accel: Expose and register generic_handle_interrupt()

In order to dispatch over AccelOpsClass::handle_interrupt(),
we need it always defined, not calling a hidden handler under
the hood. Make AccelOpsClass::handle_interrupt() mandatory.
Expose generic_handle_interrupt() prototype and register it
for each accelerator.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <20250703173248.44995-29-philmd@linaro.org>

accel/hvf/hvf-accel-ops.c

@@ -353,6 +353,7 @@ static void hvf_accel_ops_class_init(ObjectClass *oc, const void *data)
 
     ops->create_vcpu_thread = hvf_start_vcpu_thread;
     ops->kick_vcpu_thread = hvf_kick_vcpu_thread;
+    ops->handle_interrupt = generic_handle_interrupt;
 
     ops->synchronize_post_reset = hvf_cpu_synchronize_post_reset;
     ops->synchronize_post_init = hvf_cpu_synchronize_post_init;

accel/kvm/kvm-accel-ops.c

@@ -101,6 +101,7 @@ static void kvm_accel_ops_class_init(ObjectClass *oc, const void *data)
     ops->synchronize_post_init = kvm_cpu_synchronize_post_init;
     ops->synchronize_state = kvm_cpu_synchronize_state;
     ops->synchronize_pre_loadvm = kvm_cpu_synchronize_pre_loadvm;
+    ops->handle_interrupt = generic_handle_interrupt;
 
 #ifdef TARGET_KVM_HAVE_GUEST_DEBUG
     ops->update_guest_debug = kvm_update_guest_debug_ops;

accel/qtest/qtest.c

@@ -67,6 +67,7 @@ static void qtest_accel_ops_class_init(ObjectClass *oc, const void *data)
     ops->create_vcpu_thread = dummy_start_vcpu_thread;
     ops->get_virtual_clock = qtest_get_virtual_clock;
     ops->set_virtual_clock = qtest_set_virtual_clock;
+    ops->handle_interrupt = generic_handle_interrupt;
 };
 
 static const TypeInfo qtest_accel_ops_type = {

accel/xen/xen-all.c

@@ -153,6 +153,7 @@ static void xen_accel_ops_class_init(ObjectClass *oc, const void *data)
     AccelOpsClass *ops = ACCEL_OPS_CLASS(oc);
 
     ops->create_vcpu_thread = dummy_start_vcpu_thread;
+    ops->handle_interrupt = generic_handle_interrupt;
 }
 
 static const TypeInfo xen_accel_ops_type = {

include/system/accel-ops.h

@@ -62,6 +62,7 @@ struct AccelOpsClass {
     void (*synchronize_pre_loadvm)(CPUState *cpu);
     void (*synchronize_pre_resume)(bool step_pending);
 
+    /* handle_interrupt is mandatory. */
     void (*handle_interrupt)(CPUState *cpu, int mask);
 
     /**
@@ -86,4 +87,6 @@ struct AccelOpsClass {
     void (*remove_all_breakpoints)(CPUState *cpu);
 };
 
+void generic_handle_interrupt(CPUState *cpu, int mask);
+
 #endif /* ACCEL_OPS_H */

system/cpus.c

@@ -254,7 +254,7 @@ int64_t cpus_get_elapsed_ticks(void)
     return cpu_get_ticks();
 }
 
-static void generic_handle_interrupt(CPUState *cpu, int mask)
+void generic_handle_interrupt(CPUState *cpu, int mask)
 {
     cpu->interrupt_request |= mask;
 
@@ -267,11 +267,7 @@ void cpu_interrupt(CPUState *cpu, int mask)
 {
     g_assert(bql_locked());
 
-    if (cpus_accel->handle_interrupt) {
-        cpus_accel->handle_interrupt(cpu, mask);
-    } else {
-        generic_handle_interrupt(cpu, mask);
-    }
+    cpus_accel->handle_interrupt(cpu, mask);
 }
 
 /*
@@ -680,6 +676,8 @@ void cpus_register_accel(const AccelOpsClass *ops)
 {
     assert(ops != NULL);
     assert(ops->create_vcpu_thread != NULL); /* mandatory */
+    assert(ops->handle_interrupt);
+
     cpus_accel = ops;
 }
 

target/i386/nvmm/nvmm-accel-ops.c

@@ -87,6 +87,7 @@ static void nvmm_accel_ops_class_init(ObjectClass *oc, const void *data)
 
     ops->create_vcpu_thread = nvmm_start_vcpu_thread;
     ops->kick_vcpu_thread = nvmm_kick_vcpu_thread;
+    ops->handle_interrupt = generic_handle_interrupt;
 
     ops->synchronize_post_reset = nvmm_cpu_synchronize_post_reset;
     ops->synchronize_post_init = nvmm_cpu_synchronize_post_init;

target/i386/whpx/whpx-accel-ops.c

@@ -90,6 +90,7 @@ static void whpx_accel_ops_class_init(ObjectClass *oc, const void *data)
     ops->create_vcpu_thread = whpx_start_vcpu_thread;
     ops->kick_vcpu_thread = whpx_kick_vcpu_thread;
     ops->cpu_thread_is_idle = whpx_vcpu_thread_is_idle;
+    ops->handle_interrupt = generic_handle_interrupt;
 
     ops->synchronize_post_reset = whpx_cpu_synchronize_post_reset;
     ops->synchronize_post_init = whpx_cpu_synchronize_post_init;