Re: [Qemu-devel] [PATCH v6] net: add support of mac-programming over macvtap in QEMU side

[Luiz Capitulino]

On Fri, 14 Jun 2013 15:45:52 +0800
Amos Kong <address@hidden> wrote:

> Currently macvtap based macvlan device is working in promiscuous
> mode, we want to implement mac-programming over macvtap through
> Libvirt for better performance.
> 
> Design:
>  QEMU notifies Libvirt when rx-filter config is changed in guest,
>  then Libvirt query the rx-filter information by a monitor command,
>  and sync the change to macvtap device. Related rx-filter config
>  of the nic contains main mac, rx-mode items and vlan table.
> 
> This patch adds a QMP event to notify management of rx-filter change,
> and adds a monitor command for management to query rx-filter
> information.
> 
> Test:
>  If we repeatedly add/remove vlan, and change macaddr of vlan
>  interfaces in guest by a loop script.
> 
> Result:
>  The events will flood the QMP client(management), management takes
>  too much resource to process the events.
> 
>  Event_throttle API (set rate to 1 ms) can avoid the events to flood

I doubt this is a valid value. Today, the three events that use the event
throttle API set the delay rate to 1000 ms.

>  QMP client, but it could cause an unexpected delay (~1ms), guests
>  guests normally expect rx-filter updates immediately.

What you mean by "immediately"? There's a round-trip to the host plus
all the stuff QEMU will execute to fulfil the request. And how did you
measure this, btw?

What you have to do is is to measure your test-case in three different
scenarios:

 1. Against upstream QEMU (ie. no patches)
 2. With the event throttle API
 3. With this patch

Only then you'll be able which is better.

