[PATCH] qemu: clear residual QMP caps processes during QEMU driver initialization

[Bihong Yu]

>From c328ff62b11d58553fd2032a85fd3295e009b3d3 Mon Sep 17 00:00:00 2001
From: Bihong Yu <yubihong at huawei.com>
Date: Fri, 17 Jul 2020 16:55:12 +0800
Subject: [PATCH] qemu: clear residual QMP caps processes during QEMU driver
 initialization

In some cases, the QMP capabilities processes possible residue. So we need to
clear the residual QMP caps processes during starting libvirt.

Signed-off-by:Bihong Yu <yubihong at huawei.com>
---
 src/qemu/qemu_driver.c  |  2 ++
 src/qemu/qemu_process.c | 40 ++++++++++++++++++++++++++++++++++++++++
 src/qemu/qemu_process.h |  2 ++
 3 files changed, 44 insertions(+)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index d185666..d627fd7 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -889,6 +889,8 @@ qemuStateInitialize(bool privileged,
         run_gid = cfg->group;
     }

+    qemuProcessQMPClear(cfg->libDir);
+
     qemu_driver->qemuCapsCache = virQEMUCapsCacheNew(cfg->libDir,
                                                      cfg->cacheDir,
                                                      run_uid,
diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
index 70fc24b..d545e3e 100644
--- a/src/qemu/qemu_process.c
+++ b/src/qemu/qemu_process.c
@@ -8312,6 +8312,46 @@ static qemuMonitorCallbacks callbacks = {
 };


+/**
+ * qemuProcessQMPClear
+ *
+ * Try to kill residual QMP caps processes
+ */
+void
+qemuProcessQMPClear(const char *libDir)
+{
+    virErrorPtr orig_err;
+    DIR *dirp = NULL;
+    struct dirent *dp;
+
+    if (!virFileExists(libDir))
+        return;
+
+    if (virDirOpen(&dirp, libDir) < 0)
+        return;
+
+    virErrorPreserveLast(&orig_err);
+    while (virDirRead(dirp, &dp, libDir) > 0) {
+        g_autofree char *qmp_uniqDir = NULL;
+        g_autofree char *qmp_pidfile = NULL;
+
+        if (!STRPREFIX(dp->d_name, "qmp-"))
+            continue;
+
+        qmp_uniqDir = g_strdup_printf("%s/%s", libDir, dp->d_name);
+        qmp_pidfile = g_strdup_printf("%s/%s", qmp_uniqDir, "qmp.pid");
+
+        ignore_value(virPidFileForceCleanupPath(qmp_pidfile));
+
+        if (qmp_uniqDir)
+            rmdir(qmp_uniqDir);
+    }
+    virErrorRestore(&orig_err);
+
+    VIR_DIR_CLOSE(dirp);
+}
+
+
 static void
 qemuProcessQMPStop(qemuProcessQMPPtr proc)
 {
diff --git a/src/qemu/qemu_process.h b/src/qemu/qemu_process.h
index 15e67b9..b039e6c 100644
--- a/src/qemu/qemu_process.h
+++ b/src/qemu/qemu_process.h
@@ -233,6 +233,8 @@ qemuProcessQMPPtr qemuProcessQMPNew(const char *binary,
                                     gid_t runGid,
                                     bool forceTCG);

+void qemuProcessQMPClear(const char *libDir);
+
 void qemuProcessQMPFree(qemuProcessQMPPtr proc);

 int qemuProcessQMPStart(qemuProcessQMPPtr proc);
-- 
1.8.3.1