[libvirt] [PATCH] qemu: Introduce state_lock_timeout to qemu.conf

[Yi Wang]

When doing some job holding state lock for a long time,
we may come across error:
"Timed out during operation: cannot acquire state change lock"
Well, sometimes it's not a problem and users wanner continue
to wait, and this patch allow users decide how long time they
can wait the state lock.

Signed-off-by: Yi Wang <wang.yi59 at zte.com.cn>
Reviewed-by: Xi Xu <xu.xi8 at zte.com.cn>
---
 src/qemu/libvirtd_qemu.aug         | 1 +
 src/qemu/qemu.conf                 | 6 ++++++
 src/qemu/qemu_conf.c               | 3 +++
 src/qemu/qemu_conf.h               | 2 ++
 src/qemu/qemu_domain.c             | 6 +++++-
 src/qemu/test_libvirtd_qemu.aug.in | 1 +
 6 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/qemu/libvirtd_qemu.aug b/src/qemu/libvirtd_qemu.aug
index ddc4bbf..f7287ae 100644
--- a/src/qemu/libvirtd_qemu.aug
+++ b/src/qemu/libvirtd_qemu.aug
@@ -93,6 +93,7 @@ module Libvirtd_qemu =
                  | limits_entry "max_core"
                  | bool_entry "dump_guest_core"
                  | str_entry "stdio_handler"
+                 | int_entry "state_lock_timeout"
 
    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 cd57b3c..e88db3f 100644
--- a/src/qemu/qemu.conf
+++ b/src/qemu/qemu.conf
@@ -813,3 +813,9 @@
 #
 #swtpm_user = "tss"
 #swtpm_group = "tss"
+
+# Override the timeout (in seconds) for acquiring state lock.
+#
+# Default is 0
+#
+#state_lock_timeout = 60
diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
index a4f545e..f452714 100644
--- a/src/qemu/qemu_conf.c
+++ b/src/qemu/qemu_conf.c
@@ -863,6 +863,9 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg,
     if (virConfGetValueUInt(conf, "keepalive_count", &cfg->keepAliveCount) < 0)
         goto cleanup;
 
+    if (virConfGetValueInt(conf, "state_lock_timeout", &cfg->stateLockTimeout) < 0)
+        goto cleanup;
+
     if (virConfGetValueInt(conf, "seccomp_sandbox", &cfg->seccompSandbox) < 0)
         goto cleanup;
 
diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h
index a8d84ef..97cf2e1 100644
--- a/src/qemu/qemu_conf.h
+++ b/src/qemu/qemu_conf.h
@@ -190,6 +190,8 @@ struct _virQEMUDriverConfig {
     int keepAliveInterval;
     unsigned int keepAliveCount;
 
+    int stateLockTimeout;
+
     int seccompSandbox;
 
     char *migrateHost;
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 886e3fb..d375a73 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -6714,7 +6714,11 @@ qemuDomainObjBeginJobInternal(virQEMUDriverPtr driver,
     }
 
     priv->jobs_queued++;
-    then = now + QEMU_JOB_WAIT_TIME;
+    if (cfg->stateLockTimeout > 0)
+        then = now + cfg->stateLockTimeout;
+    else
+        then = now + QEMU_JOB_WAIT_TIME;
+
 
  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 f1e8806..dc5de96 100644
--- a/src/qemu/test_libvirtd_qemu.aug.in
+++ b/src/qemu/test_libvirtd_qemu.aug.in
@@ -105,3 +105,4 @@ module Test_libvirtd_qemu =
 { "pr_helper" = "/usr/bin/qemu-pr-helper" }
 { "swtpm_user" = "tss" }
 { "swtpm_group" = "tss" }
+{ "state_lock_timeout" = "60" }
-- 
1.8.3.1