Re: [Qemu-devel] [PATCH 6/7] virtio-net: Add new RX filter controls

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

On Fri, Jun 05, 2009 at 02:47:18PM -0600, Alex Williamson wrote:
> Add a few new RX modes to better control the receive_filter.  These
> are all fairly obvious features that hardware could provide.

Could you add a bit more detail on motivation for these
features please?


> 
> Signed-off-by: Alex Williamson <alex.williamson@hp.com>
> ---
> 
>  hw/virtio-net.c |   40 ++++++++++++++++++++++++++++++++++++----
>  hw/virtio-net.h |   14 ++++++++++----
>  2 files changed, 46 insertions(+), 8 deletions(-)
> 
> diff --git a/hw/virtio-net.c b/hw/virtio-net.c
> index 5239cc0..ecb58de 100644
> --- a/hw/virtio-net.c
> +++ b/hw/virtio-net.c
> @@ -16,7 +16,7 @@
>  #include "qemu-timer.h"
>  #include "virtio-net.h"
>  
> -#define VIRTIO_NET_VM_VERSION    9
> +#define VIRTIO_NET_VM_VERSION    10
>  
>  #define MAC_TABLE_ENTRIES    32
>  #define MAX_VLAN    (1 << 12)   /* Per 802.1Q definition */
> @@ -35,6 +35,10 @@ typedef struct VirtIONet
>      int mergeable_rx_bufs;
>      uint8_t promisc;
>      uint8_t allmulti;
> +    uint8_t alluni;
> +    uint8_t nomulti;
> +    uint8_t nouni;
> +    uint8_t nobcast;
>      struct {
>          int in_use;
>          int first_multi;
> @@ -98,6 +102,10 @@ static void virtio_net_reset(VirtIODevice *vdev)
>      /* Reset back to compatibility mode */
>      n->promisc = 1;
>      n->allmulti = 0;
> +    n->alluni = 0;
> +    n->nomulti = 0;
> +    n->nouni = 0;
> +    n->nobcast = 0;
>  
>      /* Flush any MAC and VLAN filter table state */
>      n->mac_table.in_use = 0;
> @@ -114,7 +122,8 @@ static uint32_t virtio_net_get_features(VirtIODevice *vdev)
>                          (1 << VIRTIO_NET_F_STATUS) |
>                          (1 << VIRTIO_NET_F_CTRL_VQ) |
>                          (1 << VIRTIO_NET_F_CTRL_RX) |
> -                        (1 << VIRTIO_NET_F_CTRL_VLAN);
> +                        (1 << VIRTIO_NET_F_CTRL_VLAN) |
> +                        (1 << VIRTIO_NET_F_CTRL_RX_EXTRA);
>  
>      return features;
>  }
> @@ -157,6 +166,14 @@ static int virtio_net_handle_rx_mode(VirtIONet *n, uint8_t cmd,
>          n->promisc = on;
>      else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLMULTI)
>          n->allmulti = on;
> +    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_ALLUNI)
> +        n->alluni = on;
> +    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOMULTI)
> +        n->nomulti = on;
> +    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOUNI)
> +        n->nouni = on;
> +    else if (cmd == VIRTIO_NET_CTRL_RX_MODE_NOBCAST)
> +        n->nobcast = on;
>      else
>          return VIRTIO_NET_ERR;
>  
> @@ -357,7 +374,9 @@ static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
>  
>      if (ptr[0] & 1) { // multicast
>          if (!memcmp(ptr, bcast, sizeof(bcast))) {
> -            return 1;
> +            return !n->nobcast;
> +        } else if (n->nomulti) {
> +            return 0;
>          } else if (n->allmulti || n->mac_table.multi_overflow) {
>              return 1;
>          }
> @@ -368,7 +387,9 @@ static int receive_filter(VirtIONet *n, const uint8_t *buf, int size)
>              }
>          }
>      } else { // unicast
> -        if (n->mac_table.uni_overflow) {
> +        if (n->nouni) {
> +            return 0;
> +        } else if (n->alluni || n->mac_table.uni_overflow) {
>              return 1;
>          } else if (!memcmp(ptr, n->mac, ETH_ALEN)) {
>              return 1;
> @@ -549,6 +570,10 @@ static void virtio_net_save(QEMUFile *f, void *opaque)
>      qemu_put_be32(f, 0); /* vnet-hdr placeholder */
>      qemu_put_byte(f, n->mac_table.multi_overflow);
>      qemu_put_byte(f, n->mac_table.uni_overflow);
> +    qemu_put_byte(f, n->alluni);
> +    qemu_put_byte(f, n->nomulti);
> +    qemu_put_byte(f, n->nouni);
> +    qemu_put_byte(f, n->nobcast);
>  }
>  
>  static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
> @@ -605,6 +630,13 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
>          n->mac_table.uni_overflow = qemu_get_byte(f);
>      }
>  
> +    if (version_id >= 10) {
> +        n->alluni = qemu_get_byte(f);
> +        n->nomulti = qemu_get_byte(f);
> +        n->nouni = qemu_get_byte(f);
> +        n->nobcast = qemu_get_byte(f);
> +    }
> +
>      /* Find the first multicast entry in the saved MAC filter */
>      for (i = 0; i < n->mac_table.in_use; i++) {
>          if (n->mac_table.macs[i * ETH_ALEN] & 1) {
> diff --git a/hw/virtio-net.h b/hw/virtio-net.h
> index 390fe10..2085181 100644
> --- a/hw/virtio-net.h
> +++ b/hw/virtio-net.h
> @@ -43,6 +43,7 @@
>  #define VIRTIO_NET_F_CTRL_VQ    17      /* Control channel available */
>  #define VIRTIO_NET_F_CTRL_RX    18      /* Control channel RX mode support */
>  #define VIRTIO_NET_F_CTRL_VLAN  19      /* Control channel VLAN filtering */
> +#define VIRTIO_NET_F_CTRL_RX_EXTRA 20   /* Extra RX mode control support */
>  
>  #define VIRTIO_NET_S_LINK_UP    1       /* Link is up */
>  
> @@ -103,14 +104,19 @@ typedef uint8_t virtio_net_ctrl_ack;
>  #define VIRTIO_NET_ERR    1
>  
>  /*
> - * Control the RX mode, ie. promisucous and allmulti.  PROMISC and
> - * ALLMULTI commands require an "out" sg entry containing a 1 byte
> - * state value, zero = disable, non-zero = enable.  These commands
> - * are supported with the VIRTIO_NET_F_CTRL_RX feature.
> + * Control the RX mode, ie. promisucous, allmulti, etc...
> + * All commands require an "out" sg entry containing a 1 byte
> + * state value, zero = disable, non-zero = enable.  Commands
> + * 0 and 1 are supported with the VIRTIO_NET_F_CTRL_RX feature.
> + * Commands 2-5 are added with VIRTIO_NET_F_CTRL_RX_EXTRA.
>   */
>  #define VIRTIO_NET_CTRL_RX_MODE    0
>   #define VIRTIO_NET_CTRL_RX_MODE_PROMISC      0
>   #define VIRTIO_NET_CTRL_RX_MODE_ALLMULTI     1
> + #define VIRTIO_NET_CTRL_RX_MODE_ALLUNI       2
> + #define VIRTIO_NET_CTRL_RX_MODE_NOMULTI      3
> + #define VIRTIO_NET_CTRL_RX_MODE_NOUNI        4
> + #define VIRTIO_NET_CTRL_RX_MODE_NOBCAST      5
>  
>  /*
>   * Control the MAC filter table.
> 
> 

-- 
MST