target/arm: call plugin trap callbacks

We recently introduced API for registering callbacks for trap related
events as well as the corresponding hook functions. Due to differences
between architectures, the latter need to be called from target specific
code.

This change places hooks for ARM (and Aarch64) targets. We decided to
treat the (V)IRQ, (VI/VF)NMI, (V)FIQ and VSERR exceptions as interrupts
since they are, presumably, async in nature.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Julian Ganz <neither@nut.email>
Message-ID: <20251027110344.2289945-13-alex.bennee@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

target/arm/helper.c

@@ -34,6 +34,7 @@
 #endif
 #include "cpregs.h"
 #include "target/arm/gtimer.h"
+#include "qemu/plugin.h"
 
 #define HELPER_H "tcg/helper.h"
 #include "exec/helper-proto.h.inc"
@@ -8783,6 +8784,24 @@ static void take_aarch32_exception(CPUARMState *env, int new_mode,
     }
 }
 
+void arm_do_plugin_vcpu_discon_cb(CPUState *cs, uint64_t from)
+{
+    switch (cs->exception_index) {
+    case EXCP_IRQ:
+    case EXCP_VIRQ:
+    case EXCP_NMI:
+    case EXCP_VINMI:
+    case EXCP_FIQ:
+    case EXCP_VFIQ:
+    case EXCP_VFNMI:
+    case EXCP_VSERR:
+        qemu_plugin_vcpu_interrupt_cb(cs, from);
+        break;
+    default:
+        qemu_plugin_vcpu_exception_cb(cs, from);
+    }
+}
+
 static void arm_cpu_do_interrupt_aarch32_hyp(CPUState *cs)
 {
     /*
@@ -9473,6 +9492,7 @@ void arm_cpu_do_interrupt(CPUState *cs)
     ARMCPU *cpu = ARM_CPU(cs);
     CPUARMState *env = &cpu->env;
     unsigned int new_el = env->exception.target_el;
+    uint64_t last_pc = cs->cc->get_pc(cs);
 
     assert(!arm_feature(env, ARM_FEATURE_M));
 
@@ -9489,6 +9509,7 @@ void arm_cpu_do_interrupt(CPUState *cs)
     if (tcg_enabled() && arm_is_psci_call(cpu, cs->exception_index)) {
         arm_handle_psci_call(cpu);
         qemu_log_mask(CPU_LOG_INT, "...handled as PSCI call\n");
+        qemu_plugin_vcpu_hostcall_cb(cs, last_pc);
         return;
     }
 
@@ -9500,6 +9521,7 @@ void arm_cpu_do_interrupt(CPUState *cs)
 #ifdef CONFIG_TCG
     if (cs->exception_index == EXCP_SEMIHOST) {
         tcg_handle_semihosting(cs);
+        qemu_plugin_vcpu_hostcall_cb(cs, last_pc);
         return;
     }
 #endif
@@ -9525,6 +9547,8 @@ void arm_cpu_do_interrupt(CPUState *cs)
     if (!kvm_enabled()) {
         cpu_set_interrupt(cs, CPU_INTERRUPT_EXITTB);
     }
+
+    arm_do_plugin_vcpu_discon_cb(cs, last_pc);
 }
 #endif /* !CONFIG_USER_ONLY */
 

target/arm/internals.h

@@ -375,6 +375,7 @@ static inline int r14_bank_number(int mode)
 
 void arm_cpu_register(const ARMCPUInfo *info);
 
+void arm_do_plugin_vcpu_discon_cb(CPUState *cs, uint64_t from);
 void register_cp_regs_for_features(ARMCPU *cpu);
 void init_cpreg_list(ARMCPU *cpu);
 

target/arm/tcg/m_helper.c

@@ -23,6 +23,7 @@
 #if !defined(CONFIG_USER_ONLY)
 #include "hw/intc/armv7m_nvic.h"
 #endif
+#include "qemu/plugin.h"
 
 static void v7m_msr_xpsr(CPUARMState *env, uint32_t mask,
                          uint32_t reg, uint32_t val)
@@ -2194,6 +2195,7 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs)
     CPUARMState *env = &cpu->env;
     uint32_t lr;
     bool ignore_stackfaults;
+    uint64_t last_pc = env->regs[15];
 
     arm_log_exception(cs);
 
@@ -2361,6 +2363,7 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs)
         g_assert_not_reached();
 #endif
         env->regs[15] += env->thumb ? 2 : 4;
+        qemu_plugin_vcpu_hostcall_cb(cs, last_pc);
         return;
     case EXCP_BKPT:
         armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_DEBUG, false);
@@ -2427,6 +2430,8 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs)
 
     ignore_stackfaults = v7m_push_stack(cpu);
     v7m_exception_taken(cpu, lr, false, ignore_stackfaults);
+
+    arm_do_plugin_vcpu_discon_cb(cs, last_pc);
 }
 
 uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg)