From 7373c4e48f293fb4d361b1bf2d0986166d8480be Mon Sep 17 00:00:00 2001
From: Jiri Denemark <jdenemar@redhat.com>
Date: Thu, 23 Mar 2017 15:54:38 +0100
Subject: [PATCH] qemu: Add support for setting TSC frequency

QEMU allows for TSC frequency to be explicitly set to enable migration
with invtsc (migration fails if the destination QEMU cannot set the
exact same frequency used when starting the domain on the source host).

Libvirt already supports setting the TSC frequency in the XML using

    <clock>
      <timer name='tsc' frequency='1234567890'/>
    </clock>

which will be transformed into

    -cpu Model,tsc-frequency=1234567890

QEMU command line.

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
---
 src/qemu/qemu_command.c                       | 16 +++++----
 .../qemuxml2argv-cpu-tsc-frequency.args       | 23 ++++++++++++
 .../qemuxml2argv-cpu-tsc-frequency.xml        | 35 +++++++++++++++++++
 tests/qemuxml2argvtest.c                      |  1 +
 4 files changed, 69 insertions(+), 6 deletions(-)
 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-cpu-tsc-frequency.args
 create mode 100644 tests/qemuxml2argvdata/qemuxml2argv-cpu-tsc-frequency.xml

diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index 2a2ab3e9b0..987b95afa5 100644
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@@ -6329,12 +6329,12 @@ qemuBuildClockCommandLine(virCommandPtr cmd,
     for (i = 0; i < def->clock.ntimers; i++) {
         switch ((virDomainTimerNameType) def->clock.timers[i]->name) {
         case VIR_DOMAIN_TIMER_NAME_PLATFORM:
-        case VIR_DOMAIN_TIMER_NAME_TSC:
             virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                            _("unsupported timer type (name) '%s'"),
                            virDomainTimerNameTypeToString(def->clock.timers[i]->name));
             return -1;
 
+        case VIR_DOMAIN_TIMER_NAME_TSC:
         case VIR_DOMAIN_TIMER_NAME_KVMCLOCK:
         case VIR_DOMAIN_TIMER_NAME_HYPERVCLOCK:
             /* Timers above are handled when building -cpu.  */
@@ -6921,19 +6921,23 @@ qemuBuildCpuCommandLine(virCommandPtr cmd,
     for (i = 0; i < def->clock.ntimers; i++) {
         virDomainTimerDefPtr timer = def->clock.timers[i];
 
-        if (timer->present == -1)
-            continue;
-
-        if (timer->name == VIR_DOMAIN_TIMER_NAME_KVMCLOCK) {
+        if (timer->name == VIR_DOMAIN_TIMER_NAME_KVMCLOCK &&
+            timer->present != -1) {
             virBufferAsprintf(&buf, "%s,%ckvmclock",
                               have_cpu ? "" : default_model,
                               timer->present ? '+' : '-');
             have_cpu = true;
         } else if (timer->name == VIR_DOMAIN_TIMER_NAME_HYPERVCLOCK &&
-                   timer->present) {
+                   timer->present == 1) {
             virBufferAsprintf(&buf, "%s,hv_time",
                               have_cpu ? "" : default_model);
             have_cpu = true;
+        } else if (timer->name == VIR_DOMAIN_TIMER_NAME_TSC &&
+                   timer->frequency > 0) {
+            virBufferAsprintf(&buf, "%s,tsc-frequency=%lu",
+                              have_cpu ? "" : default_model,
+                              timer->frequency);
+            have_cpu = true;
         }
     }
 
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-cpu-tsc-frequency.args b/tests/qemuxml2argvdata/qemuxml2argv-cpu-tsc-frequency.args
new file mode 100644
index 0000000000..50223fab2b
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-cpu-tsc-frequency.args
@@ -0,0 +1,23 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test \
+QEMU_AUDIO_DRV=none \
+/usr/bin/qemu \
+-name QEMUGuest1 \
+-S \
+-M pc \
+-cpu Haswell,+vme,+ds,+acpi,+ss,+ht,+tm,+pbe,+dtes64,+monitor,+ds_cpl,+vmx,\
++smx,+est,+tm2,+xtpr,+pdcm,+osxsave,+f16c,+rdrand,+pdpe1gb,+abm,+lahf_lm,\
++invtsc,tsc-frequency=3504000000 \
+-m 214 \
+-smp 1,sockets=1,cores=1,threads=1 \
+-uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \
+-nographic \
+-nodefaults \
+-monitor unix:/tmp/lib/domain--1-QEMUGuest1/monitor.sock,server,nowait \
+-no-acpi \
+-boot c \
+-usb \
+-device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
diff --git a/tests/qemuxml2argvdata/qemuxml2argv-cpu-tsc-frequency.xml b/tests/qemuxml2argvdata/qemuxml2argv-cpu-tsc-frequency.xml
new file mode 100644
index 0000000000..72afe6cd27
--- /dev/null
+++ b/tests/qemuxml2argvdata/qemuxml2argv-cpu-tsc-frequency.xml
@@ -0,0 +1,35 @@
+<domain type='kvm'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <title>A description of the test machine.</title>
+  <description>
+      A test of qemu&apos;s minimal configuration.
+      This test also tests the description and title elements.
+  </description>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <cpu mode='host-model'>
+    <model fallback='allow'/>
+    <feature policy='require' name='invtsc'/>
+  </cpu>
+  <clock offset='utc'>
+    <timer name='tsc' frequency='3504000000'/>
+  </clock>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <controller type='usb' index='0'/>
+    <controller type='ide' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <input type='mouse' bus='ps2'/>
+    <input type='keyboard' bus='ps2'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>
diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c
index e523236df4..41461eadc8 100644
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@@ -1552,6 +1552,7 @@ mymain(void)
     DO_TEST("cpu-Haswell3", QEMU_CAPS_KVM);
     DO_TEST("cpu-Haswell-noTSX", QEMU_CAPS_KVM);
     DO_TEST("cpu-host-model-cmt", NONE);
+    DO_TEST("cpu-tsc-frequency", QEMU_CAPS_KVM);
     qemuTestSetHostCPU(driver.caps, NULL);
 
     DO_TEST("encrypted-disk", NONE);
-- 
2.47.2