[libvirt] [PATCH v7] autocreate tap device for VIR_DOMAIN_NET_TYPE_ETHERNET

Vasiliy Tolstov v.tolstov at selfip.ru
Fri Jul 24 09:10:41 UTC 2015


If a user specify ehernet device create it via libvirt and run
script if it provided. After this commit user does not need to
run external script to create tap device or add root to qemu
process.

Signed-off-by: Vasiliy Tolstov <v.tolstov at selfip.ru>
---
 src/qemu/qemu_command.c | 143 +++++++++++++++++++++++++++++++-----------------
 src/qemu/qemu_hotplug.c |  13 ++---
 src/qemu/qemu_process.c |   6 ++
 3 files changed, 102 insertions(+), 60 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 3886b4f..c4d1fde 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -332,10 +332,39 @@ static int qemuCreateInBridgePortWithHelper(virQEMUDriverConfigPtr cfg,
     return *tapfd < 0 ? -1 : 0;
 }
 
+/**
+ * qemuExecuteEthernetScript:
+ * @ifname: the interface name
+ * @script: the script name
+ *
+ * This function executes script for new tap device created by libvirt.
+ * Returns 0 in case of success or -1 on failure
+ */
+static int
+qemuExecuteEthernetScript(const char *ifname, const char *script)
+{
+    virCommandPtr cmd;
+    int ret;
+
+    cmd = virCommandNew(script);
+    virCommandAddArgFormat(cmd, "%s", ifname);
+    virCommandClearCaps(cmd);
+#ifdef CAP_NET_ADMIN
+    virCommandAllowCap(cmd, CAP_NET_ADMIN);
+#endif
+    virCommandAddEnvPassCommon(cmd);
+
+    ret = virCommandRun(cmd, NULL);
+
+    virCommandFree(cmd);
+    return ret;
+}
+
 /* qemuNetworkIfaceConnect - *only* called if actualType is
- * VIR_DOMAIN_NET_TYPE_NETWORK or VIR_DOMAIN_NET_TYPE_BRIDGE (i.e. if
- * the connection is made with a tap device connecting to a bridge
- * device)
+ * VIR_DOMAIN_NET_TYPE_NETWORK, VIR_DOMAIN_NET_TYPE_BRIDGE
+ * VIR_DOMAIN_NET_TYPE_ETHERNET (i.e. if the connection is
+ * made with a tap device connecting to a bridge device or
+ * use plain tap device)
  */
 int
 qemuNetworkIfaceConnect(virDomainDefPtr def,
@@ -351,6 +380,7 @@ qemuNetworkIfaceConnect(virDomainDefPtr def,
     bool template_ifname = false;
     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
     const char *tunpath = "/dev/net/tun";
+    virMacAddr tapmac;
 
     if (net->backend.tap) {
         tunpath = net->backend.tap;
@@ -361,11 +391,6 @@ qemuNetworkIfaceConnect(virDomainDefPtr def,
         }
     }
 
-    if (!(brname = virDomainNetGetActualBridgeName(net))) {
-        virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("Missing bridge name"));
-        goto cleanup;
-    }
-
     if (!net->ifname ||
         STRPREFIX(net->ifname, VIR_NET_GENERATED_PREFIX) ||
         strchr(net->ifname, '%')) {
@@ -381,40 +406,66 @@ qemuNetworkIfaceConnect(virDomainDefPtr def,
         tap_create_flags |= VIR_NETDEV_TAP_CREATE_VNET_HDR;
     }
 
