[libvirt] [PATCH] conf: Don't drop console definition on domain restart

[Michal Privoznik]

One of my latest patches 2e37bf42d28d8bb5d045b206587c64643c64d02a
copy serial console definition. On domain shutdown we save this
info into state XML. However, later on the daemon start we simply
drop this info and since we are not re-reading qemu log,
vm->def->consoles[0] does not get populated with copy. Therefore
we need to avoid dropping console definition if it is just alias
for serial console.
---
 src/conf/domain_conf.c |   76 +++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 69 insertions(+), 7 deletions(-)

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index d365cee..f04e477 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -1042,6 +1042,57 @@ void virDomainChrSourceDefFree(virDomainChrSourceDefPtr def)
     VIR_FREE(def);
 }
 
+/* virDomainChrSourceDefIsEqual:
+ * @src: Source
+ * @tgt: Target
+ *
+ * Compares source and target if they contain
+ * the same information.
+ */
+static bool
+virDomainChrSourceDefIsEqual(const virDomainChrSourceDef *src,
+                             const virDomainChrSourceDef *tgt)
+{
+    if (tgt->type != src->type)
+        return false;
+
+    switch (src->type) {
+    case VIR_DOMAIN_CHR_TYPE_PTY:
+    case VIR_DOMAIN_CHR_TYPE_DEV:
+    case VIR_DOMAIN_CHR_TYPE_FILE:
+    case VIR_DOMAIN_CHR_TYPE_PIPE:
+        return STREQ_NULLABLE(src->data.file.path, tgt->data.file.path);
+        break;
+    case VIR_DOMAIN_CHR_TYPE_UDP:
+        return STREQ_NULLABLE(src->data.udp.bindHost, tgt->data.udp.bindHost) &&
+            STREQ_NULLABLE(src->data.udp.bindService, tgt->data.udp.bindService) &&
+            STREQ_NULLABLE(src->data.udp.connectHost, tgt->data.udp.connectHost) &&
+            STREQ_NULLABLE(src->data.udp.connectService, tgt->data.udp.connectService);
+        break;
+    case VIR_DOMAIN_CHR_TYPE_TCP:
+        return src->data.tcp.listen == tgt->data.tcp.listen &&
+            src->data.tcp.protocol == tgt->data.tcp.protocol &&
+            STREQ_NULLABLE(src->data.tcp.host, tgt->data.tcp.host) &&
+            STREQ_NULLABLE(src->data.tcp.service, tgt->data.tcp.service);
+        break;
+    case VIR_DOMAIN_CHR_TYPE_UNIX:
+        return src->data.nix.listen == tgt->data.nix.listen &&
+            STREQ_NULLABLE(src->data.nix.path, tgt->data.nix.path);
+        break;
+
+    case VIR_DOMAIN_CHR_TYPE_VC:
+    case VIR_DOMAIN_CHR_TYPE_STDIO:
+    case VIR_DOMAIN_CHR_TYPE_SPICEVMC:
+        /* nada */
+        return true;
+    }
+
+    /* This should happen only on new,
+     * yet unhandled type */
+
+    return false;
+}
+
 void virDomainChrDefFree(virDomainChrDefPtr def)
 {
     if (!def)
@@ -7308,6 +7359,7 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
         goto no_memory;
 
     for (i = 0 ; i < n ; i++) {
+        bool create_stub = true;
         virDomainChrDefPtr chr = virDomainChrDefParseXML(caps,
                                                          def,
                                                          nodes[i],
@@ -7325,7 +7377,9 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
          * So if we see that this console device should
          * be a serial device, then we move the config
          * over to def->serials[0] (or discard it if
-         * that already exists
+         * that already exists). However, given console
+         * can already be filled with aliased data of
+         * def->serials[0]. Keep it then.
          *
          * We then fill def->consoles[0] with a stub
          * just so we get sequencing correct for consoles
@@ -7341,7 +7395,13 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
 
             /* Either discard or move this chr to the serial config */
             if (def->nserials != 0) {
-                virDomainChrDefFree(chr);
+                if (virDomainChrSourceDefIsEqual(&def->serials[0]->source,
+                                                 &chr->source)) {
+                    /* Alias to def->serial[0]. Skip it */
+                    create_stub = false;
+                } else {
+                    virDomainChrDefFree(chr);
+                }
             } else {
                 if (VIR_ALLOC_N(def->serials, 1) < 0) {
                     virDomainChrDefFree(chr);
@@ -7353,11 +7413,13 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
                 chr->target.port = 0;
             }
 
-            /* And create a stub placeholder */
-            if (VIR_ALLOC(chr) < 0)
-                goto no_memory;
-            chr->deviceType = VIR_DOMAIN_CHR_DEVICE_TYPE_CONSOLE;
-            chr->targetType = VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_SERIAL;
+            if (create_stub) {
+                /* And create a stub placeholder */
+                if (VIR_ALLOC(chr) < 0)
+                    goto no_memory;
+                chr->deviceType = VIR_DOMAIN_CHR_DEVICE_TYPE_CONSOLE;
+                chr->targetType = VIR_DOMAIN_CHR_CONSOLE_TARGET_TYPE_SERIAL;
+            }
         }
 
         chr->target.port = i;
-- 
1.7.3.4