> 
>  So we use a flag for each nic to avoid events flooding, the event
>  is emitted once until the query command is executed. The flag
>  implementation could not introduce unexpected delay.
> 
> There maybe exist an uncontrollable delay if we let Libvirt do the
> real change, guests normally expect rx-filter updates immediately.
> But it's another separate issue, we can investigate it when the
> work in Libvirt side is done.
> 
> Signed-off-by: Amos Kong <address@hidden>
> ---
> v2: add argument to filter mac-table info of single nic (Stefan)
>     update the document, add event notification
> v3: rename to rx-filter, add main mac, avoid events flooding (MST)
>     fix error process (Stefan), fix qmp interface (Eric)
> v4: process qerror in hmp, cleanup (Luiz)
>     set flag for each device, add device path in event, add
>     helper for g_strdup_printf (MST)
>     fix qmp document (Eric)
> v5: add path in doc, define notify flag to unsigned (Eric)
>     add vlan table (Jason), drop monitor cmd
> v6: return vids list, add test results/analysis to commitlog
> ---
>  QMP/qmp-events.txt        |  17 ++++++++
>  hw/net/virtio-net.c       | 108 
> ++++++++++++++++++++++++++++++++++++++++++++++
>  include/monitor/monitor.h |   1 +
>  include/net/net.h         |   3 ++
>  monitor.c                 |   1 +
>  net/net.c                 |  47 ++++++++++++++++++++
>  qapi-schema.json          |  75 ++++++++++++++++++++++++++++++++
>  qmp-commands.hx           |  63 +++++++++++++++++++++++++++
>  8 files changed, 315 insertions(+)
> 
> diff --git a/QMP/qmp-events.txt b/QMP/qmp-events.txt
> index 24e804e9..39b6016 100644
> --- a/QMP/qmp-events.txt
> +++ b/QMP/qmp-events.txt
> @@ -172,6 +172,23 @@ Data:
>    },
>    "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
>  
> +NIC_RX_FILTER_CHANGED
> +-----------------
> +
> +The event is emitted once until the query command is executed,
> +the first event will always be emitted.
> +
> +Data:
> +
> +- "name": net client name (json-string)
> +- "path": device path (json-string)
> +
> +{ "event": "NIC_RX_FILTER_CHANGED",
> +  "data": { "name": "vnet0",
> +            "path": "/machine/peripheral/vnet0/virtio-backend" },
> +  "timestamp": { "seconds": 1368697518, "microseconds": 326866 } }
> +}
> +
>  RESET
>  -----
>  
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 1ea9556..4137959 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -21,6 +21,8 @@
>  #include "hw/virtio/virtio-net.h"
>  #include "net/vhost_net.h"
>  #include "hw/virtio/virtio-bus.h"
> +#include "qapi/qmp/qjson.h"
> +#include "monitor/monitor.h"
>  
>  #define VIRTIO_NET_VM_VERSION    11
>  
> @@ -192,6 +194,100 @@ static void virtio_net_set_link_status(NetClientState 
> *nc)
>      virtio_net_set_status(vdev, vdev->status);
>  }
>  
> +static void rxfilter_notify(NetClientState *nc)
> +{
> +    QObject *event_data;
> +    VirtIONet *n = qemu_get_nic_opaque(nc);
> +
> +    if (nc->rxfilter_notify_enabled) {
> +        event_data = qobject_from_jsonf("{ 'name': %s, 'path': %s }",
> +                           n->netclient_name,
> +                           object_get_canonical_path(OBJECT(n->qdev)));
> +        monitor_protocol_event(QEVENT_NIC_RX_FILTER_CHANGED, event_data);
> +        qobject_decref(event_data);
> +
> +        /* disable event notification to avoid events flooding */
> +        nc->rxfilter_notify_enabled = 0;
> +    }
> +}
> +
> +static char *mac_strdup_printf(const uint8_t *mac)
> +{
> +    return g_strdup_printf("%.2x:%.2x:%.2x:%.2x:%.2x:%.2x", mac[0],
> +                            mac[1], mac[2], mac[3], mac[4], mac[5]);
> +}
> +
> +static RxFilterInfo *virtio_net_query_rxfilter(NetClientState *nc)
> +{
> +    VirtIONet *n = qemu_get_nic_opaque(nc);
> +    RxFilterInfo *info;
> +    strList *str_list = NULL;
> +    strList *entry;
> +    intList *int_list = NULL;
> +    intList *int_entry;
> +    int i, j;
> +
> +    info = g_malloc0(sizeof(*info));
> +    info->name = g_strdup(nc->name);
> +    info->promiscuous = n->promisc;
