[PATCH 34/37] qemu: slirp: Pass FDs to qemu via qemuFDPass in the network private data

Peter Krempa pkrempa at redhat.com
Tue May 10 15:20:10 UTC 2022


Populate the 'slirpfd' qemuFDPass structure inside the private data for
passing the fd to qemu rather than using out-of-band variables.

Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---
 src/qemu/qemu_command.c | 27 +++++++++------------------
 src/qemu/qemu_command.h |  3 +--
 src/qemu/qemu_hotplug.c |  9 +++------
 src/qemu/qemu_slirp.c   |  8 +++++++-
 4 files changed, 20 insertions(+), 27 deletions(-)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 92b91b0a52..e48b59abbb 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -4186,8 +4186,7 @@ qemuBuildNicDevProps(virDomainDef *def,


 virJSONValue *
-qemuBuildHostNetProps(virDomainNetDef *net,
-                      const char *slirpfd)
+qemuBuildHostNetProps(virDomainNetDef *net)
 {
     virDomainNetType netType = virDomainNetGetActualType(net);
     size_t i;
@@ -4302,9 +4301,11 @@ qemuBuildHostNetProps(virDomainNetDef *net,
         break;

     case VIR_DOMAIN_NET_TYPE_USER:
-        if (slirpfd) {
-            if (virJSONValueObjectAdd(&netprops, "s:type", "socket", NULL) < 0 ||
-                virJSONValueObjectAppendString(netprops, "fd", slirpfd) < 0)
+        if (netpriv->slirpfd) {
+            if (virJSONValueObjectAdd(&netprops,
+                                      "s:type", "socket",
+                                      "s:fd", qemuFDPassGetPath(netpriv->slirpfd),
+                                      NULL) < 0)
                 return NULL;
         } else {
             if (virJSONValueObjectAdd(&netprops, "s:type", "user", NULL) < 0)
@@ -8760,11 +8761,9 @@ qemuBuildInterfaceCommandLine(virQEMUDriver *driver,
     int ret = -1;
     g_autoptr(virJSONValue) nicprops = NULL;
     g_autofree char *nic = NULL;
-    g_autofree char *slirpfdName = NULL;
     virDomainNetType actualType = virDomainNetGetActualType(net);
     const virNetDevBandwidth *actualBandwidth;
     bool requireNicdev = false;
-    qemuSlirp *slirp;
     g_autoptr(virJSONValue) hostnetprops = NULL;
     qemuDomainNetworkPrivate *netpriv = QEMU_DOMAIN_NETWORK_PRIVATE(net);
     GSList *n;
@@ -8890,14 +8889,6 @@ qemuBuildInterfaceCommandLine(virQEMUDriver *driver,
         virNetDevSetMTU(net->ifname, net->mtu) < 0)
         goto cleanup;

-    slirp = QEMU_DOMAIN_NETWORK_PRIVATE(net)->slirp;
-    if (slirp && !standalone) {
-        int slirpfd = qemuSlirpGetFD(slirp);
-        virCommandPassFD(cmd, slirpfd,
-                         VIR_COMMAND_PASS_FD_CLOSE_PARENT);
-        slirpfdName = g_strdup_printf("%d", slirpfd);
-    }
-
     for (n = netpriv->tapfds; n; n = n->next) {
         if (qemuFDPassTransferCommand(n->data, cmd) < 0)
             return -1;
@@ -8908,11 +8899,11 @@ qemuBuildInterfaceCommandLine(virQEMUDriver *driver,
             return -1;
     }

-    if (qemuFDPassTransferCommand(netpriv->vdpafd, cmd) < 0)
+    if (qemuFDPassTransferCommand(netpriv->slirpfd, cmd) < 0 ||
+        qemuFDPassTransferCommand(netpriv->vdpafd, cmd) < 0)
         return -1;

-    if (!(hostnetprops = qemuBuildHostNetProps(net,
-                                               slirpfdName)))
+    if (!(hostnetprops = qemuBuildHostNetProps(net)))
         goto cleanup;

     if (qemuBuildNetdevCommandlineFromJSON(cmd, hostnetprops, qemuCaps) < 0)
diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h
index 9bb63d9598..84877b3d90 100644
--- a/src/qemu/qemu_command.h
+++ b/src/qemu/qemu_command.h
@@ -86,8 +86,7 @@ virJSONValue *
 qemuBuildChannelGuestfwdNetdevProps(virDomainChrDef *chr);

 virJSONValue *
-qemuBuildHostNetProps(virDomainNetDef *net,
-                      const char *slirpfd);
+qemuBuildHostNetProps(virDomainNetDef *net);

 int
 qemuBuildInterfaceConnect(virDomainObj *vm,
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index 8f5e971570..3f368551e3 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -1318,9 +1318,6 @@ qemuDomainAttachNetDevice(virQEMUDriver *driver,
                                "%s", _("Failed to start slirp"));
                 goto cleanup;
             }
-
-            slirpfd = qemuSlirpGetFD(slirp);
-            slirpfdName = g_strdup_printf("slirpfd-%s", net->info.alias);
         }
         break;

@@ -1376,8 +1373,7 @@ qemuDomainAttachNetDevice(virQEMUDriver *driver,
         virNetDevSetMTU(net->ifname, net->mtu) < 0)
         goto cleanup;

-    if (!(netprops = qemuBuildHostNetProps(net,
-                                           slirpfdName)))
+    if (!(netprops = qemuBuildHostNetProps(net)))
         goto cleanup;

     qemuDomainObjEnterMonitor(driver, vm);
@@ -1396,7 +1392,8 @@ qemuDomainAttachNetDevice(virQEMUDriver *driver,
         }
     }

-    if (qemuFDPassTransferMonitor(netpriv->vdpafd, priv->mon) < 0) {
+    if (qemuFDPassTransferMonitor(netpriv->slirpfd, priv->mon) < 0 ||
+        qemuFDPassTransferMonitor(netpriv->vdpafd, priv->mon) < 0) {
         qemuDomainObjExitMonitor(vm);
         goto cleanup;
     }
diff --git a/src/qemu/qemu_slirp.c b/src/qemu/qemu_slirp.c
index 136e4b29d2..b62934f292 100644
--- a/src/qemu/qemu_slirp.c
+++ b/src/qemu/qemu_slirp.c
@@ -251,7 +251,8 @@ qemuSlirpStart(virDomainObj *vm,
 {
     qemuDomainObjPrivate *priv = vm->privateData;
     virQEMUDriver *driver = priv->driver;
-    qemuSlirp *slirp = QEMU_DOMAIN_NETWORK_PRIVATE(net)->slirp;
+    qemuDomainNetworkPrivate *netpriv = QEMU_DOMAIN_NETWORK_PRIVATE(net);
+    qemuSlirp *slirp = netpriv->slirp;
     g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
     g_autoptr(virCommand) cmd = NULL;
     g_autofree char *pidfile = NULL;
@@ -262,6 +263,7 @@ qemuSlirpStart(virDomainObj *vm,
     int cmdret = 0;
     VIR_AUTOCLOSE errfd = -1;
     bool killDBusDaemon = false;
+    g_autofree char *fdname = g_strdup_printf("slirpfd-%s", net->info.alias);

     if (!slirp)
         return 0;
@@ -359,6 +361,10 @@ qemuSlirpStart(virDomainObj *vm,

     slirp->pid = pid;

+    netpriv->slirpfd = qemuFDPassNewDirect(fdname, priv);
+
+    qemuFDPassAddFD(netpriv->slirpfd, &slirp->fd[0], NULL);
+
     return 0;

  error:
-- 
2.35.1



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