net: add support of mac-programming over macvtap in QEMU side

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

 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.

Michael S. Tsirkin: tweaked to enable events on start
Michael S. Tsirkin: fixed not to crash when no id
Michael S. Tsirkin: fold in patch:
   "additional fixes for mac-programming feature"
Amos Kong: always notify QMP client if mactable is changed
Amos Kong: return NULL list if no net client supports rx-filter query

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Amos Kong <akong@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 127 insertions, 6 deletions

diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 1ea95564a5..679f50c33a 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 +194,105 @@ 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) {
+        if (n->netclient_name) {
+            event_data = qobject_from_jsonf("{ 'name': %s, 'path': %s }",
+                                    n->netclient_name,
+                                    object_get_canonical_path(OBJECT(n->qdev)));
+        } else {
+            event_data = qobject_from_jsonf("{ 'path': %s }",
+                                    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, *entry;
+    intList *int_list, *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);
+
+    str_list = NULL;
+    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;
+
+    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;
+            }
+        }
+    }
+    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 +521,7 @@ 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 +544,8 @@ 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 +591,7 @@ 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 +600,8 @@ 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;
     }
 
@@ -512,19 +619,19 @@ static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
                    sizeof(mac_data.entries));
     mac_data.entries = ldl_p(&mac_data.entries);
     if (s != sizeof(mac_data.entries)) {
-        return VIRTIO_NET_ERR;
+        goto error;
     }
     iov_discard_front(&iov, &iov_cnt, s);
 
     if (mac_data.entries * ETH_ALEN > iov_size(iov, iov_cnt)) {
-        return VIRTIO_NET_ERR;
+        goto error;
     }
 
     if (mac_data.entries <= MAC_TABLE_ENTRIES) {
         s = iov_to_buf(iov, iov_cnt, 0, n->mac_table.macs,
                        mac_data.entries * ETH_ALEN);
         if (s != mac_data.entries * ETH_ALEN) {
-            return VIRTIO_NET_ERR;
+            goto error;
         }
         n->mac_table.in_use += mac_data.entries;
     } else {
@@ -539,27 +646,33 @@ static int virtio_net_handle_mac(VirtIONet *n, uint8_t cmd,
                    sizeof(mac_data.entries));
     mac_data.entries = ldl_p(&mac_data.entries);
     if (s != sizeof(mac_data.entries)) {
-        return VIRTIO_NET_ERR;
+        goto error;
     }
 
     iov_discard_front(&iov, &iov_cnt, s);
 
     if (mac_data.entries * ETH_ALEN != iov_size(iov, iov_cnt)) {
-        return VIRTIO_NET_ERR;
+        goto error;
     }
 
     if (n->mac_table.in_use + mac_data.entries <= MAC_TABLE_ENTRIES) {
         s = iov_to_buf(iov, iov_cnt, 0, n->mac_table.macs,
                        mac_data.entries * ETH_ALEN);
         if (s != mac_data.entries * ETH_ALEN) {
-            return VIRTIO_NET_ERR;
+            goto error;
         }
         n->mac_table.in_use += mac_data.entries;
     } else {
         n->mac_table.multi_overflow = 1;
     }
 
+    rxfilter_notify(nc);
+
     return VIRTIO_NET_OK;
+
+error:
+    rxfilter_notify(nc);
+    return VIRTIO_NET_ERR;
 }
 
 static int virtio_net_handle_vlan_table(VirtIONet *n, uint8_t cmd,
@@ -567,6 +680,7 @@ 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 +698,8 @@ 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 +1428,7 @@ 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)
@@ -1373,6 +1490,7 @@ static int virtio_net_device_init(VirtIODevice *vdev)
 
     DeviceState *qdev = DEVICE(vdev);
     VirtIONet *n = VIRTIO_NET(vdev);
+    NetClientState *nc;
 
     virtio_init(VIRTIO_DEVICE(n), "virtio-net", VIRTIO_ID_NET,
                                   n->config_size);
@@ -1439,6 +1557,9 @@ static int virtio_net_device_init(VirtIODevice *vdev)
 
     n->vlans = g_malloc0(MAX_VLAN >> 3);
 
+    nc = qemu_get_queue(n->nic);
+    nc->rxfilter_notify_enabled = 1;
+
     n->qdev = qdev;
     register_savevm(qdev, "virtio-net", -1, VIRTIO_NET_VM_VERSION,
                     virtio_net_save, virtio_net_load, n);