Re: [PATCH 3/3] virtio-net: Introduce hash report feature

["Michael S. Tsirkin" <mst@redhat.com>]

On Sat, Feb 29, 2020 at 07:13:01PM +0200, Yuri Benditovich wrote:
> The feature VIRTIO_NET_F_HASH_REPORT extends the
> layout of the packet and requests the device to
> calculate hash on incoming packets and report it
> in the packet header.
> 
> Signed-off-by: Yuri Benditovich <yuri.benditovich@daynix.com>
> ---
>  include/uapi/linux/virtio_net.h | 36 +++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> index 7a342657fb6c..6d7230469c57 100644
> --- a/include/uapi/linux/virtio_net.h
> +++ b/include/uapi/linux/virtio_net.h
> @@ -57,6 +57,7 @@
>  					 * Steering */
>  #define VIRTIO_NET_F_CTRL_MAC_ADDR 23	/* Set MAC address */
>  
> +#define VIRTIO_NET_F_HASH_REPORT  57	/* Supports hash report */
>  #define VIRTIO_NET_F_RSS	  60	/* Supports RSS RX steering */
>  #define VIRTIO_NET_F_RSC_EXT	  61	/* extended coalescing info */
>  #define VIRTIO_NET_F_STANDBY	  62	/* Act as standby for another device
> @@ -144,6 +145,23 @@ struct virtio_net_hdr_v1 {
>  	__virtio16 num_buffers;	/* Number of merged rx buffers */
>  };
>  
> +struct virtio_net_hdr_v1_hash {
> +	struct virtio_net_hdr_v1 hdr;
> +	__virtio32 hash_value;
> +#define VIRTIO_NET_HASH_REPORT_NONE            0
> +#define VIRTIO_NET_HASH_REPORT_IPv4            1
> +#define VIRTIO_NET_HASH_REPORT_TCPv4           2
> +#define VIRTIO_NET_HASH_REPORT_UDPv4           3
> +#define VIRTIO_NET_HASH_REPORT_IPv6            4
> +#define VIRTIO_NET_HASH_REPORT_TCPv6           5
> +#define VIRTIO_NET_HASH_REPORT_UDPv6           6
> +#define VIRTIO_NET_HASH_REPORT_IPv6_EX         7
> +#define VIRTIO_NET_HASH_REPORT_TCPv6_EX        8
> +#define VIRTIO_NET_HASH_REPORT_UDPv6_EX        9
> +	__virtio16 hash_report;
> +	__virtio16 padding;
> +};
> +
>  #ifndef VIRTIO_NET_NO_LEGACY
>  /* This header comes first in the scatter-gather list.
>   * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, it must
> @@ -292,6 +310,24 @@ struct virtio_net_rss_config {
>  
>   #define VIRTIO_NET_CTRL_MQ_RSS_CONFIG          1
>  
> +/*
> + * The command VIRTIO_NET_CTRL_MQ_HASH_CONFIG requests the device
> + * to include in the virtio header of the packet the value of the
> + * calculated hash and the report type of hash. It also provides
> + * parameters for hash calculation. The command requires feature
> + * VIRTIO_NET_F_HASH_REPORT to be negotiated to extend the
> + * layout of virtio header as defined in virtio_net_hdr_v1_hash.
> + */
> +struct virtio_net_hash_config {
> +	__virtio32 hash_types;
> +	/* for compatibility with virtio_net_rss_config */
> +	__virtio16 reserved[4];

I expect these should all be le32/le16 respectively.

> +	__u8 hash_key_length;
> +	__u8 hash_key_data[/*hash_key_length*/];
> +};

Should be /* hash_key_length */ as per coding style.

> +
> + #define VIRTIO_NET_CTRL_MQ_HASH_CONFIG         2
> +
>  /*
>   * Control network offloads
>   *
> -- 
> 2.17.1