On Tue, Mar 09, 2010 at 08:43:12AM -0600, Anthony Liguori wrote:
> On 03/09/2010 07:15 AM, Michael S. Tsirkin wrote:
>> New bridge in linux 2.6.34 adds IGMP snooping support,
>> after which bridge should not normally flood any packets.
>> While we still need mac table to arm forwarding tables
>> after migration, we can thus ignore it for rx datapath.
>>
>> For vlan, it's possible to do filtering down the
>> stack simply by using bridge per guest and binding said bridge
>> to vlan device, which some people do.
>>
>> Since qemu has no easy way to check IGMP snooping
>> support in bridge or how it's connected, add options
>> to disable rx filtering, so that management can set it
>> as appropriate.
>> Use these options to optimise virtio-net rx path.
>> We still ask guest for the list of vlans/macs for
>> migration.
>>
>> Signed-off-by: Michael S. Tsirkin<m...@redhat.com>
>>
>
> Can't this be achieved by just disabling the feature bits? IOW,
>
> ctrl_vq=0,ctrl_vlan=0?
>
> Regards,
>
> Anthony Liguori
It can, but then we won't be able to migrate to a host
that does not do the filtering in host kernel.
>> Cc: Alex Williamson<alex.william...@hp.com>
>> Cc: Andreas Plesner Jacobsen<a...@mutt.dk>
>> ---
>> hw/virtio-net.c | 10 +++++++++-
>> net.h | 12 +++++++++++-
>> 2 files changed, 20 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/virtio-net.c b/hw/virtio-net.c
>> index 5c0093e..01b45ed 100644
>> --- a/hw/virtio-net.c
>> +++ b/hw/virtio-net.c
>> @@ -47,6 +47,7 @@ typedef struct VirtIONet
>> uint8_t nomulti;
>> uint8_t nouni;
>> uint8_t nobcast;
>> + uint32_t filtering;
>> struct {
>> int in_use;
>> int first_multi;
>> @@ -475,12 +476,17 @@ static int receive_filter(VirtIONet *n, const uint8_t
>> *buf, int size)
>> ptr += sizeof(struct virtio_net_hdr);
>> }
>>
>> - if (!memcmp(&ptr[12], vlan, sizeof(vlan))) {
>> + if ((n->filtering& (0x1<< NICCONF_F_VLAN_FILTERING))&&
>> + !memcmp(&ptr[12], vlan, sizeof(vlan))) {
>> int vid = be16_to_cpup((uint16_t *)(ptr + 14))& 0xfff;
>> if (!(n->vlans[vid>> 5]& (1U<< (vid& 0x1f))))
>> return 0;
>> }
>>
>> + if (!(n->filtering& (0x1<< NICCONF_F_MAC_FILTERING))) {
>> + return 1;
>> + }
>> +
>> if (ptr[0]& 1) { // multicast
>> if (!memcmp(ptr, bcast, sizeof(bcast))) {
>> return !n->nobcast;
>> @@ -863,6 +869,8 @@ VirtIODevice *virtio_net_init(DeviceState *dev, NICConf
>> *conf)
>>
>> n->mac_table.macs = qemu_mallocz(MAC_TABLE_ENTRIES * ETH_ALEN);
>>
>> + n->filtering = conf->filtering;
>> +
>> n->vlans = qemu_mallocz(MAX_VLAN>> 3);
>>
>> register_savevm("virtio-net", virtio_net_id++, VIRTIO_NET_VM_VERSION,
>> diff --git a/net.h b/net.h
>> index 33a1eaf..459ede5 100644
>> --- a/net.h
>> +++ b/net.h
>> @@ -18,12 +18,22 @@ typedef struct NICConf {
>> MACAddr macaddr;
>> VLANState *vlan;
>> VLANClientState *peer;
>> + uint32_t filtering;
>> } NICConf;
>>
>> +enum {
>> + NICCONF_F_MAC_FILTERING = 0,
>> + NICCONF_F_VLAN_FILTERING = 1
>> +};
>> +
>> #define DEFINE_NIC_PROPERTIES(_state, _conf) \
>> DEFINE_PROP_MACADDR("mac", _state, _conf.macaddr), \
>> DEFINE_PROP_VLAN("vlan", _state, _conf.vlan), \
>> - DEFINE_PROP_NETDEV("netdev", _state, _conf.peer)
>> + DEFINE_PROP_NETDEV("netdev", _state, _conf.peer), \
>> + DEFINE_PROP_BIT("mac_filtering", _state, _conf.filtering, \
>> + NICCONF_F_MAC_FILTERING, true) \
>> + DEFINE_PROP_BIT("vlan_filtering", _state, _conf.filtering, \
>> + NICCONF_F_VLAN_FILTERING, true) \
>>
>> /* VLANs support */
>>
>>
