On Fri, Apr 9, 2010 at 10:20 PM, Luiz Capitulino <lcapitul...@redhat.com> wrote: > On Fri, 9 Apr 2010 18:32:21 +0900 > Jun Koi <junkoi2...@gmail.com> wrote: > >> Hi, >> >> I found something very funny happening with 0.12.3: it seems the VM is >> still running even I already stopped it. >> >> Here is how I verified that: Boot any OS (I checked with Windows XP >> and Ubuntu) with 0.12.3, and stop it any time after it booted up. Use >> "stop" command on monitor interface. >> >> Now the VM stops. Then in the same monitor interface, run "info >> registers" again and again. You can see that the value of EIP and >> EFLAGS still change once in a while. This should not happen, becaues >> the VM already stopped. >> >> I checked, and dont see this problem with 0.11.1. And this doesnt >> happen with the latest code in the git tree, either. >> >> Any idea on why this happens??? > > Can you try commit 55274a305 ? If it fixes the problem we need it > in stable, if it doesn't you can try to find the fix by using git bisect. >
This hint makes sense, but the point is that I tried with some commits before that 55274a305, and didnt see the problem. Still I am not sure the problem is already fixed before 55274a305, or I am just unlucky enough not see the problem when testing. After bisecting, I can say that the culprit is the below patch, from Marcelo. Now I am wondering if the above commit 55274a305 of Paolo Bonzini fixed the bug, or other commit before that?? We should find the correct fix, and port it to 0.12.4. Thanks, J commit 535d2eb34a0f1908dc694c51ce8d4ec6dccc7807 Author: Marcelo Tosatti <mtosa...@redhat.com> Date: Tue Feb 9 12:49:04 2010 -0200 iothread: fix vcpu stop with smp tcg Round robin vcpus in tcg_cpu_next even if the vm stopped. This allows all cpus to enter stopped state. Signed-off-by: Marcelo Tosatti <mtosa...@redhat.com> Signed-off-by: Anthony Liguori <aligu...@us.ibm.com> (cherry picked from commit c37cc7b072fa4ca8d8d21ac31d26baff5f47f9f9) diff --git a/vl.c b/vl.c index 007709a..3b5a8e0 100644 --- a/vl.c +++ b/vl.c @@ -4042,14 +4042,15 @@ static void tcg_cpu_exec(void) for (; next_cpu != NULL; next_cpu = next_cpu->next_cpu) { CPUState *env = cur_cpu = next_cpu; - if (!vm_running) - break; if (timer_alarm_pending) { timer_alarm_pending = 0; break; } if (cpu_can_run(env)) ret = qemu_cpu_exec(env); + else if (env->stop) + break; + if (ret == EXCP_DEBUG) { gdb_set_stop_cpu(env); debug_requested = 1;