qemu: Move opening of tap file descriptors for net devices into qemuBuildInterfaceConnect

Use the new infrastructure which stores the fds inside 'qemuFDPass'
objects in the private data.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Jonathon Jongsma <jjongsma@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/qemu/qemu_command.c

@@ -8683,6 +8683,7 @@ qemuInterfaceVhostuserConnect(virCommand *cmd,
 int
 qemuBuildInterfaceConnect(virDomainObj *vm,
                           virDomainNetDef *net,
+                          virNetDevVPortProfileOp vmop,
                           bool standalone)
 {
 
@@ -8690,19 +8691,33 @@ qemuBuildInterfaceConnect(virDomainObj *vm,
     virDomainNetType actualType = virDomainNetGetActualType(net);
     qemuDomainNetworkPrivate *netpriv = QEMU_DOMAIN_NETWORK_PRIVATE(net);
     VIR_AUTOCLOSE vdpafd = -1;
-    bool vhostfd = false;
+    bool vhostfd = false; /* also used to signal processing of tapfds */
+    size_t tapfdSize = net->driver.virtio.queues;
+    g_autofree int *tapfd = g_new0(int, tapfdSize + 1);
+
+    if (tapfdSize == 0)
+        tapfdSize = 1;
 
     switch (actualType) {
     case VIR_DOMAIN_NET_TYPE_NETWORK:
     case VIR_DOMAIN_NET_TYPE_BRIDGE:
         vhostfd = true;
+        if (qemuInterfaceBridgeConnect(vm->def, priv->driver, net,
+                                       tapfd, &tapfdSize) < 0)
+            return -1;
         break;
 
     case VIR_DOMAIN_NET_TYPE_DIRECT:
         vhostfd = true;
+        if (qemuInterfaceDirectConnect(vm->def, priv->driver, net,
+                                       tapfd, tapfdSize, vmop) < 0)
+            return -1;
         break;
 
     case VIR_DOMAIN_NET_TYPE_ETHERNET:
+        if (qemuInterfaceEthernetConnect(vm->def, priv->driver, net,
+                                         tapfd, tapfdSize) < 0)
+            return -1;
         vhostfd = true;
         break;
 
@@ -8728,6 +8743,29 @@ qemuBuildInterfaceConnect(virDomainObj *vm,
         break;
     }
 
+    /* 'vhostfd' is set to true in all cases when we need to process tapfds */
+    if (vhostfd) {
+        g_autofree char *prefix = g_strdup_printf("tapfd-%s", net->info.alias);
+        size_t i;
+
+        for (i = 0; i < tapfdSize; i++) {
+            g_autoptr(qemuFDPass) pass = qemuFDPassNewDirect(prefix, priv);
+            g_autofree char *suffix = g_strdup_printf("%zu", i);
+            int fd = tapfd[i]; /* we want to keep the array intact for security labeling*/
+
+            qemuFDPassAddFD(pass, &fd, suffix);
+            netpriv->tapfds = g_slist_prepend(netpriv->tapfds, g_steal_pointer(&pass));
+        }
+
+        netpriv->tapfds = g_slist_reverse(netpriv->tapfds);
+
+        for (i = 0; i < tapfdSize; i++) {
+            if (qemuSecuritySetTapFDLabel(priv->driver->securityManager,
+                                          vm->def, tapfd[i]) < 0)
+                return -1;
+        }
+    }
+
     if (vhostfd && !standalone) {
         if (qemuInterfaceOpenVhostNet(vm, net) < 0)
             return -1;
@@ -8768,54 +8806,14 @@ qemuBuildInterfaceCommandLine(virQEMUDriver *driver,
     if (qemuDomainValidateActualNetDef(net, qemuCaps) < 0)
         return -1;
 
