Re: [PATCH v3 2/3] virtio-net: Introduce RSS receive steering feature

[Michael S. Tsirkin]

On Mon, Mar 02, 2020 at 10:53:14AM +0200, Yuri Benditovich wrote:
> On Sun, Mar 1, 2020 at 9:58 PM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote:
> >
> > On Sun, Mar 01, 2020 at 04:33:01PM +0200, Yuri Benditovich wrote:
> > > RSS (Receive-side scaling) defines hash calculation
> > > rules and decision on receive virtqueue according to
> > > the calculated hash, provided mask to apply and
> > > provided indirection table containing indices of
> > > receive virqueues. The driver sends the control
> > > command to enable multiqueue and provide parameters
> > > for receive steering.
> > >
> > > Signed-off-by: Yuri Benditovich <yuri.benditovich@xxxxxxxxxx>
> > > ---
> > >  include/uapi/linux/virtio_net.h | 42 +++++++++++++++++++++++++++++++--
> > >  1 file changed, 40 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
> > > index 19e76b3e3a64..188ad3eecdc8 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_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
> > >                                        * with the same MAC.
> > > @@ -70,6 +71,17 @@
> > >  #define VIRTIO_NET_S_LINK_UP 1       /* Link is up */
> > >  #define VIRTIO_NET_S_ANNOUNCE        2       /* Announcement is needed */
> > >
> > > +/* supported/enabled hash types */
> > > +#define VIRTIO_NET_RSS_HASH_TYPE_IPv4          (1 << 0)
> > > +#define VIRTIO_NET_RSS_HASH_TYPE_TCPv4         (1 << 1)
> > > +#define VIRTIO_NET_RSS_HASH_TYPE_UDPv4         (1 << 2)
> > > +#define VIRTIO_NET_RSS_HASH_TYPE_IPv6          (1 << 3)
> > > +#define VIRTIO_NET_RSS_HASH_TYPE_TCPv6         (1 << 4)
> > > +#define VIRTIO_NET_RSS_HASH_TYPE_UDPv6         (1 << 5)
> > > +#define VIRTIO_NET_RSS_HASH_TYPE_IP_EX         (1 << 6)
> > > +#define VIRTIO_NET_RSS_HASH_TYPE_TCP_EX        (1 << 7)
> > > +#define VIRTIO_NET_RSS_HASH_TYPE_UDP_EX        (1 << 8)
> > > +
> > >  struct virtio_net_config {
> > >       /* The config defining mac address (if VIRTIO_NET_F_MAC) */
> > >       __u8 mac[ETH_ALEN];
> > > @@ -93,6 +105,12 @@ struct virtio_net_config {
> > >        * Any other value stands for unknown.
> > >        */
> > >       __u8 duplex;
> > > +     /* maximum size of RSS key */
> > > +     __u8 rss_max_key_size;
> > > +     /* maximum number of indirection table entries */
> > > +     __le16 rss_max_indirection_table_length;
> > > +     /* bitmask of supported VIRTIO_NET_RSS_HASH_ types */
> > > +     __le32 supported_hash_types;
> > >  } __attribute__((packed));
> > >
> > >  /*
> > > @@ -246,7 +264,9 @@ struct virtio_net_ctrl_mac {
> > >
> > >  /*
> > >   * Control Receive Flow Steering
> > > - *
> > > + */
> > > +#define VIRTIO_NET_CTRL_MQ   4
> > > +/*
> > >   * The command VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET
> > >   * enables Receive Flow Steering, specifying the number of the transmit and
> > >   * receive queues that will be used. After the command is consumed and acked by
> > > @@ -259,11 +279,29 @@ struct virtio_net_ctrl_mq {
> > >       __virtio16 virtqueue_pairs;
> > >  };
> > >
> > > -#define VIRTIO_NET_CTRL_MQ   4
> > >   #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET        0
> > >   #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MIN        1
> > >   #define VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX        0x8000
> > >
> > > +/*
> > > + * The command VIRTIO_NET_CTRL_MQ_RSS_CONFIG has the same effect as
> > > + * VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET does and additionally configures
> > > + * the receive steering to use a hash calculated for incoming packet
> > > + * to decide on receive virtqueue to place the packet. The command
> > > + * also provides parameters to calculate a hash and receive virtqueue.
> > > + */
> > > +struct virtio_net_rss_config {
> > > +     __le32 hash_types;
> > > +     __le16 indirection_table_mask;
> > > +     __le16 unclassified_queue;
> > > +     __le16 indirection_table[1/* + indirection_table_mask */];
> > > +     __le16 max_tx_vq;
> > > +     __u8 hash_key_length;
> > > +     __u8 hash_key_data[/* hash_key_length */];
> > > +};
> > > +
> > > + #define VIRTIO_NET_CTRL_MQ_RSS_CONFIG          1
> > > +
> >
> >
> > Extra space here.
> 
> Where exactly you want to remove the empty line?
> The format here is exactly as in other places:
> comment - structure - space - command - space

+ #define VIRTIO_NET_CTRL_MQ_RSS_CONFIG          1

should be

+#define VIRTIO_NET_CTRL_MQ_RSS_CONFIG          1

> 
> >
> > >  /*
> > >   * Control network offloads
> > >   *
> > > --
> > > 2.17.1
> >