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Re: [Qemu-devel] [PATCH v2] virtio-net: add a field to indicate if vlan
From: |
Amos Kong |
Subject: |
Re: [Qemu-devel] [PATCH v2] virtio-net: add a field to indicate if vlan table is used |
Date: |
Fri, 21 Feb 2014 18:01:40 +0800 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Thu, Feb 20, 2014 at 12:46:14PM -0500, Vlad Yasevich wrote:
> On 02/20/2014 11:38 AM, Amos Kong wrote:
> > Stefan Fritsch just fixed a virtio-net driver bug [1], virtio-net won't
> > filter out VLAN-tagged packets if VIRTIO_NET_F_CTRL_VLAN isn't negotiated.
> >
> > This patch added a new field to @RxFilterInfo to indicate if management
> > uses the vlan table.
> >
> > [1] http://lists.nongnu.org/archive/html/qemu-devel/2014-02/msg02604.html
> >
> > Signed-off-by: Amos Kong <address@hidden>
> > ---
> > V2: don't make vlan-table optional, add a flag to indicate
> > if vlan table is used by management
> > ---
> > hw/net/virtio-net.c | 38 +++++++++++++++++++++++++-------------
> > qapi-schema.json | 3 +++
> > qmp-commands.hx | 2 ++
> > 3 files changed, 30 insertions(+), 13 deletions(-)
> >
> > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> > index 3626608..f591f4e 100644
> > --- a/hw/net/virtio-net.c
> > +++ b/hw/net/virtio-net.c
> > @@ -222,13 +222,33 @@ static char *mac_strdup_printf(const uint8_t *mac)
> > mac[1], mac[2], mac[3], mac[4], mac[5]);
> > }
> >
> > +static intList *get_vlan_table(VirtIONet *n)
> > +{
> > + intList *list, *entry;
> > + int i, j;
> > +
> > + list = NULL;
> > + for (i = 0; i < MAX_VLAN >> 5; i++) {
> > + for (j = 0; n->vlans[i] && j < 0x1f; j++) {
> > + if (n->vlans[i] & (1U << j)) {
> > + entry = g_malloc0(sizeof(*entry));
> > + entry->value = (i << 5) + j;
> > + entry->next = list;
> > + list = entry;
> > + }
> > + }
> > + }
> > +
> > + return list;
> > +}
> > +
> > static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
> > {
> > VirtIONet *n = qemu_get_nic_opaque(nc);
> > + VirtIODevice *vdev = VIRTIO_DEVICE(n);
> > RxFilterInfo *info;
> > strList *str_list, *entry;
> > - intList *int_list, *int_entry;
> > - int i, j;
> > + int i;
> >
> > info = g_malloc0(sizeof(*info));
> > info->name = g_strdup(nc->name);
> > @@ -273,19 +293,11 @@ static RxFilterInfo
> > *virtio_net_query_rxfilter(NetClientState *nc)
> > str_list = entry;
> > }
> > info->multicast_table = str_list;
> > + info->vlan_table = get_vlan_table(n);
> >
> > - int_list = NULL;
> > - for (i = 0; i < MAX_VLAN >> 5; i++) {
> > - for (j = 0; n->vlans[i] && j < 0x1f; j++) {
> > - if (n->vlans[i] & (1U << j)) {
> > - int_entry = g_malloc0(sizeof(*int_entry));
> > - int_entry->value = (i << 5) + j;
> > - int_entry->next = int_list;
> > - int_list = int_entry;
> > - }
> > - }
> > + if ((1 << VIRTIO_NET_F_CTRL_VLAN) & vdev->guest_features) {
> > + info->vlan = true;
> > }
>
> So, in the case that vlan filtering is not supported in the guest
> we get:
> "vlan": false,
> "vlan-table": [
> 0,
> 1,
> 2,
> ...
> 4095
> ]
> since virtio_net now initializes the table to all 1s.
> Seems a bit awkward. We are providing a lot of data that
> is simply going to be ignored.
In Stefan's patch [1], qemu fills all vlan ids to 1, then all the
packets will come to guest.
For the host device, it also should not filter out any vlan-tagged
packets when VIRTIO_NET_F_CTRL_VLAN is not negotiated. We should also
fill vlan ids of host device to 1, then vlan-filter of host device
will not perform.
If so, we don't need my patch, just pass [0,1,2,...4095] to management
as past. The new field in RxFilterInfo isn't necessary.
[1] [PATCH] virtio-net: Do not filter VLANs without F_CTRL_VLAN
Thanks, Amos
> > - info->vlan_table = int_list;
> >
> > /* enable event notification after query */
> > nc->rxfilter_notify_enabled = 1;
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index 7cfb5e5..5b54e94 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -4032,6 +4032,8 @@
> > #
> > # @unicast-overflow: unicast table is overflowed or not
> > #
> > +# @vlan: whether management uses the vlan table
> > +#
>
> The above description seems a bit confusing to me. The value
> we are returning describes whether or not qemu is performing
> vlan filtering. I am not sure if it has any bearing on what
> management may be doing.
>
> I think the idea is that management, in the future, would look at
> this value and make some decision about applying provided filter
> to the current host configuration.
>
> > # @main-mac: the main macaddr string
> > #
> > # @vlan-table: a list of active vlan id
> > @@ -4052,6 +4054,7 @@
> > 'broadcast-allowed': 'bool',
> > 'multicast-overflow': 'bool',
> > 'unicast-overflow': 'bool',
> > + 'vlan': 'bool',
>
> Not terribly descriptive. May be call it vlan-filter?
>
> Thanks
> -vlad
> > 'main-mac': 'str',
> > 'vlan-table': ['int'],
> > 'unicast-table': ['str'],
> > diff --git a/qmp-commands.hx b/qmp-commands.hx
> > index cce6b81..b170c79 100644
> > --- a/qmp-commands.hx
> > +++ b/qmp-commands.hx
> > @@ -3307,6 +3307,7 @@ Each array entry contains the following:
> > - "broadcast-allowed": allow to receive broadcast (json-bool)
> > - "multicast-overflow": multicast table is overflowed (json-bool)
> > - "unicast-overflow": unicast table is overflowed (json-bool)
> > +- "vlan": management uses the vlan table (json-bool)
> > - "main-mac": main macaddr string (json-string)
> > - "vlan-table": a json-array of active vlan id
> > - "unicast-table": a json-array of unicast macaddr string
> > @@ -3321,6 +3322,7 @@ Example:
> > "name": "vnet0",
> > "main-mac": "52:54:00:12:34:56",
> > "unicast": "normal",
> > + "vlan": true,
> > "vlan-table": [
> > 4,
> > 0
> >