qemu: simplify interface fd handling in monitor

With only a single caller to these two monitor commands, I
didn't need to wrap a new WithFds version, but just change
the command itself.

* src/qemu/qemu_monitor.h (qemuMonitorAddNetdev)
(qemuMonitorAddHostNetwork): Add parameters.
* src/qemu/qemu_monitor.c (qemuMonitorAddNetdev)
(qemuMonitorAddHostNetwork): Add support for fd passing.
* src/qemu/qemu_hotplug.c (qemuDomainAttachNetDevice): Use it to
simplify code.

src/qemu/qemu_hotplug.c

@@ -611,63 +611,39 @@ int qemuDomainAttachNetDevice(virConnectPtr conn,
     if (tapfd != -1) {
         if (virAsprintf(&tapfd_name, "fd-%s", net->info.alias) < 0)
             goto no_memory;
-
-        qemuDomainObjEnterMonitorWithDriver(driver, vm);
-        if (qemuMonitorSendFileHandle(priv->mon, tapfd_name, tapfd) < 0) {
-            qemuDomainObjExitMonitorWithDriver(driver, vm);
-            goto cleanup;
-        }
-        qemuDomainObjExitMonitorWithDriver(driver, vm);
-
-        if (!virDomainObjIsActive(vm)) {
-            qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                            _("guest unexpectedly quit"));
-            goto cleanup;
-        }
     }
 
     if (vhostfd != -1) {
         if (virAsprintf(&vhostfd_name, "vhostfd-%s", net->info.alias) < 0)
             goto no_memory;
-
-        qemuDomainObjEnterMonitorWithDriver(driver, vm);
-        if (qemuMonitorSendFileHandle(priv->mon, vhostfd_name, vhostfd) < 0) {
-            qemuDomainObjExitMonitorWithDriver(driver, vm);
-            goto try_tapfd_close;
-        }
-        qemuDomainObjExitMonitorWithDriver(driver, vm);
-
-        if (!virDomainObjIsActive(vm)) {
-            qemuReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                            _("guest unexpectedly quit"));
-            goto cleanup;
-        }
     }
 
     if (qemuCapsGet(qemuCaps, QEMU_CAPS_NETDEV) &&
         qemuCapsGet(qemuCaps, QEMU_CAPS_DEVICE)) {
         if (!(netstr = qemuBuildHostNetStr(net, ',',
                                            -1, tapfd_name, vhostfd_name)))
-            goto try_tapfd_close;
+            goto cleanup;
     } else {
         if (!(netstr = qemuBuildHostNetStr(net, ' ',
                                            vlan, tapfd_name, vhostfd_name)))
-            goto try_tapfd_close;
+            goto cleanup;
     }
 
     qemuDomainObjEnterMonitorWithDriver(driver, vm);
     if (qemuCapsGet(qemuCaps, QEMU_CAPS_NETDEV) &&
         qemuCapsGet(qemuCaps, QEMU_CAPS_DEVICE)) {
-        if (qemuMonitorAddNetdev(priv->mon, netstr) < 0) {
+        if (qemuMonitorAddNetdev(priv->mon, netstr, tapfd, tapfd_name,
+                                 vhostfd, vhostfd_name) < 0) {
             qemuDomainObjExitMonitorWithDriver(driver, vm);
             qemuAuditNet(vm, NULL, net, "attach", false);
-            goto try_tapfd_close;
+            goto cleanup;
         }
     } else {
-        if (qemuMonitorAddHostNetwork(priv->mon, netstr) < 0) {
+        if (qemuMonitorAddHostNetwork(priv->mon, netstr, tapfd, tapfd_name,
+                                      vhostfd, vhostfd_name) < 0) {
             qemuDomainObjExitMonitorWithDriver(driver, vm);
             qemuAuditNet(vm, NULL, net, "attach", false);
-            goto try_tapfd_close;
+            goto cleanup;
         }
     }
     qemuDomainObjExitMonitorWithDriver(driver, vm);
@@ -765,23 +741,6 @@ try_remove:
     }
     goto cleanup;
 
-try_tapfd_close:
-    if (!virDomainObjIsActive(vm))
-        goto cleanup;
-
-    if (tapfd_name || vhostfd_name) {
-        qemuDomainObjEnterMonitorWithDriver(driver, vm);
-        if (tapfd_name &&
-            qemuMonitorCloseFileHandle(priv->mon, tapfd_name) < 0)
-            VIR_WARN("Failed to close tapfd with '%s'", tapfd_name);
-        if (vhostfd_name &&
-            qemuMonitorCloseFileHandle(priv->mon, vhostfd_name) < 0)
-            VIR_WARN("Failed to close vhostfd with '%s'", vhostfd_name);
-        qemuDomainObjExitMonitorWithDriver(driver, vm);
-    }
-
-    goto cleanup;
-
 no_memory:
     virReportOOMError();
     goto cleanup;

