i386/tdx: Remove task->watch only when it's valid

In some case (e.g., failed to connect to QGS socket),
tdx_generate_quote_cleanup() is called with task->watch invalid. It
triggers assertion of

  qemu-system-x86_64: GLib: g_source_remove: assertion 'tag > 0' failed

Fix it by checking task->watch.

Fixes: 40da501d8989 ("i386/tdx: handle TDG.VP.VMCALL<GetQuote>")
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Link: https://lore.kernel.org/r/20250625035505.2770580-1-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/target/i386/kvm/tdx-quote-generator.c b/target/i386/kvm/tdx-quote-generator.c
index f59715f6175126721d72e40c15895d9977e7932e..dee8334b27acd3a3ac64e7bdd77d29982fca67ba 100644 (file)
--- a/target/i386/kvm/tdx-quote-generator.c
+++ b/target/i386/kvm/tdx-quote-generator.c
@@ -75,7 +75,9 @@ static void tdx_generate_quote_cleanup(TdxGenerateQuoteTask *task)
 {
     timer_del(&task->timer);
 
-    g_source_remove(task->watch);
+    if (task->watch) {
+        g_source_remove(task->watch);
+    }
     qio_channel_close(QIO_CHANNEL(task->sioc), NULL);
     object_unref(OBJECT(task->sioc));