cpu: Honor vendor_id override in host-model

https://bugzilla.redhat.com/show_bug.cgi?id=858147

Signed-off-by: Jiri Denemark <jdenemar@redhat.com>

src/cpu/cpu_x86.c

@@ -2107,6 +2107,12 @@ x86UpdateHostModel(virCPUDefPtr guest,
     if (virCPUDefCopyModel(guest, host, true) < 0)
         goto cleanup;
 
+    if (oldguest->vendor_id) {
+        VIR_FREE(guest->vendor_id);
+        if (VIR_STRDUP(guest->vendor_id, oldguest->vendor_id) < 0)
+            goto cleanup;
+    }
+
     /* Remove non-migratable features by default
      * Note: this only works as long as no CPU model contains non-migratable
      * features directly */

tests/qemuxml2argvdata/qemuxml2argv-cpu-host-model-vendor.args

@@ -0,0 +1,20 @@
+LC_ALL=C \
+PATH=/bin \
+HOME=/home/test \
+USER=test \
+LOGNAME=test QEMU_AUDIO_DRV=none \
+/usr/bin/qemu \
+-S \
+-M pc \
+-cpu 'core2duo,vendor=Libvirt QEMU,+lahf_lm,+xtpr,+cx16,+tm2,+est,+vmx,\
++ds_cpl,+pbe,+tm,+ht,+ss,+acpi,+ds' \
+-m 214 \
+-smp 6 \
+-nographic \
+-monitor unix:/tmp/test-monitor,server,nowait \
+-no-acpi \
+-boot n \
+-usb \
+-net none \
+-serial none \
+-parallel none

tests/qemuxml2argvdata/qemuxml2argv-cpu-host-model-vendor.xml

@@ -0,0 +1,21 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219100</memory>
+  <currentMemory unit='KiB'>219100</currentMemory>
+  <vcpu placement='static'>6</vcpu>
+  <os>
+    <type arch='x86_64' machine='pc'>hvm</type>
+    <boot dev='network'/>
+  </os>
+  <cpu mode='host-model'>
+    <model vendor_id="Libvirt QEMU"/>
+  </cpu>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+      <emulator>/usr/bin/qemu</emulator>
+  </devices>
+</domain>

tests/qemuxml2argvtest.c

@@ -1245,6 +1245,7 @@ mymain(void)
                     QEMU_CAPS_OBJECT_MEMORY_RAM);
     DO_TEST_FAILURE("cpu-numa-memshared", QEMU_CAPS_SMP_TOPOLOGY);
     DO_TEST("cpu-host-model", NONE);
+    DO_TEST("cpu-host-model-vendor", NONE);
     skipLegacyCPUs = true;
     DO_TEST("cpu-host-model-fallback", NONE);
     DO_TEST_FAILURE("cpu-host-model-nofallback", NONE);