> +
> +    if (n->nouni) {
> +        info->unicast = RX_STATE_NONE;
> +    } else if (n->alluni) {
> +        info->unicast = RX_STATE_ALL;
> +    } else {
> +        info->unicast = RX_STATE_NORMAL;
> +    }
> +
> +    if (n->nomulti) {
> +        info->multicast = RX_STATE_NONE;
> +    } else if (n->allmulti) {
> +        info->multicast = RX_STATE_ALL;
> +    } else {
> +        info->multicast = RX_STATE_NORMAL;
> +    }
> +
> +    info->broadcast_allowed = n->nobcast;
> +    info->multicast_overflow = n->mac_table.multi_overflow;
> +    info->unicast_overflow = n->mac_table.uni_overflow;
> +
> +    info->main_mac = mac_strdup_printf(n->mac);
> +
> +    for (i = 0; i < n->mac_table.first_multi; i++) {
> +        entry = g_malloc0(sizeof(*entry));
> +        entry->value = mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN);
> +        entry->next = str_list;
> +        str_list = entry;
> +    }
> +    info->unicast_table = str_list;
> +
> +    str_list = NULL;
> +    for (i = n->mac_table.first_multi; i < n->mac_table.in_use; i++) {
> +        entry = g_malloc0(sizeof(*entry));
> +        entry->value = mac_strdup_printf(n->mac_table.macs + i * ETH_ALEN);
> +        entry->next = str_list;
> +        str_list = entry;
> +    }
> +    info->multicast_table = str_list;
> +
> +    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;
> +            }
> +        }
> +    }
> +    info->vlan_table = int_list;
> +
> +    /* enable event notification after query */
> +    nc->rxfilter_notify_enabled = 1;
> +
> +    return info;
> +}
> +
>  static void virtio_net_reset(VirtIODevice *vdev)
>  {
>      VirtIONet *n = VIRTIO_NET(vdev);
> @@ -420,6 +516,7 @@ static int virtio_net_handle_rx_mode(VirtIONet *n, 
> uint8_t cmd,
>  {
>      uint8_t on;
>      size_t s;
> +    NetClientState *nc = qemu_get_queue(n->nic);
>  
>      s = iov_to_buf(iov, iov_cnt, 0, &on, sizeof(on));
>      if (s != sizeof(on)) {
> @@ -442,6 +539,8 @@ static int virtio_net_handle_rx_mode(VirtIONet *n, 
> uint8_t cmd,
>          return VIRTIO_NET_ERR;
>      }
>  
> +    rxfilter_notify(nc);
> +
>      return VIRTIO_NET_OK;
>  }
>  
> @@ -487,6 +586,7 @@ static int virtio_net_handle_mac(VirtIONet *n, uint8_t 
> cmd,
>  {
>      struct virtio_net_ctrl_mac mac_data;
>      size_t s;
> +    NetClientState *nc = qemu_get_queue(n->nic);
>  
>      if (cmd == VIRTIO_NET_CTRL_MAC_ADDR_SET) {
>          if (iov_size(iov, iov_cnt) != sizeof(n->mac)) {
> @@ -495,6 +595,8 @@ static int virtio_net_handle_mac(VirtIONet *n, uint8_t 
> cmd,
>          s = iov_to_buf(iov, iov_cnt, 0, &n->mac, sizeof(n->mac));
>          assert(s == sizeof(n->mac));
>          qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
> +        rxfilter_notify(nc);
> +
>          return VIRTIO_NET_OK;
>      }
>  
> @@ -559,6 +661,8 @@ static int virtio_net_handle_mac(VirtIONet *n, uint8_t 
> cmd,
>          n->mac_table.multi_overflow = 1;
>      }
>  
> +    rxfilter_notify(nc);
> +
>      return VIRTIO_NET_OK;
>  }
>  
> @@ -567,6 +671,7 @@ static int virtio_net_handle_vlan_table(VirtIONet *n, 
> uint8_t cmd,
>  {
>      uint16_t vid;
>      size_t s;
> +    NetClientState *nc = qemu_get_queue(n->nic);
>  
>      s = iov_to_buf(iov, iov_cnt, 0, &vid, sizeof(vid));
>      vid = lduw_p(&vid);
> @@ -584,6 +689,8 @@ static int virtio_net_handle_vlan_table(VirtIONet *n, 
> uint8_t cmd,
>      else
>          return VIRTIO_NET_ERR;
>  
> +    rxfilter_notify(nc);
> +
>      return VIRTIO_NET_OK;
>  }
>  
> @@ -1312,6 +1419,7 @@ static NetClientInfo net_virtio_info = {
>      .receive = virtio_net_receive,
>          .cleanup = virtio_net_cleanup,
>      .link_status_changed = virtio_net_set_link_status,
> +    .query_rx_filter = virtio_net_query_rxfilter,
>  };
>  
>  static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
> diff --git a/include/monitor/monitor.h b/include/monitor/monitor.h
> index 1a6cfcf..1942cc4 100644
> --- a/include/monitor/monitor.h
> +++ b/include/monitor/monitor.h
> @@ -41,6 +41,7 @@ typedef enum MonitorEvent {
