Re: [RFC PATCH v1] vhost-vsock: SOCK_SEQPACKET feature bit support

[Arseny Krasnov <arseny.krasnov@kaspersky.com>]

SOCK_SEQPACKET support for Linux already merged to net-next.
SOCK_SEQPACKET support for spec is here:
https://lists.oasis-open.org/archives/virtio-comment/202105/msg00017.html

On 21.06.2021 17:07, Arseny Krasnov wrote:
> This adds processing of VIRTIO_VSOCK_F_SEQPACKET features bit. Guest
> negotiates it with vhost, thus both will know that SOCK_SEQPACKET
> supported by peer.
>
> Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
> ---
>  hw/virtio/vhost-vsock.c                       | 16 +++++++++++++++-
>  include/standard-headers/linux/virtio_vsock.h |  3 +++
>  2 files changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/hw/virtio/vhost-vsock.c b/hw/virtio/vhost-vsock.c
> index 8ddfb9abfe..fc8c143df9 100644
> --- a/hw/virtio/vhost-vsock.c
> +++ b/hw/virtio/vhost-vsock.c
> @@ -108,10 +108,23 @@ static uint64_t vhost_vsock_get_features(VirtIODevice *vdev,
>                                           uint64_t requested_features,
>                                           Error **errp)
>  {
> -    /* No feature bits used yet */
> +    VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
> +
> +    if (virtio_has_feature(vvc->vhost_dev.features, VIRTIO_VSOCK_F_SEQPACKET)) {
> +        virtio_add_feature(&requested_features, VIRTIO_VSOCK_F_SEQPACKET);
> +    }
> +
>      return requested_features;
>  }
>  
> +static void vhost_vsock_set_features(VirtIODevice *vdev, uint64_t features)
> +{
> +    VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
> +    const VhostOps *vhost_ops = vvc->vhost_dev.vhost_ops;
> +
> +    vhost_ops->vhost_set_features(&vvc->vhost_dev, features);
> +}
> +
>  static const VMStateDescription vmstate_virtio_vhost_vsock = {
>      .name = "virtio-vhost_vsock",
>      .minimum_version_id = VHOST_VSOCK_SAVEVM_VERSION,
> @@ -224,6 +237,7 @@ static void vhost_vsock_class_init(ObjectClass *klass, void *data)
>      vdc->realize = vhost_vsock_device_realize;
>      vdc->unrealize = vhost_vsock_device_unrealize;
>      vdc->get_features = vhost_vsock_get_features;
> +    vdc->set_features = vhost_vsock_set_features;
>      vdc->get_config = vhost_vsock_get_config;
>      vdc->set_status = vhost_vsock_set_status;
>  }
> diff --git a/include/standard-headers/linux/virtio_vsock.h b/include/standard-headers/linux/virtio_vsock.h
> index be443211ce..5eac522ee2 100644
> --- a/include/standard-headers/linux/virtio_vsock.h
> +++ b/include/standard-headers/linux/virtio_vsock.h
> @@ -38,6 +38,9 @@
>  #include "standard-headers/linux/virtio_ids.h"
>  #include "standard-headers/linux/virtio_config.h"
>  
> +/* The feature bitmap for virtio vsock */
> +#define VIRTIO_VSOCK_F_SEQPACKET       1       /* SOCK_SEQPACKET supported */
> +
>  struct virtio_vsock_config {
>  	uint64_t guest_cid;
>  } QEMU_PACKED;