Wire up the interface backend options

Pass the user-specified tun path down when creating tap device
when called from the qemu driver.

Also honor the vhost device path specified by user.

src/bhyve/bhyve_command.c

@@ -72,7 +72,7 @@ bhyveBuildNetArgStr(const virDomainDef *def,
 
     if (!dryRun) {
         if (virNetDevTapCreateInBridgePort(brname, &net->ifname, &net->mac,
-                                           def->uuid, NULL, 0,
+                                           def->uuid, NULL, NULL, 0,
                                            virDomainNetGetActualVirtPortProfile(net),
                                            virDomainNetGetActualVlan(net),
                                            VIR_NETDEV_TAP_CREATE_IFUP | VIR_NETDEV_TAP_CREATE_PERSIST) < 0) {

src/bhyve/bhyve_process.c

@@ -82,7 +82,7 @@ bhyveNetCleanup(virDomainObjPtr vm)
                 ignore_value(virNetDevBridgeRemovePort(
                                 virDomainNetGetActualBridgeName(net),
                                 net->ifname));
-                ignore_value(virNetDevTapDelete(net->ifname));
+                ignore_value(virNetDevTapDelete(net->ifname, NULL));
             }
         }
     }

src/network/bridge_driver.c

@@ -1991,7 +1991,7 @@ networkStartNetworkVirtual(virNetworkDriverStatePtr driver,
         /* Keep tun fd open and interface up to allow for IPv6 DAD to happen */
         if (virNetDevTapCreateInBridgePort(network->def->bridge,
                                            &macTapIfName, &network->def->mac,
-                                           NULL, &tapfd, 1, NULL, NULL,
+                                           NULL, NULL, &tapfd, 1, NULL, NULL,
                                            VIR_NETDEV_TAP_CREATE_USE_MAC_FOR_BRIDGE |
                                            VIR_NETDEV_TAP_CREATE_IFUP |
                                            VIR_NETDEV_TAP_CREATE_PERSIST) < 0) {
@@ -2117,7 +2117,7 @@ networkStartNetworkVirtual(virNetworkDriverStatePtr driver,
 
     if (macTapIfName) {
         VIR_FORCE_CLOSE(tapfd);
-        ignore_value(virNetDevTapDelete(macTapIfName));
+        ignore_value(virNetDevTapDelete(macTapIfName, NULL));
         VIR_FREE(macTapIfName);
     }
 
@@ -2156,7 +2156,7 @@ static int networkShutdownNetworkVirtual(virNetworkDriverStatePtr driver ATTRIBU
     if (network->def->mac_specified) {
         char *macTapIfName = networkBridgeDummyNicName(network->def->bridge);
         if (macTapIfName) {
-            ignore_value(virNetDevTapDelete(macTapIfName));
+            ignore_value(virNetDevTapDelete(macTapIfName, NULL));
             VIR_FREE(macTapIfName);
         }
     }

src/qemu/qemu_command.c

@@ -290,6 +290,10 @@ qemuNetworkIfaceConnect(virDomainDefPtr def,
     bool template_ifname = false;
     int actualType = virDomainNetGetActualType(net);
     virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
+    const char *tunpath = "/dev/net/tun";
+
+    if (net->backend.tap)
+        tunpath = net->backend.tap;
 
     if (actualType == VIR_DOMAIN_NET_TYPE_NETWORK) {
         bool fail = false;
@@ -338,18 +342,18 @@ qemuNetworkIfaceConnect(virDomainDefPtr def,
 
     if (cfg->privileged) {
         if (virNetDevTapCreateInBridgePort(brname, &net->ifname, &net->mac,
-                                           def->uuid, tapfd, *tapfdSize,
+                                           def->uuid, tunpath, tapfd, *tapfdSize,
                                            virDomainNetGetActualVirtPortProfile(net),
                                            virDomainNetGetActualVlan(net),
                                            tap_create_flags) < 0) {
-            virDomainAuditNetDevice(def, net, "/dev/net/tun", false);
+            virDomainAuditNetDevice(def, net, tunpath, false);
             goto cleanup;
         }
     } else {
         if (qemuCreateInBridgePortWithHelper(cfg, brname,
                                              &net->ifname,
                                              tapfd, tap_create_flags) < 0) {
-            virDomainAuditNetDevice(def, net, "/dev/net/tun", false);
+            virDomainAuditNetDevice(def, net, tunpath, false);
             goto cleanup;
         }
         /* qemuCreateInBridgePortWithHelper can only create a single FD */
@@ -359,7 +363,7 @@ qemuNetworkIfaceConnect(virDomainDefPtr def,
         }
     }
 
