accel/tcg: Make cpu_exec_interrupt hook mandatory

The TCGCPUOps::cpu_exec_interrupt hook is currently not mandatory; if
it is left NULL then we treat it as if it had returned false. However
since pretty much every architecture needs to handle interrupts,
almost every target we have provides the hook. The one exception is
Tricore, which doesn't currently implement the architectural
interrupt handling.

Add a "do nothing" implementation of cpu_exec_hook for Tricore,
assert on startup that the CPU does provide the hook, and remove
the runtime NULL check before calling it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20240712113949.4146855-1-peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

accel/tcg/cpu-exec.c

@@ -857,8 +857,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
         else {
             const TCGCPUOps *tcg_ops = cpu->cc->tcg_ops;
 
-            if (tcg_ops->cpu_exec_interrupt &&
-                tcg_ops->cpu_exec_interrupt(cpu, interrupt_request)) {
+            if (tcg_ops->cpu_exec_interrupt(cpu, interrupt_request)) {
                 if (!tcg_ops->need_replay_interrupt ||
                     tcg_ops->need_replay_interrupt(interrupt_request)) {
                     replay_interrupt();
@@ -1080,6 +1079,7 @@ bool tcg_exec_realizefn(CPUState *cpu, Error **errp)
         /* Check mandatory TCGCPUOps handlers */
 #ifndef CONFIG_USER_ONLY
         assert(cpu->cc->tcg_ops->cpu_exec_halt);
+        assert(cpu->cc->tcg_ops->cpu_exec_interrupt);
 #endif /* !CONFIG_USER_ONLY */
         cpu->cc->tcg_ops->initialize();
         tcg_target_initialized = true;

target/tricore/cpu.c

@@ -155,6 +155,11 @@ static void tc37x_initfn(Object *obj)
     set_feature(&cpu->env, TRICORE_FEATURE_162);
 }
 
+static bool tricore_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
+{
+    /* Interrupts are not implemented */
+    return false;
+}
 
 #include "hw/core/sysemu-cpu-ops.h"
 
@@ -169,6 +174,7 @@ static const TCGCPUOps tricore_tcg_ops = {
     .synchronize_from_tb = tricore_cpu_synchronize_from_tb,
     .restore_state_to_opc = tricore_restore_state_to_opc,
     .tlb_fill = tricore_cpu_tlb_fill,
+    .cpu_exec_interrupt = tricore_cpu_exec_interrupt,
     .cpu_exec_halt = tricore_cpu_has_work,
 };