[libvirt] [PATCH] qemu: Generate agent socket path if missing

[Michal Privoznik]

It's not desired to force users imagine path for a socket they
are not even supposed to connect to. On the other hand, we
already have a release where the qemu agent socket path is
exposed to XML, so we cannot silently drop it from there.
The new path is generated in form:

$LOCALSTATEDIR/lib/libvirt/qemu/channel/target/$domain.$name
---
 libvirt.spec.in        |  1 +
 src/Makefile.am        |  1 +
 src/conf/domain_conf.c | 34 ++++++++++++++++------------------
 src/qemu/qemu_domain.c | 16 ++++++++++++++++
 4 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/libvirt.spec.in b/libvirt.spec.in
index 328b009..11fc12d 100644
--- a/libvirt.spec.in
+++ b/libvirt.spec.in
@@ -1719,6 +1719,7 @@ fi
     %if %{with_qemu}
 %ghost %dir %attr(0700, root, root) %{_localstatedir}/run/libvirt/qemu/
 %dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/lib/libvirt/qemu/
+%dir %attr{0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/lib/libvirt/qemu/channel/target/
 %dir %attr(0750, %{qemu_user}, %{qemu_group}) %{_localstatedir}/cache/libvirt/qemu/
     %endif
     %if %{with_lxc}
diff --git a/src/Makefile.am b/src/Makefile.am
index fc6b846..9576da8 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -2097,6 +2097,7 @@ if WITH_SANLOCK
 endif
 if WITH_QEMU
 	$(MKDIR_P) "$(DESTDIR)$(localstatedir)/lib/libvirt/qemu"
+	$(MKDIR_P) "$(DESTDIR)$(localstatedir)/lib/libvirt/qemu/channel/target"
 	$(MKDIR_P) "$(DESTDIR)$(localstatedir)/run/libvirt/qemu"
 	$(MKDIR_P) "$(DESTDIR)$(localstatedir)/cache/libvirt/qemu"
 	$(MKDIR_P) "$(DESTDIR)$(localstatedir)/log/libvirt/qemu"
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 03e5740..3ff548a 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -6464,7 +6464,9 @@ virDomainChrSourceDefParseXML(virDomainChrSourceDefPtr def,
         break;
 
     case VIR_DOMAIN_CHR_TYPE_UNIX:
-        if (path == NULL) {
+        /* path can be auto generated */
+        if (!path &&
+            chr_def->targetType != VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_VIRTIO) {
             virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                            _("Missing source path attribute for char device"));
             goto error;
@@ -6559,7 +6561,6 @@ virDomainChrDefParseXML(xmlXPathContextPtr ctxt,
     char *type = NULL;
     const char *nodeName;
     virDomainChrDefPtr def;
-    int remaining;
     bool seenTarget = false;
 
     if (!(def = virDomainChrDefNew()))
@@ -6583,29 +6584,26 @@ virDomainChrDefParseXML(xmlXPathContextPtr ctxt,
     }
 
     cur = node->children;
-    remaining = virDomainChrSourceDefParseXML(&def->source, cur, flags,
-                                              def, ctxt,
-                                              vmSeclabels, nvmSeclabels);
-    if (remaining < 0)
-        goto error;
-    if (remaining) {
-        while (cur != NULL) {
-            if (cur->type == XML_ELEMENT_NODE) {
-                if (xmlStrEqual(cur->name, BAD_CAST "target")) {
-                    seenTarget = true;
-                    if (virDomainChrDefParseTargetXML(def, cur) < 0) {
-                        goto error;
-                    }
+    while (cur != NULL) {
+        if (cur->type == XML_ELEMENT_NODE) {
+            if (xmlStrEqual(cur->name, BAD_CAST "target")) {
+                seenTarget = true;
+                if (virDomainChrDefParseTargetXML(def, cur) < 0) {
+                    goto error;
                 }
             }
-            cur = cur->next;
         }
+        cur = cur->next;
     }
 
     if (!seenTarget &&
         ((def->targetType = virDomainChrDefaultTargetType(def->deviceType)) < 0))
         goto cleanup;
 
+    if (virDomainChrSourceDefParseXML(&def->source, node->children, flags, def,
+                                      ctxt, vmSeclabels, nvmSeclabels) < 0)
+        goto error;
+
     if (def->source.type == VIR_DOMAIN_CHR_TYPE_SPICEVMC) {
         if (def->targetType != VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_VIRTIO) {
             virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
@@ -13897,8 +13895,8 @@ virDomainChrSourceDefFormat(virBufferPtr buf,
     case VIR_DOMAIN_CHR_TYPE_UNIX:
         virBufferAsprintf(buf, "      <source mode='%s'",
                           def->data.nix.listen ? "bind" : "connect");
-        virBufferEscapeString(buf, " path='%s'/>\n",
-                              def->data.nix.path);
+        virBufferEscapeString(buf, " path='%s'", def->data.nix.path);
+        virBufferAddLit(buf, "/>\n");
         break;
     }
 
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 3d6eef4..967890f 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -738,6 +738,22 @@ qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
         (def->os.arch == VIR_ARCH_S390 || def->os.arch == VIR_ARCH_S390X))
         dev->data.chr->targetType = VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_VIRTIO;
 
+    /* auto generate unix socket path */
+    if (dev->type == VIR_DOMAIN_DEVICE_CHR &&
+        dev->data.chr->deviceType == VIR_DOMAIN_CHR_DEVICE_TYPE_CHANNEL &&
+        dev->data.chr->targetType == VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_VIRTIO &&
+        dev->data.chr->source.type == VIR_DOMAIN_CHR_TYPE_UNIX &&
+        !dev->data.chr->source.data.nix.path &&
+        (cfg || (driver && (cfg = virQEMUDriverGetConfig(driver))))) {
+
+        if (virAsprintf(&dev->data.chr->source.data.nix.path,
+                        "%s/channel/target/%s.%s",
+                        cfg->libDir, def->name,
+                        dev->data.chr->target.name) < 0)
+            goto no_memory;
+        dev->data.chr->source.data.nix.listen = true;
+    }
+
     ret = 0;
 
 cleanup:
-- 
1.8.1.5