-    virDomainAuditNetDevice(def, net, "/dev/net/tun", true);
+    virDomainAuditNetDevice(def, net, tunpath, true);
 
     if (cfg->macFilter &&
         ebtablesAddForwardAllowIn(driver->ebtables,
@@ -443,6 +447,10 @@ qemuOpenVhostNet(virDomainDefPtr def,
                  int *vhostfdSize)
 {
     size_t i;
+    const char *vhostnet_path = net->backend.vhost;
+
+    if (!vhostnet_path)
+        vhostnet_path = "/dev/vhost-net";
 
     /* If running a plain QEMU guest, or
      * if the config says explicitly to not use vhost, return now*/
@@ -480,13 +488,13 @@ qemuOpenVhostNet(virDomainDefPtr def,
     }
 
     for (i = 0; i < *vhostfdSize; i++) {
-        vhostfd[i] = open("/dev/vhost-net", O_RDWR);
+        vhostfd[i] = open(vhostnet_path, O_RDWR);
 
         /* If the config says explicitly to use vhost and we couldn't open it,
          * report an error.
          */
         if (vhostfd[i] < 0) {
-            virDomainAuditNetDevice(def, net, "/dev/vhost-net", false);
+            virDomainAuditNetDevice(def, net, vhostnet_path, false);
             if (net->driver.virtio.name == VIR_DOMAIN_NET_BACKEND_TYPE_VHOST) {
                 virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                                "%s", _("vhost-net was requested for an interface, "
@@ -499,7 +507,7 @@ qemuOpenVhostNet(virDomainDefPtr def,
             break;
         }
     }
-    virDomainAuditNetDevice(def, net, "/dev/vhost-net", *vhostfdSize);
+    virDomainAuditNetDevice(def, net, vhostnet_path, *vhostfdSize);
     return 0;
 
  error:

src/qemu/qemu_process.c

@@ -4866,7 +4866,7 @@ void qemuProcessStop(virQEMUDriverPtr driver,
         case VIR_DOMAIN_NET_TYPE_NETWORK:
 #ifdef VIR_NETDEV_TAP_REQUIRE_MANUAL_CLEANUP
             if (!(vport && vport->virtPortType == VIR_NETDEV_VPORT_PROFILE_OPENVSWITCH))
-                ignore_value(virNetDevTapDelete(net->ifname));
+                ignore_value(virNetDevTapDelete(net->ifname, net->backend.tap));
 #endif
             break;
         }

src/uml/uml_conf.c

@@ -124,7 +124,7 @@ umlConnectTapDevice(virConnectPtr conn,
     }
 
     if (virNetDevTapCreateInBridgePort(bridge, &net->ifname, &net->mac,
-                                       vm->uuid, &tapfd, 1,
+                                       vm->uuid, net->backend.tap, &tapfd, 1,
                                        virDomainNetGetActualVirtPortProfile(net),
                                        virDomainNetGetActualVlan(net),
                                        VIR_NETDEV_TAP_CREATE_IFUP |

src/uml/uml_driver.c

@@ -1032,7 +1032,8 @@ static void umlCleanupTapDevices(virDomainObjPtr vm)
             def->type != VIR_DOMAIN_NET_TYPE_NETWORK)
             continue;
 
-        ignore_value(virNetDevTapDelete(def->ifname));
+        ignore_value(virNetDevTapDelete(def->ifname,
+                                        def->backend.tap));
     }
 }
 

src/util/virnetdevtap.c

@@ -216,6 +216,7 @@ virNetDevProbeVnetHdr(int tapfd)
 /**
  * virNetDevTapCreate:
  * @ifname: the interface name
+ * @tunpath: path to the tun device (if NULL, /dev/net/tun is used)
  * @tapfds: array of file descriptors return value for the new tap device
  * @tapfdSize: number of file descriptors in @tapfd
  * @flags: OR of virNetDevTapCreateFlags. Only one flag is recognized:
@@ -233,6 +234,7 @@ virNetDevProbeVnetHdr(int tapfd)
  * Returns 0 in case of success or -1 on failure.
  */
 int virNetDevTapCreate(char **ifname,
+                       const char *tunpath,
                        int *tapfd,
                        int tapfdSize,
                        unsigned int flags)
@@ -242,11 +244,15 @@ int virNetDevTapCreate(char **ifname,
     int ret = -1;
     int fd;
 
+    if (!tunpath)
+        tunpath = "/dev/net/tun";
+
     memset(&ifr, 0, sizeof(ifr));
     for (i = 0; i < tapfdSize; i++) {
-        if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
-            virReportSystemError(errno, "%s",
-                                 _("Unable to open /dev/net/tun, is tun module loaded?"));
+        if ((fd = open(tunpath, O_RDWR)) < 0) {
+            virReportSystemError(errno,
+                                 _("Unable to open %s, is tun module loaded?"),
+                                 tunpath);
             goto cleanup;
         }
 