-    if (qemuBuildInterfaceConnect(vm, net, standalone) < 0)
+    if (qemuBuildInterfaceConnect(vm, net, vmop, standalone) < 0)
         return -1;
 
     switch (actualType) {
     case VIR_DOMAIN_NET_TYPE_NETWORK:
     case VIR_DOMAIN_NET_TYPE_BRIDGE:
-        tapfdSize = net->driver.virtio.queues;
-        if (!tapfdSize)
-            tapfdSize = 1;
-
-        tapfd = g_new0(int, tapfdSize);
-        tapfdName = g_new0(char *, tapfdSize);
-
-        memset(tapfd, -1, tapfdSize * sizeof(tapfd[0]));
-
-        if (qemuInterfaceBridgeConnect(def, driver, net,
-                                       tapfd, &tapfdSize) < 0)
-            goto cleanup;
-        break;
-
     case VIR_DOMAIN_NET_TYPE_DIRECT:
-        tapfdSize = net->driver.virtio.queues;
-        if (!tapfdSize)
-            tapfdSize = 1;
-
-        tapfd = g_new0(int, tapfdSize);
-        tapfdName = g_new0(char *, tapfdSize);
-
-        memset(tapfd, -1, tapfdSize * sizeof(tapfd[0]));
-
-        if (qemuInterfaceDirectConnect(def, driver, net,
-                                       tapfd, tapfdSize, vmop) < 0)
-            goto cleanup;
-        break;
-
     case VIR_DOMAIN_NET_TYPE_ETHERNET:
-        tapfdSize = net->driver.virtio.queues;
-        if (!tapfdSize)
-            tapfdSize = 1;
-
-        tapfd = g_new0(int, tapfdSize);
-        tapfdName = g_new0(char *, tapfdSize);
-
-        memset(tapfd, -1, tapfdSize * sizeof(tapfd[0]));
-
-        if (qemuInterfaceEthernetConnect(def, driver, net,
-                                         tapfd, tapfdSize) < 0)
-            goto cleanup;
         break;
 
     case VIR_DOMAIN_NET_TYPE_HOSTDEV:

src/qemu/qemu_command.h

@@ -94,6 +94,7 @@ qemuBuildHostNetProps(virDomainNetDef *net,
 int
 qemuBuildInterfaceConnect(virDomainObj *vm,
                           virDomainNetDef *net,
+                          virNetDevVPortProfileOp vmop,
                           bool standalone);
 
 /* Current, best practice */

src/qemu/qemu_hotplug.c

@@ -1274,46 +1274,16 @@ qemuDomainAttachNetDevice(virQEMUDriver *driver,
      */
     VIR_APPEND_ELEMENT_COPY(vm->def->nets, vm->def->nnets, net);
 
-    if (qemuBuildInterfaceConnect(vm, net, false) < 0)
+    if (qemuBuildInterfaceConnect(vm, net, VIR_NETDEV_VPORT_PROFILE_OP_CREATE, false) < 0)
          return -1;
 
+    iface_connected = true;
+
     switch (actualType) {
     case VIR_DOMAIN_NET_TYPE_BRIDGE:
     case VIR_DOMAIN_NET_TYPE_NETWORK:
-        tapfdSize = net->driver.virtio.queues;
-        if (!tapfdSize)
-            tapfdSize = 1;
-        tapfd = g_new0(int, tapfdSize);
-        memset(tapfd, -1, sizeof(*tapfd) * tapfdSize);
-        if (qemuInterfaceBridgeConnect(vm->def, driver, net,
-                                       tapfd, &tapfdSize) < 0)
-            goto cleanup;
-        iface_connected = true;
-        break;
-
     case VIR_DOMAIN_NET_TYPE_DIRECT:
-        tapfdSize = net->driver.virtio.queues;
-        if (!tapfdSize)
-            tapfdSize = 1;
-        tapfd = g_new0(int, tapfdSize);
-        memset(tapfd, -1, sizeof(*tapfd) * tapfdSize);
-        if (qemuInterfaceDirectConnect(vm->def, driver, net,
-                                       tapfd, tapfdSize,
-                                       VIR_NETDEV_VPORT_PROFILE_OP_CREATE) < 0)
-            goto cleanup;
-        iface_connected = true;
-        break;
-
     case VIR_DOMAIN_NET_TYPE_ETHERNET:
-        tapfdSize = net->driver.virtio.queues;
-        if (!tapfdSize)
-            tapfdSize = 1;
-        tapfd = g_new0(int, tapfdSize);
-        memset(tapfd, -1, sizeof(*tapfd) * tapfdSize);
-        if (qemuInterfaceEthernetConnect(vm->def, driver, net,
-                                         tapfd, tapfdSize) < 0)
-            goto cleanup;
-        iface_connected = true;
         break;
 
     case VIR_DOMAIN_NET_TYPE_VHOSTUSER: