[PATCH 01/27] cpus: Add helper to log raised exceptions with '-d int'

["Philippe Mathieu-Daudé" <philmd@oss.qualcomm.com>]

Add log_raise_exception(), a common helper cpu_loop_*() can
call to log a raised exception when '-d int' is used, and
qemu_excp_name() to resolve QEMU-internal exceptions to names.

Use it in cpu_loop_exit_atomic() to log the EXCP_ATOMIC reason.

Signed-off-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
---
 accel/tcg/cpu-exec-common.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/accel/tcg/cpu-exec-common.c b/accel/tcg/cpu-exec-common.c
index 68077c8fd9d..2ac8380d0bb 100644
--- a/accel/tcg/cpu-exec-common.c
+++ b/accel/tcg/cpu-exec-common.c
@@ -89,6 +89,37 @@ void tcg_update_all_cflags(void)
     }
 }
 
+#define EXCP_QEMU_INTERNAL 0x10000
+
+static const char *qemu_excp_name(int excp)
+{
+    static const char *excp_name[] = {
+        [EXCP_INTERRUPT - EXCP_QEMU_INTERNAL] = "async interruption",
+        [EXCP_HLT       - EXCP_QEMU_INTERNAL] = "hlt instruction",
+        [EXCP_DEBUG     - EXCP_QEMU_INTERNAL] = "debug",
+        [EXCP_HALTED    - EXCP_QEMU_INTERNAL] = "halted",
+        [EXCP_YIELD     - EXCP_QEMU_INTERNAL] = "yield",
+        [EXCP_ATOMIC    - EXCP_QEMU_INTERNAL] = "emulate atomic",
+    };
+    assert(excp >= EXCP_QEMU_INTERNAL);
+    excp -= EXCP_QEMU_INTERNAL;
+    if ((excp < ARRAY_SIZE(excp_name)) && excp_name[excp]) {
+        return excp_name[excp];
+    }
+    return "undocumented";
+}
+
+static void log_raise_exception(const CPUState *cpu, int excp)
+{
+    if (!qemu_loglevel_mask(CPU_LOG_INT)) {
+        return;
+    }
+    if (excp >= EXCP_QEMU_INTERNAL) {
+        qemu_log_mask(CPU_LOG_INT, "raise exception: 0x%x (internal: %s)\n",
+                                   excp, qemu_excp_name(excp));
+    }
+}
+
 /* exit the current TB, but without causing any exception to be raised */
 void cpu_loop_exit_noexc(CPUState *cpu)
 {
@@ -118,5 +149,6 @@ void cpu_loop_exit_atomic(CPUState *cpu, uintptr_t pc)
     /* Prevent looping if already executing in a serial context. */
     g_assert(!cpu_in_serial_context(cpu));
     cpu->exception_index = EXCP_ATOMIC;
+    log_raise_exception(cpu, EXCP_ATOMIC);
     cpu_loop_exit_restore(cpu, pc);
 }
-- 
2.55.0