>      QEVENT_BLOCK_JOB_READY,
>      QEVENT_DEVICE_DELETED,
>      QEVENT_DEVICE_TRAY_MOVED,
> +    QEVENT_NIC_RX_FILTER_CHANGED,
>      QEVENT_SUSPEND,
>      QEVENT_SUSPEND_DISK,
>      QEVENT_WAKEUP,
> diff --git a/include/net/net.h b/include/net/net.h
> index 43d85a1..30e4b04 100644
> --- a/include/net/net.h
> +++ b/include/net/net.h
> @@ -49,6 +49,7 @@ typedef ssize_t (NetReceiveIOV)(NetClientState *, const 
> struct iovec *, int);
>  typedef void (NetCleanup) (NetClientState *);
>  typedef void (LinkStatusChanged)(NetClientState *);
>  typedef void (NetClientDestructor)(NetClientState *);
> +typedef RxFilterInfo *(QueryRxFilter)(NetClientState *);
>  
>  typedef struct NetClientInfo {
>      NetClientOptionsKind type;
> @@ -59,6 +60,7 @@ typedef struct NetClientInfo {
>      NetCanReceive *can_receive;
>      NetCleanup *cleanup;
>      LinkStatusChanged *link_status_changed;
> +    QueryRxFilter *query_rx_filter;
>      NetPoll *poll;
>  } NetClientInfo;
>  
> @@ -74,6 +76,7 @@ struct NetClientState {
>      unsigned receive_disabled : 1;
>      NetClientDestructor *destructor;
>      unsigned int queue_index;
> +    unsigned rxfilter_notify_enabled:1;
>  };
>  
>  typedef struct NICState {
> diff --git a/monitor.c b/monitor.c
> index 017411f..3b8117c 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -490,6 +490,7 @@ static const char *monitor_event_names[] = {
>      [QEVENT_BLOCK_JOB_READY] = "BLOCK_JOB_READY",
>      [QEVENT_DEVICE_DELETED] = "DEVICE_DELETED",
>      [QEVENT_DEVICE_TRAY_MOVED] = "DEVICE_TRAY_MOVED",
> +    [QEVENT_NIC_RX_FILTER_CHANGED] = "NIC_RX_FILTER_CHANGED",
>      [QEVENT_SUSPEND] = "SUSPEND",
>      [QEVENT_SUSPEND_DISK] = "SUSPEND_DISK",
>      [QEVENT_WAKEUP] = "WAKEUP",
> diff --git a/net/net.c b/net/net.c
> index 43a74e4..33abffe 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -961,6 +961,53 @@ void print_net_client(Monitor *mon, NetClientState *nc)
>                     nc->info_str);
>  }
>  
> +RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name,
> +                                      Error **errp)
> +{
> +    NetClientState *nc;
> +    RxFilterInfoList *filter_list = NULL, *last_entry = NULL;
> +
> +    QTAILQ_FOREACH(nc, &net_clients, next) {
> +        RxFilterInfoList *entry;
> +        RxFilterInfo *info;
> +
> +        /* only query rx-filter information of nic */
> +        if (nc->info->type != NET_CLIENT_OPTIONS_KIND_NIC) {
> +            continue;
> +        }
> +        if (has_name && strcmp(nc->name, name) != 0) {
> +            continue;
> +        }
> +
> +        if (nc->info->query_rx_filter) {
> +            info = nc->info->query_rx_filter(nc);
> +            entry = g_malloc0(sizeof(*entry));
> +            entry->value = info;
> +
> +            if (!filter_list) {
> +                filter_list = entry;
> +            } else {
> +                last_entry->next = entry;
> +            }
> +            last_entry = entry;
> +        } else if (has_name) {
> +            error_setg(errp, "net client(%s) doesn't support"
> +                       " rx-filter querying", name);
> +            break;
> +        }
> +    }
> +
> +    if (filter_list == NULL && !error_is_set(errp)) {
> +        if (has_name) {
> +            error_setg(errp, "invalid net client name: %s", name);
> +        } else {
> +            error_setg(errp, "no net client supports rx-filter querying");
> +        }
> +    }
> +
> +    return filter_list;
> +}
> +
>  void do_info_network(Monitor *mon, const QDict *qdict)
>  {
>      NetClientState *nc, *peer;
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 5ad6894..a69dc17 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -3624,3 +3624,78 @@
>              '*cpuid-input-ecx': 'int',
>              'cpuid-register': 'X86CPURegister32',
>              'features': 'int' } }
> +
> +##
> +# @RxState:
> +#
> +# Packets receiving state
> +#
> +# @normal: filter assigned packets according to the mac-table
> +#
> +# @none: don't receive any assigned packet
