[PATCH 28/37] Move debug exception handling out of cpu_exec

Marcelo Tosatti
2011-02-14T15:25:00Z

To prepare splitting up KVM and TCG CPU entry/exit, move the debug
exception into cpus.c and invoke cpu_handle_debug_exception on return
from qemu_cpu_exec.

This also allows to clean up the debug request signaling: We can assign
the job of informing main-loop to qemu_system_debug_request and stop the
calling cpu directly in cpu_handle_debug_exception. That means a debug
stop will now only be signaled via debug_requested and not additionally
via vmstop_requested.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---
cpu-exec.c | 24 ------------------------
cpus.c | 35 ++++++++++++++++++++++++++++++-----
vl.c | 2 +-
3 files changed, 31 insertions(+), 30 deletions(-)

diff --git a/cpu-exec.c b/cpu-exec.c
index 8c9fb8b..9c0b10d 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -196,28 +196,6 @@ static inline TranslationBlock *tb_find_fast(void)
return tb;
}

-static CPUDebugExcpHandler *debug_excp_handler;
-
-CPUDebugExcpHandler *cpu_set_debug_excp_handler(CPUDebugExcpHandler *handler)
-{
- CPUDebugExcpHandler *old_handler = debug_excp_handler;
-
- debug_excp_handler = handler;
- return old_handler;
-}
-
-static void cpu_handle_debug_exception(CPUState *env)
-{
- CPUWatchpoint *wp;
-
- if (!env->watchpoint_hit)
- QTAILQ_FOREACH(wp, &env->watchpoints, entry)
- wp->flags &= ~BP_WATCHPOINT_HIT;
-
- if (debug_excp_handler)
- debug_excp_handler(env);
-}
-
/* main execution loop */

volatile sig_atomic_t exit_request;
@@ -287,8 +265,6 @@ int cpu_exec(CPUState *env1)
if (env->exception_index >= EXCP_INTERRUPT) {
/* exit request from the cpu execution loop */
ret = env->exception_index;
- if (ret == EXCP_DEBUG)
- cpu_handle_debug_exception(env);
break;
} else {
#if defined(CONFIG_USER_ONLY)
diff --git a/cpus.c b/cpus.c
index 97a6d4f..c7e86c2 100644
--- a/cpus.c
+++ b/cpus.c
@@ -165,10 +165,34 @@ static bool all_cpu_threads_idle(void)
return true;
}

-static void cpu_debug_handler(CPUState *env)
+static CPUDebugExcpHandler *debug_excp_handler;
+
+CPUDebugExcpHandler *cpu_set_debug_excp_handler(CPUDebugExcpHandler *handler)
+{
+ CPUDebugExcpHandler *old_handler = debug_excp_handler;
+
+ debug_excp_handler = handler;
+ return old_handler;
+}
+
+static void cpu_handle_debug_exception(CPUState *env)
{
+ CPUWatchpoint *wp;
+
+ if (!env->watchpoint_hit) {
+ QTAILQ_FOREACH(wp, &env->watchpoints, entry) {
+ wp->flags &= ~BP_WATCHPOINT_HIT;
+ }
+ }
+ if (debug_excp_handler) {
+ debug_excp_handler(env);
+ }
+
gdb_set_stop_cpu(env);
qemu_system_debug_request();
+#ifdef CONFIG_IOTHREAD
+ env->stopped = 1;
+#endif
}

#ifdef CONFIG_LINUX
@@ -479,7 +503,6 @@ int qemu_init_main_loop(void)
return ret;
}
#endif
- cpu_set_debug_excp_handler(cpu_debug_handler);

qemu_init_sigbus();

@@ -653,8 +676,6 @@ int qemu_init_main_loop(void)
int ret;
sigset_t blocked_signals;

- cpu_set_debug_excp_handler(cpu_debug_handler);
-
qemu_init_sigbus();

blocked_signals = block_io_signals();
@@ -808,7 +829,10 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)

while (1) {
if (cpu_can_run(env)) {
- qemu_cpu_exec(env);
+ r = qemu_cpu_exec(env);
+ if (r == EXCP_DEBUG) {
+ cpu_handle_debug_exception(env);
+ }
}
qemu_kvm_wait_io_event(env);
}
@@ -1076,6 +1100,7 @@ bool cpu_exec_all(void)
qemu_kvm_eat_signals(env);
}
if (r == EXCP_DEBUG) {
+ cpu_handle_debug_exception(env);
break;
}
} else if (env->stop) {
diff --git a/vl.c b/vl.c
index eebe684..b436952 100644
--- a/vl.c
+++ b/vl.c
@@ -1315,7 +1315,7 @@ void qemu_system_powerdown_request(void)
void qemu_system_debug_request(void)
{
debug_requested = 1;
- vm_stop(VMSTOP_DEBUG);
+ qemu_notify_event();
}

void qemu_system_vmstop_request(int reason)
--
1.7.4