[PATCH] conf: Add qemu_job_wait_time option

[MIKI Nobuhiro]

The waiting time to acquire the lock times out, which leads to a segment fault.
In essence we should make improvements around locks, but as a workaround we
will change the timeout to allow the user to increase it.
This value was defined as 30 seconds, so use it as the default value.
The logs are as follows:

```
Timed out during operation: cannot acquire state change lock \
   (held by monitor=remoteDispatchDomainCreateWithFlags)
libvirtd.service: main process exited, code=killed,status=11/SEGV
```

Signed-off-by: MIKI Nobuhiro <nmiki at yahoo-corp.jp>
---
 docs/news.xml                      | 9 +++++++++
 src/qemu/libvirtd_qemu.aug         | 1 +
 src/qemu/qemu.conf                 | 3 +++
 src/qemu/qemu_conf.c               | 3 +++
 src/qemu/qemu_conf.h               | 2 ++
 src/qemu/qemu_domain.c             | 7 ++-----
 src/qemu/test_libvirtd_qemu.aug.in | 1 +
 7 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/docs/news.xml b/docs/news.xml
index 80819ae..3755c49 100644
--- a/docs/news.xml
+++ b/docs/news.xml
@@ -119,6 +119,15 @@
           Bounds Checking) and IBS (Indirect Branch Speculation).
         </description>
       </change>
+      <change>
+        <summary>
+          conf: Add job wait time setting to qemu.conf
+        </summary>
+        <description>
+          How many seconds the new job waits for the existing job to finish.
+          This only affects if you are using qemu as driver.
+        </description>
+      </change>
     </section>
     <section title="Improvements">
     </section>
diff --git a/src/qemu/libvirtd_qemu.aug b/src/qemu/libvirtd_qemu.aug
index 404498b..76c896e 100644
--- a/src/qemu/libvirtd_qemu.aug
+++ b/src/qemu/libvirtd_qemu.aug
@@ -97,6 +97,7 @@ module Libvirtd_qemu =
                  | bool_entry "dump_guest_core"
                  | str_entry "stdio_handler"
                  | int_entry "max_threads_per_process"
+                 | int_entry "qemu_job_wait_time"
 
    let device_entry = bool_entry "mac_filter"
                  | bool_entry "relaxed_acs_check"
diff --git a/src/qemu/qemu.conf b/src/qemu/qemu.conf
index abdbf07..a05aaa5 100644
--- a/src/qemu/qemu.conf
+++ b/src/qemu/qemu.conf
@@ -612,6 +612,9 @@
 #
 #max_threads_per_process = 0
 
+# How many seconds the new job waits for the existing job to finish.
+#qemu_job_wait_time = 30
+
 # If max_core is set to a non-zero integer, then QEMU will be
 # permitted to create core dumps when it crashes, provided its
 # RAM size is smaller than the limit set.
diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
index c598240..34d29ec 100644
--- a/src/qemu/qemu_conf.c
+++ b/src/qemu/qemu_conf.c
@@ -272,6 +272,7 @@ virQEMUDriverConfigPtr virQEMUDriverConfigNew(bool privileged,
     cfg->keepAliveInterval = 5;
     cfg->keepAliveCount = 5;
     cfg->seccompSandbox = -1;
+    cfg->qemuJobWaitTime = 30;
 
     cfg->logTimestamp = true;
     cfg->glusterDebugLevel = 4;
@@ -655,6 +656,8 @@ virQEMUDriverConfigLoadProcessEntry(virQEMUDriverConfigPtr cfg,
         return -1;
     if (virConfGetValueUInt(conf, "max_threads_per_process", &cfg->maxThreadsPerProc) < 0)
         return -1;
+    if (virConfGetValueUInt(conf, "qemu_job_wait_time", &cfg->qemuJobWaitTime) < 0)
+        return -1;
 
     if (virConfGetValueType(conf, "max_core") == VIR_CONF_STRING) {
         if (virConfGetValueString(conf, "max_core", &corestr) < 0)
diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h
index b9ef455..49dd7b6 100644
--- a/src/qemu/qemu_conf.h
+++ b/src/qemu/qemu_conf.h
@@ -218,6 +218,8 @@ struct _virQEMUDriverConfig {
     gid_t swtpm_group;
 
     char **capabilityfilters;
+
+    unsigned int qemuJobWaitTime;
 };
 
 G_DEFINE_AUTOPTR_CLEANUP_FUNC(virQEMUDriverConfig, virObjectUnref);
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index d63ec23..4badc0f 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -6212,9 +6212,6 @@ qemuDomainObjCanSetJob(qemuDomainObjPrivatePtr priv,
              priv->job.agentActive == QEMU_AGENT_JOB_NONE));
 }
 
-/* Give up waiting for mutex after 30 seconds */
-#define QEMU_JOB_WAIT_TIME (1000ull * 30)
-
 /**
  * qemuDomainObjBeginJobInternal:
  * @driver: qemu driver
@@ -6225,7 +6222,7 @@ qemuDomainObjCanSetJob(qemuDomainObjPrivatePtr priv,
  *
  * Acquires job for a domain object which must be locked before
  * calling. If there's already a job running waits up to
- * QEMU_JOB_WAIT_TIME after which the functions fails reporting
+ * cfg->qemuJobWaitTime after which the functions fails reporting
  * an error unless @nowait is set.
  *
  * If @nowait is true this function tries to acquire job and if
@@ -6272,7 +6269,7 @@ qemuDomainObjBeginJobInternal(virQEMUDriverPtr driver,
         return -1;
 
     priv->jobs_queued++;
-    then = now + QEMU_JOB_WAIT_TIME;
+    then = now + 1000ull * cfg->qemuJobWaitTime;
 
  retry:
     if ((!async && job != QEMU_JOB_DESTROY) &&
diff --git a/src/qemu/test_libvirtd_qemu.aug.in b/src/qemu/test_libvirtd_qemu.aug.in
index 19da591..b2886df 100644
--- a/src/qemu/test_libvirtd_qemu.aug.in
+++ b/src/qemu/test_libvirtd_qemu.aug.in
@@ -76,6 +76,7 @@ module Test_libvirtd_qemu =
 { "max_processes" = "0" }
 { "max_files" = "0" }
 { "max_threads_per_process" = "0" }
+{ "qemu_job_wait_time" = "30" }
 { "max_core" = "unlimited" }
 { "dump_guest_core" = "1" }
 { "mac_filter" = "1" }
-- 
1.8.3.1