> +#
> +# @all: receive all assigned packets
> +#
> +##
> +{ 'enum': 'RxState', 'data': [ 'normal', 'none', 'all' ] }
> +
> +##
> +# @RxFilterInfo:
> +#
> +# Rx-filter information for a nic.
> +#
> +# @name: net client name
> +#
> +# @promiscuous: whether promiscuous mode is enabled
> +#
> +# @multicast: multicast receive state
> +#
> +# @unicast: unicast receive state
> +#
> +# @broadcast-allowed: whether to receive broadcast
> +#
> +# @multicast-overflow: multicast table is overflowed or not
> +#
> +# @unicast-overflow: unicast table is overflowed or not
> +#
> +# @main-mac: the main macaddr string
> +#
> +# @vlan-table: a list of active vlan id
> +#
> +# @unicast-table: a list of unicast macaddr string
> +#
> +# @multicast-table: a list of multicast macaddr string
> +#
> +# Since 1.6
> +##
> +
> +{ 'type': 'RxFilterInfo',
> +  'data': {
> +    'name':               'str',
> +    'promiscuous':        'bool',
> +    'multicast':          'RxState',
> +    'unicast':            'RxState',
> +    'broadcast-allowed':  'bool',
> +    'multicast-overflow': 'bool',
> +    'unicast-overflow':   'bool',
> +    'main-mac':           'str',
> +    'vlan-table':         ['int'],
> +    'unicast-table':      ['str'],
> +    'multicast-table':    ['str'] }}
> +
> +##
> +# @query-rx-filter:
> +#
> +# Return rx-filter information for all nics (or for the given nic).
> +#
> +# @name: #optional net client name
> +#
> +# Returns: list of @RxFilterInfo for all nics (or for the given nic).
> +#          Returns an error if the given @name doesn't exist, or given
> +#          nic doesn't support rx-filter querying, or no net client
> +#          supports rx-filter querying
> +#
> +# Since: 1.6
> +##
> +{ 'command': 'query-rx-filter', 'data': { '*name': 'str' },
> +  'returns': ['RxFilterInfo'] }
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 8cea5e5..aa00a94 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -2997,3 +2997,66 @@ Example:
>  <- { "return": {} }
>  
>  EQMP
> +    {
> +        .name       = "query-rx-filter",
> +        .args_type  = "name:s?",
> +        .mhandler.cmd_new = qmp_marshal_input_query_rx_filter,
> +    },
> +
> +SQMP
> +query-rx-filter
> +---------------
> +
> +Show rx-filter information.
> +
> +Returns a json-array of rx-filter information for all nics (or for the
> +given nic), returning an error if the given nic doesn't exist, or
> +given nic doesn't support rx-filter querying, or no net client
> +supports rx-filter querying.
> +
> +The query will clear the event notification flag of each nic, then qemu
> +will start to emit event to QMP monitor.
> +
> +Each array entry contains the following:
> +
> +- "name": net client name (json-string)
> +- "promiscuous": promiscuous mode is enabled (json-bool)
> +- "multicast": multicast receive state (one of 'normal', 'none', 'all')
> +- "unicast": unicast receive state  (one of 'normal', 'none', 'all')
> +- "broadcast-allowed": allow to receive broadcast (json-bool)
> +- "multicast-overflow": multicast table is overflowed (json-bool)
> +- "unicast-overflow": unicast table is overflowed (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
> +- "multicast-table": a json-array of multicast macaddr string
> +
> +Example:
> +
> +-> { "execute": "query-rx-filter", "arguments": { "name": "vnet0" } }
> +<- { "return": [
> +        {
> +            "promiscuous": true,
> +            "name": "vnet0",
> +            "main-mac": "52:54:00:12:34:56",
> +            "unicast": "normal",
> +            "vlan-table": [
> +                4,
> +                0
> +            ],
> +            "unicast-table": [
> +            ],
> +            "multicast": "normal",
> +            "multicast-overflow": false,
> +            "unicast-overflow": false,
> +            "multicast-table": [
> +                "01:00:5e:00:00:01",
> +                "33:33:00:00:00:01",
> +                "33:33:ff:12:34:56"
> +            ],
> +            "broadcast-allowed": false
> +        }
> +      ]
> +   }
> +
> +EQMP