[PATCH v2] qemu: Do not silently allow non-available timers on non-x86 systems

[Thomas Huth]

libvirt currently silently allows <timer name="kvmclock"/> and some
other timer tags in the guest XML definition for timers that do not
exist on non-x86 systems. We should not silently ignore these tags
since the users might not get what they expected otherwise.
Note: The error is only generated if the timer is marked with
present="yes" - otherwise we would suddenly refuse XML definitions
that worked without problems before.

Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1754887
Signed-off-by: Thomas Huth <thuth at redhat.com>
---
 v2: Check also for timer->present == 1

 src/qemu/qemu_validate.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/qemu/qemu_validate.c b/src/qemu/qemu_validate.c
index 488f258d00..561e7b12c7 100644
--- a/src/qemu/qemu_validate.c
+++ b/src/qemu/qemu_validate.c
@@ -371,6 +371,18 @@ qemuValidateDomainDefClockTimers(const virDomainDef *def,
         case VIR_DOMAIN_TIMER_NAME_TSC:
         case VIR_DOMAIN_TIMER_NAME_KVMCLOCK:
         case VIR_DOMAIN_TIMER_NAME_HYPERVCLOCK:
+            if (!ARCH_IS_X86(def->os.arch) && timer->present == 1) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                               _("Configuring the '%s' timer is not supported "
+                                 "for virtType=%s arch=%s machine=%s guests"),
+                               virDomainTimerNameTypeToString(timer->name),
+                               virDomainVirtTypeToString(def->virtType),
+                               virArchToString(def->os.arch),
+                               def->os.machine);
+                return -1;
+            }
+            break;
+
         case VIR_DOMAIN_TIMER_NAME_LAST:
             break;
 
-- 
2.18.1