[PATCH 15/16] target/mips/cpu: Do not allow system-mode use without input clock

[Philippe Mathieu-Daudé]

Now than all QOM users provides the input clock, do not allow
using a CPU core without its input clock connected on system-mode
emulation. For user-mode, keep providing a fixed 200 MHz clock,
as it used by the RDHWR instruction (see commit cdfcad788394).

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
Cc: Igor Mammedov <imammedo@redhat.com>

We need the qtest check for tests/qtest/machine-none-test.c
which instanciate a CPU with the none machine. Igor, is it
better to remove the MIPS targets from the test cpus_map[]?
---
 target/mips/cpu.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/target/mips/cpu.c b/target/mips/cpu.c
index 2f75216c324..cc4ee75af30 100644
--- a/target/mips/cpu.c
+++ b/target/mips/cpu.c
@@ -25,6 +25,7 @@
 #include "kvm_mips.h"
 #include "qemu/module.h"
 #include "sysemu/kvm.h"
+#include "sysemu/qtest.h"
 #include "exec/exec-all.h"
 #include "hw/qdev-clock.h"
 #include "hw/qdev-properties.h"
@@ -159,11 +160,18 @@ static void mips_cpu_realizefn(DeviceState *dev, Error 
**errp)
     Error *local_err = NULL;
 
     if (!clock_get(cs->clock)) {
+#ifdef CONFIG_USER_ONLY
         /*
          * Initialize the frequency to 200MHz in case
          * the clock remains unconnected.
          */
         clock_set_hz(cs->clock, 200000000);
+#else
+        if (!qtest_enabled()) {
+            error_setg(errp, "CPU clock must be connected to a clock source");
+            return;
+        }
+#endif
     }
     mips_cpu_clk_update(cs);
 
-- 
2.26.2