> -    return ret;
>   }
>   
>   static void vhost_vdpa_host_notifier_uninit(struct vhost_dev *dev,
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index d3b1de481b..fb35b17ab4 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -117,9 +117,10 @@ static bool vhost_vdpa_net_valid_svq_features(uint64_t 
> features, Error **errp)
>       if (invalid_dev_features) {
>           error_setg(errp, "vdpa svq does not work with features 0x%" PRIx64,
>                      invalid_dev_features);
> +        return false;
>       }
>   
> -    return !invalid_dev_features;
> +    return vhost_svq_valid_features(features, errp);
>   }
>   
>   static int vhost_vdpa_net_check_device_id(struct vhost_net *net)