src/qemu/qemu_monitor.c

@@ -1820,11 +1820,15 @@ int qemuMonitorCloseFileHandle(qemuMonitorPtr mon,
 
 
 int qemuMonitorAddHostNetwork(qemuMonitorPtr mon,
-                              const char *netstr)
+                              const char *netstr,
+                              int tapfd, const char *tapfd_name,
+                              int vhostfd, const char *vhostfd_name)
 {
-    int ret;
-    VIR_DEBUG("mon=%p netstr=%s",
-          mon, netstr);
+    int ret = -1;
+    VIR_DEBUG("mon=%p netstr=%s tapfd=%d tapfd_name=%s "
+              "vhostfd=%d vhostfd_name=%s",
+              mon, netstr, tapfd, NULLSTR(tapfd_name),
+              vhostfd, NULLSTR(vhostfd_name));
 
     if (!mon) {
         qemuReportError(VIR_ERR_INVALID_ARG, "%s",
@@ -1832,10 +1836,27 @@ int qemuMonitorAddHostNetwork(qemuMonitorPtr mon,
         return -1;
     }
 
+    if (tapfd >= 0 && qemuMonitorSendFileHandle(mon, tapfd_name, tapfd) < 0)
+        return -1;
+    if (vhostfd >= 0 &&
+        qemuMonitorSendFileHandle(mon, vhostfd_name, vhostfd) < 0) {
+        vhostfd = -1;
+        goto cleanup;
+    }
+
     if (mon->json)
         ret = qemuMonitorJSONAddHostNetwork(mon, netstr);
     else
         ret = qemuMonitorTextAddHostNetwork(mon, netstr);
+
+cleanup:
+    if (ret < 0) {
+        if (tapfd >= 0 && qemuMonitorCloseFileHandle(mon, tapfd_name) < 0)
+            VIR_WARN("failed to close device handle '%s'", tapfd_name);
+        if (vhostfd >= 0 && qemuMonitorCloseFileHandle(mon, vhostfd_name) < 0)
+            VIR_WARN("failed to close device handle '%s'", vhostfd_name);
+    }
+
     return ret;
 }
 
@@ -1863,11 +1884,15 @@ int qemuMonitorRemoveHostNetwork(qemuMonitorPtr mon,
 
 
 int qemuMonitorAddNetdev(qemuMonitorPtr mon,
-                         const char *netdevstr)
+                         const char *netdevstr,
+                         int tapfd, const char *tapfd_name,
+                         int vhostfd, const char *vhostfd_name)
 {
-    int ret;
-    VIR_DEBUG("mon=%p netdevstr=%s",
-          mon, netdevstr);
+    int ret = -1;
+    VIR_DEBUG("mon=%p netdevstr=%s tapfd=%d tapfd_name=%s "
+              "vhostfd=%d vhostfd_name=%s",
+              mon, netdevstr, tapfd, NULLSTR(tapfd_name),
+              vhostfd, NULLSTR(vhostfd_name));
 
     if (!mon) {
         qemuReportError(VIR_ERR_INVALID_ARG, "%s",
@@ -1875,14 +1900,30 @@ int qemuMonitorAddNetdev(qemuMonitorPtr mon,
         return -1;
     }
 
+    if (tapfd >= 0 && qemuMonitorSendFileHandle(mon, tapfd_name, tapfd) < 0)
+        return -1;
+    if (vhostfd >= 0 &&
+        qemuMonitorSendFileHandle(mon, vhostfd_name, vhostfd) < 0) {
+        vhostfd = -1;
+        goto cleanup;
+    }
+
     if (mon->json)
         ret = qemuMonitorJSONAddNetdev(mon, netdevstr);
     else
         ret = qemuMonitorTextAddNetdev(mon, netdevstr);
+
+cleanup:
+    if (ret < 0) {
+        if (tapfd >= 0 && qemuMonitorCloseFileHandle(mon, tapfd_name) < 0)
+            VIR_WARN("failed to close device handle '%s'", tapfd_name);
+        if (vhostfd >= 0 && qemuMonitorCloseFileHandle(mon, vhostfd_name) < 0)
+            VIR_WARN("failed to close device handle '%s'", vhostfd_name);
+    }
+
     return ret;
 }
 
-
 int qemuMonitorRemoveNetdev(qemuMonitorPtr mon,
                             const char *alias)
 {

src/qemu/qemu_monitor.h

@@ -352,14 +352,18 @@ int qemuMonitorCloseFileHandle(qemuMonitorPtr mon,
  * sendable item here
  */
 int qemuMonitorAddHostNetwork(qemuMonitorPtr mon,
-                              const char *netstr);
+                              const char *netstr,
+                              int tapfd, const char *tapfd_name,
+                              int vhostfd, const char *vhostfd_name);
 
 int qemuMonitorRemoveHostNetwork(qemuMonitorPtr mon,
                                  int vlan,
                                  const char *netname);
 
 int qemuMonitorAddNetdev(qemuMonitorPtr mon,
-                         const char *netdevstr);
+                         const char *netdevstr,
+                         int tapfd, const char *tapfd_name,
+                         int vhostfd, const char *vhostfd_name);
 
 int qemuMonitorRemoveNetdev(qemuMonitorPtr mon,
                             const char *alias);