-    if (cfg->privileged) {
-        if (virNetDevTapCreateInBridgePort(brname, &net->ifname, &net->mac,
-                                           def->uuid, tunpath, tapfd, *tapfdSize,
-                                           virDomainNetGetActualVirtPortProfile(net),
-                                           virDomainNetGetActualVlan(net),
-                                           tap_create_flags) < 0) {
+    if (virDomainNetGetActualType(net) == VIR_DOMAIN_NET_TYPE_ETHERNET) {
+        if (virNetDevTapCreate(&net->ifname, tunpath, tapfd, *tapfdSize,
+                               tap_create_flags) < 0) {
             virDomainAuditNetDevice(def, net, tunpath, false);
             goto cleanup;
         }
-        if (virDomainNetGetActualBridgeMACTableManager(net)
-            == VIR_NETWORK_BRIDGE_MAC_TABLE_MANAGER_LIBVIRT) {
-            /* libvirt is managing the FDB of the bridge this device
-             * is attaching to, so we need to turn off learning and
-             * unicast_flood on the device to prevent the kernel from
-             * adding any FDB entries for it. We will add add an fdb
-             * entry ourselves (during qemuInterfaceStartDevices(),
-             * using the MAC address from the interface config.
-             */
-            if (virNetDevBridgePortSetLearning(brname, net->ifname, false) < 0)
-                goto cleanup;
-            if (virNetDevBridgePortSetUnicastFlood(brname, net->ifname, false) < 0)
+        virMacAddrSet(&tapmac, &net->mac);
+        tapmac.addr[0] = 0xFE;
+
+        if (virNetDevSetMAC(net->ifname, &tapmac) < 0)
+            goto cleanup;
+
+        if (virNetDevSetOnline(net->ifname, true) < 0)
+            goto cleanup;
+
+        if (net->script) {
+            if (qemuExecuteEthernetScript(net->ifname, net->script) < 0)
                 goto cleanup;
         }
     } else {
-        if (qemuCreateInBridgePortWithHelper(cfg, brname,
-                                             &net->ifname,
-                                             tapfd, tap_create_flags) < 0) {
-            virDomainAuditNetDevice(def, net, tunpath, false);
+        if (!(brname = virDomainNetGetActualBridgeName(net))) {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("Missing bridge name"));
             goto cleanup;
         }
-        /* qemuCreateInBridgePortWithHelper can only create a single FD */
-        if (*tapfdSize > 1) {
-            VIR_WARN("Ignoring multiqueue network request");
-            *tapfdSize = 1;
+
+        if (cfg->privileged) {
+            if (virNetDevTapCreateInBridgePort(brname, &net->ifname, &net->mac,
+                                               def->uuid, tunpath, tapfd, *tapfdSize,
+                                               virDomainNetGetActualVirtPortProfile(net),
+                                               virDomainNetGetActualVlan(net),
+                                               tap_create_flags) < 0) {
+                virDomainAuditNetDevice(def, net, tunpath, false);
+                goto cleanup;
+            }
+            if (virDomainNetGetActualBridgeMACTableManager(net)
+                == VIR_NETWORK_BRIDGE_MAC_TABLE_MANAGER_LIBVIRT) {
+                /* libvirt is managing the FDB of the bridge this device
+                 * is attaching to, so we need to turn off learning and
+                 * unicast_flood on the device to prevent the kernel from
+                 * adding any FDB entries for it. We will add add an fdb
+                 * entry ourselves (during qemuInterfaceStartDevices(),
+                 * using the MAC address from the interface config.
+                 */
+                if (virNetDevBridgePortSetLearning(brname, net->ifname, false) < 0)
+                    goto cleanup;
+                if (virNetDevBridgePortSetUnicastFlood(brname, net->ifname, false) < 0)
+                    goto cleanup;
+            }
+        } else {
+            if (qemuCreateInBridgePortWithHelper(cfg, brname,
+                                                 &net->ifname,
+                                                 tapfd, tap_create_flags) < 0) {
+                virDomainAuditNetDevice(def, net, tunpath, false);
+                goto cleanup;
+            }
+            /* qemuCreateInBridgePortWithHelper can only create a single FD */
+            if (*tapfdSize > 1) {
+                VIR_WARN("Ignoring multiqueue network request");
+                *tapfdSize = 1;
+            }
         }
     }
 
@@ -5221,6 +5272,7 @@ qemuBuildHostNetStr(virDomainNetDefPtr net,
     case VIR_DOMAIN_NET_TYPE_BRIDGE:
     case VIR_DOMAIN_NET_TYPE_NETWORK:
     case VIR_DOMAIN_NET_TYPE_DIRECT:
+    case VIR_DOMAIN_NET_TYPE_ETHERNET:
         virBufferAsprintf(&buf, "tap%c", type_sep);
         /* for one tapfd 'fd=' shall be used,
          * for more than one 'fds=' is the right choice */
@@ -5238,20 +5290,6 @@ qemuBuildHostNetStr(virDomainNetDefPtr net,
         is_tap = true;
         break;
 
-    case VIR_DOMAIN_NET_TYPE_ETHERNET:
-        virBufferAddLit(&buf, "tap");
-        if (net->ifname) {
-            virBufferAsprintf(&buf, "%cifname=%s", type_sep, net->ifname);
-            type_sep = ',';
-        }
-        if (net->script) {
-            virBufferAsprintf(&buf, "%cscript=%s", type_sep,
-                              net->script);
-            type_sep = ',';
-        }
-        is_tap = true;
-        break;
-
     case VIR_DOMAIN_NET_TYPE_CLIENT:
        virBufferAsprintf(&buf, "socket%cconnect=%s:%d",
                          type_sep,
@@ -8226,7 +8264,8 @@ qemuBuildInterfaceCommandLine(virCommandPtr cmd,
     /* Currently nothing besides TAP devices supports multiqueue. */
     if (net->driver.virtio.queues > 0 &&
         !(actualType == VIR_DOMAIN_NET_TYPE_NETWORK ||
-          actualType == VIR_DOMAIN_NET_TYPE_BRIDGE)) {
+          actualType == VIR_DOMAIN_NET_TYPE_BRIDGE ||
+          actualType == VIR_DOMAIN_NET_TYPE_ETHERNET)) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                        _("Multiqueue network is not supported for: %s"),
                        virDomainNetTypeToString(actualType));
@@ -8235,7 +8274,8 @@ qemuBuildInterfaceCommandLine(virCommandPtr cmd,
 
     if (net->backend.tap &&
         !(actualType == VIR_DOMAIN_NET_TYPE_NETWORK ||
-          actualType == VIR_DOMAIN_NET_TYPE_BRIDGE)) {
+          actualType == VIR_DOMAIN_NET_TYPE_BRIDGE ||
+          actualType == VIR_DOMAIN_NET_TYPE_ETHERNET)) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                        _("Custom tap device path is not supported for: %s"),
                        virDomainNetTypeToString(actualType));
@@ -8245,7 +8285,8 @@ qemuBuildInterfaceCommandLine(virCommandPtr cmd,
     cfg = virQEMUDriverGetConfig(driver);
 
     if (actualType == VIR_DOMAIN_NET_TYPE_NETWORK ||
-        actualType == VIR_DOMAIN_NET_TYPE_BRIDGE) {
+        actualType == VIR_DOMAIN_NET_TYPE_BRIDGE ||
+        actualType == VIR_DOMAIN_NET_TYPE_ETHERNET) {
         tapfdSize = net->driver.virtio.queues;
         if (!tapfdSize)
             tapfdSize = 1;
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index cc86a3b..21ea3fd 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -908,7 +908,8 @@ int qemuDomainAttachNetDevice(virConnectPtr conn,
     /* Currently nothing besides TAP devices supports multiqueue. */
     if (net->driver.virtio.queues > 0 &&
         !(actualType == VIR_DOMAIN_NET_TYPE_NETWORK ||
-          actualType == VIR_DOMAIN_NET_TYPE_BRIDGE)) {
+          actualType == VIR_DOMAIN_NET_TYPE_BRIDGE ||
+          actualType == VIR_DOMAIN_NET_TYPE_ETHERNET)) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                        _("Multiqueue network is not supported for: %s"),
                        virDomainNetTypeToString(actualType));
@@ -916,7 +917,8 @@ int qemuDomainAttachNetDevice(virConnectPtr conn,
     }
 
     if (actualType == VIR_DOMAIN_NET_TYPE_BRIDGE ||
-        actualType == VIR_DOMAIN_NET_TYPE_NETWORK) {
+        actualType == VIR_DOMAIN_NET_TYPE_NETWORK ||
+        actualType == VIR_DOMAIN_NET_TYPE_ETHERNET) {
         tapfdSize = vhostfdSize = net->driver.virtio.queues;
         if (!tapfdSize)
             tapfdSize = vhostfdSize = 1;
@@ -947,13 +949,6 @@ int qemuDomainAttachNetDevice(virConnectPtr conn,
         iface_connected = true;
         if (qemuOpenVhostNet(vm->def, net, priv->qemuCaps, vhostfd, &vhostfdSize) < 0)
             goto cleanup;
-    } else if (actualType == VIR_DOMAIN_NET_TYPE_ETHERNET) {
-        vhostfdSize = 1;
-        if (VIR_ALLOC(vhostfd) < 0)
-            goto cleanup;
-        *vhostfd = -1;
-        if (qemuOpenVhostNet(vm->def, net, priv->qemuCaps, vhostfd, &vhostfdSize) < 0)
-            goto cleanup;
     }
 
     /* Set device online immediately */
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 64ee049..d866e44 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -5205,6 +5205,12 @@ void qemuProcessStop(virQEMUDriverPtr driver,
                              cfg->stateDir));
             VIR_FREE(net->ifname);
             break;
+        case VIR_DOMAIN_NET_TYPE_ETHERNET:
+            if (net->ifname) {
+                ignore_value(virNetDevTapDelete(net->ifname, net->backend.tap));
+                VIR_FREE(net->ifname);
+            }
+            break;
         case VIR_DOMAIN_NET_TYPE_BRIDGE:
         case VIR_DOMAIN_NET_TYPE_NETWORK:
 #ifdef VIR_NETDEV_TAP_REQUIRE_MANUAL_CLEANUP
-- 
2.3.3




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