@@ -316,15 +322,20 @@ int virNetDevTapCreate(char **ifname,
 }
 
 
-int virNetDevTapDelete(const char *ifname)
+int virNetDevTapDelete(const char *ifname,
+                       const char *tunpath)
 {
     struct ifreq try;
     int fd;
     int ret = -1;
 
-    if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
-        virReportSystemError(errno, "%s",
-                             _("Unable to open /dev/net/tun, is tun module loaded?"));
+    if (!tunpath)
+        tunpath = "/dev/net/tun";
+
+    if ((fd = open(tunpath, O_RDWR)) < 0) {
+        virReportSystemError(errno,
+                             _("Unable to open %s, is tun module loaded?"),
+                             tunpath);
         return -1;
     }
 
@@ -358,6 +369,7 @@ int virNetDevTapDelete(const char *ifname)
 }
 #elif defined(SIOCIFCREATE2) && defined(SIOCIFDESTROY) && defined(IF_MAXUNIT)
 int virNetDevTapCreate(char **ifname,
+                       const char *tunpath ATTRIBUTE_UNUSED,
                        int *tapfd,
                        int tapfdSize,
                        unsigned int flags ATTRIBUTE_UNUSED)
@@ -444,7 +456,8 @@ int virNetDevTapCreate(char **ifname,
     return ret;
 }
 
-int virNetDevTapDelete(const char *ifname)
+int virNetDevTapDelete(const char *ifname,
+                       const char *tunpath ATTRIBUTE_UNUSED)
 {
     int s;
     struct ifreq ifr;
@@ -468,6 +481,7 @@ int virNetDevTapDelete(const char *ifname)
 
 #else
 int virNetDevTapCreate(char **ifname ATTRIBUTE_UNUSED,
+                       const char *tunpath ATTRIBUTE_UNUSED,
                        int *tapfd ATTRIBUTE_UNUSED,
                        int tapfdSize ATTRIBUTE_UNUSED,
                        unsigned int flags ATTRIBUTE_UNUSED)
@@ -476,7 +490,8 @@ int virNetDevTapCreate(char **ifname ATTRIBUTE_UNUSED,
                          _("Unable to create TAP devices on this platform"));
     return -1;
 }
-int virNetDevTapDelete(const char *ifname ATTRIBUTE_UNUSED)
+int virNetDevTapDelete(const char *ifname ATTRIBUTE_UNUSED,
+                       const char *tunpath ATTRIBUTE_UNUSED)
 {
     virReportSystemError(ENOSYS, "%s",
                          _("Unable to delete TAP devices on this platform"));
@@ -490,6 +505,7 @@ int virNetDevTapDelete(const char *ifname ATTRIBUTE_UNUSED)
  * @brname: the bridge name
  * @ifname: the interface name (or name template)
  * @macaddr: desired MAC address
+ * @tunpath: path to the tun device (if NULL, /dev/net/tun is used)
  * @tapfd: array of file descriptor return value for the new tap device
  * @tapfdSize: number of file descriptors in @tapfd
  * @virtPortProfile: bridge/port specific configuration
@@ -518,6 +534,7 @@ int virNetDevTapCreateInBridgePort(const char *brname,
                                    char **ifname,
                                    const virMacAddr *macaddr,
                                    const unsigned char *vmuuid,
+                                   const char *tunpath,
                                    int *tapfd,
                                    int tapfdSize,
                                    virNetDevVPortProfilePtr virtPortProfile,
@@ -528,7 +545,7 @@ int virNetDevTapCreateInBridgePort(const char *brname,
     char macaddrstr[VIR_MAC_STRING_BUFLEN];
     size_t i;
 
-    if (virNetDevTapCreate(ifname, tapfd, tapfdSize, flags) < 0)
+    if (virNetDevTapCreate(ifname, tunpath, tapfd, tapfdSize, flags) < 0)
         return -1;
 
     /* We need to set the interface MAC before adding it

src/util/virnetdevtap.h

@@ -34,12 +34,14 @@
 # endif
 
 int virNetDevTapCreate(char **ifname,
+                       const char *tunpath,
                        int *tapfd,
                        int tapfdSize,
                        unsigned int flags)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
 
-int virNetDevTapDelete(const char *ifname)
+int virNetDevTapDelete(const char *ifname,
+                       const char *tunpath)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
 
 int virNetDevTapGetName(int tapfd, char **ifname)
@@ -64,6 +66,7 @@ int virNetDevTapCreateInBridgePort(const char *brname,
                                    char **ifname,
                                    const virMacAddr *macaddr,
                                    const unsigned char *vmuuid,
+                                   const char *tunpath,
                                    int *tapfd,
                                    int tapfdSize,
                                    virNetDevVPortProfilePtr virtPortProfile,