From af78cb04867263900ecb682279d79e8b9af84b7b Mon Sep 17 00:00:00 2001
From: Maxim Nestratov <mnestratov@virtuozzo.com>
Date: Fri, 9 Dec 2016 17:28:05 +0300
Subject: [PATCH] qemu: Allow to specify pit timer tick policy=discard

Separate out the "policy=discard" into it's own specific
qemu command line.

We'll rename "kvm-pit-device" test case to be "kvm-pit-discard"
since it has the syntax we'd be using.

Signed-off-by: Maxim Nestratov <mnestratov@virtuozzo.com>
---
 src/qemu/qemu_command.c                                | 10 ++++++++--
 ...t-device.args => qemuxml2argv-kvm-pit-discard.args} |  0
 ...pit-device.xml => qemuxml2argv-kvm-pit-discard.xml} |  2 +-
 tests/qemuxml2argvtest.c                               |  1 +
 4 files changed, 10 insertions(+), 3 deletions(-)
 rename tests/qemuxml2argvdata/{qemuxml2argv-kvm-pit-device.args => qemuxml2argv-kvm-pit-discard.args} (100%)
 rename tests/qemuxml2argvdata/{qemuxml2argv-kvm-pit-device.xml => qemuxml2argv-kvm-pit-discard.xml} (95%)

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 10325e3e5e..d459f8e3e3 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -6261,9 +6261,15 @@ qemuBuildClockCommandLine(virCommandPtr cmd,
                     return -1;
                 }
                 break;
-            case VIR_DOMAIN_TIMER_TICKPOLICY_MERGE:
             case VIR_DOMAIN_TIMER_TICKPOLICY_DISCARD:
-                /* no way to support these modes for pit in qemu */
+                if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_KVM_PIT_TICK_POLICY))
+                    virCommandAddArgList(cmd, "-global",
+                                         "kvm-pit.lost_tick_policy=discard", NULL);
+                else if (virQEMUCapsGet(qemuCaps, QEMU_CAPS_NO_KVM_PIT))
+                    virCommandAddArg(cmd, "-no-kvm-pit-reinjection");
+                break;
+            case VIR_DOMAIN_TIMER_TICKPOLICY_MERGE:
+                /* no way to support this mode for pit in qemu */
                 virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                                _("unsupported pit tickpolicy '%s'"),
                                virDomainTimerTickpolicyTypeToString(def->clock.timers[i]->tickpolicy));
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-kvm-pit-device.args b/tests/qemuxml2argvdata/qemuxml2argv-kvm-pit-discard.args
similarity index 100%
rename from tests/qemuxml2argvdata/qemuxml2argv-kvm-pit-device.args
rename to tests/qemuxml2argvdata/qemuxml2argv-kvm-pit-discard.args
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-kvm-pit-device.xml b/tests/qemuxml2argvdata/qemuxml2argv-kvm-pit-discard.xml
similarity index 95%
rename from tests/qemuxml2argvdata/qemuxml2argv-kvm-pit-device.xml
rename to tests/qemuxml2argvdata/qemuxml2argv-kvm-pit-discard.xml
index 7835a1b03b..d8ddcbaf4c 100644
--- a/tests/qemuxml2argvdata/qemuxml2argv-kvm-pit-device.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-kvm-pit-discard.xml
@@ -9,7 +9,7 @@
     <boot dev='hd'/>
   </os>
   <clock offset='utc'>
-    <timer name='pit' tickpolicy='delay'/>
+    <timer name='pit' tickpolicy='discard'/>
   </clock>
   <on_poweroff>destroy</on_poweroff>
   <on_reboot>restart</on_reboot>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index 559dd3ba53..ba5e3b87b6 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -2275,6 +2275,7 @@ mymain(void)
     qemuTestSetHostArch(driver.caps, VIR_ARCH_NONE);
 
     DO_TEST("kvm-pit-delay", QEMU_CAPS_KVM_PIT_TICK_POLICY);
+    DO_TEST("kvm-pit-discard", QEMU_CAPS_KVM_PIT_TICK_POLICY);
 
     DO_TEST("panic", QEMU_CAPS_DEVICE_PANIC,
             QEMU_CAPS_NODEFCONFIG);