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[Qemu-devel] [patch 09/10] qemu: handle vmstop from cpu context
From: |
Marcelo Tosatti |
Subject: |
[Qemu-devel] [patch 09/10] qemu: handle vmstop from cpu context |
Date: |
Wed, 25 Mar 2009 19:47:23 -0300 |
User-agent: |
quilt/0.47-1 |
There are certain cases where cpu context requests a vm stop, such as
-ENOSPC handling.
IMO its simpler to handle vmstop only through the iothread.
Note there is change in behaviour: now the cpu thread which requested vm_stop
will actually only stop when it exits back to cpu_main_loop. It might cause
further damage in between vmstop and cpu_main_loop.
Index: trunk/vl.c
===================================================================
--- trunk.orig/vl.c
+++ trunk/vl.c
@@ -3550,7 +3550,22 @@ void vm_start(void)
}
}
-void vm_stop(int reason)
+static int vmstop_requested;
+
+static int qemu_vmstop_requested(void)
+{
+ int r = vmstop_requested;
+ vmstop_requested = 0;
+ return r;
+}
+
+static void qemu_system_vmstop_request(int reason)
+{
+ vmstop_requested = reason;
+ main_loop_break();
+}
+
+static void __vm_stop(int reason)
{
if (vm_running) {
cpu_disable_ticks();
@@ -3560,6 +3575,21 @@ void vm_stop(int reason)
}
}
+void vm_stop(int reason)
+{
+ QemuThread me;
+ qemu_thread_self(&me);
+
+ if (!qemu_thread_equal(&me, &io_thread)) {
+ qemu_system_vmstop_request(reason);
+ /* make sure we can't return to cpu_exec */
+ if (cpu_single_env)
+ cpu_single_env->stop = 1;
+ return;
+ }
+ __vm_stop(reason);
+}
+
/* reset/shutdown handler */
typedef struct QEMUResetEntry {
@@ -3757,6 +3787,8 @@ static int cpu_can_run(CPUState *env)
return 0;
if (reset_requested)
return 0;
+ if (vmstop_requested)
+ return 0;
return 1;
}
@@ -4203,6 +4235,8 @@ static void qemu_init_state(void)
static void main_loop(void)
{
+ int r;
+
qemu_thread_self(&io_thread);
setup_iothread_fd();
@@ -4219,12 +4253,14 @@ static void main_loop(void)
no_shutdown = 0;
else
break;
- } else if (qemu_powerdown_requested())
+ } else if (qemu_powerdown_requested()) {
qemu_system_powerdown();
- else if (qemu_reset_requested()) {
+ } else if (qemu_reset_requested()) {
pause_all_vcpus();
qemu_system_reset();
resume_all_vcpus();
+ } else if ((r = qemu_vmstop_requested())) {
+ vm_stop(r);
}
}
}
- Re: [Qemu-devel] [patch 04/10] qemu: introduce main_loop_break, (continued)
[Qemu-devel] [patch 05/10] qemu: separate thread for io, Marcelo Tosatti, 2009/03/25
[Qemu-devel] [patch 07/10] qemu: handle reset/poweroff/shutdown in iothread, Marcelo Tosatti, 2009/03/25
[Qemu-devel] [patch 08/10] qemu: pause and resume cpu threads, Marcelo Tosatti, 2009/03/25
[Qemu-devel] [patch 09/10] qemu: handle vmstop from cpu context,
Marcelo Tosatti <=
[Qemu-devel] [patch 10/10] qemu: basic kvm iothread support, Marcelo Tosatti, 2009/03/25
Re: [Qemu-devel] [patch 00/10] iothread (candidate for inclusion), Blue Swirl, 2009/03/29