Re: [PATCH 3/3] vdpa: Support VLAN on nic control shadow virtqueue

[Jason Wang]

On Wed, Sep 7, 2022 at 12:36 AM Eugenio Pérez <eperezma@redhat.com> wrote:
>
> Update the virtio-net device model with each guest's update of vlan
> through control virtqueue, and accept creating a SVQ with a device
> exposing vlan feature bit.
>
> Done in the same commit since a malicious guest could send vlan
> commands otherwise.
>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
>  net/vhost-vdpa.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index ecbfd08eb9..40f7c60399 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -94,6 +94,7 @@ static const uint64_t vdpa_svq_device_features =
>      BIT_ULL(VIRTIO_NET_F_MRG_RXBUF) |
>      BIT_ULL(VIRTIO_NET_F_STATUS) |
>      BIT_ULL(VIRTIO_NET_F_CTRL_VQ) |
> +    BIT_ULL(VIRTIO_NET_F_CTRL_VLAN) |
>      BIT_ULL(VIRTIO_NET_F_MQ) |
>      BIT_ULL(VIRTIO_F_ANY_LAYOUT) |
>      BIT_ULL(VIRTIO_NET_F_CTRL_MAC_ADDR) |
> @@ -538,6 +539,16 @@ static bool vhost_vdpa_net_cvq_validate_cmd(const void 
> *out_buf, size_t len)
>                            __func__, ctrl.cmd);
>          };
>          break;
> +    case VIRTIO_NET_CTRL_VLAN:
> +        switch (ctrl->cmd) {
> +        case VIRTIO_NET_CTRL_VLAN_ADD:
> +        case VIRTIO_NET_CTRL_VLAN_DEL:
> +            return true;
> +        default:
> +            qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid vlan cmd %u\n",
> +                          __func__, ctrl->cmd);
> +        };

Considering we may add more features here, is it still worthwhile to
keep a whitelist like this?

Thanks

> +        break;
>      default:
>          qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid control class %u\n",
>                        __func__, ctrl.class);
> --
> 2.31.1
>