Re: [PATCH] Qemu-xen: HVM S3 bugfix

[Anthony PERARD <anthony.perard@citrix.com>]

On 13/08/13 15:15, Liu, Jinsong wrote:
> From fc928436df17673bfea1d902859c682c99c1489d Mon Sep 17 00:00:00 2001
> From: Liu Jinsong <jinsong.liu@intel.com>
> Date: Wed, 14 Aug 2013 05:26:56 +0800
> Subject: [PATCH] Qemu-xen: HVM S3 bugfix
> 
> This patch is used to fix HVM S3 bug caused from the difference
> between qemu-traditioanl and standard qemu (which qemu-xen stems from).
> For qemu-traditional, hvm s3 resumes via 'xl trigger' command interface.
> For standard qemu, hvm s3 resumes via keyboard triggering.
> 
> So currently for qemu-xen, both 'xl' interface and keyboard triggering
> hvm s3 cannot work. 'xl' interface didn't reset ioemu devices, while
> keyboard triggering didn't unpause hvm domain.
> 
> This patch fixes the bug. It keeps compatible w/ current xen 'xl' interface,
> by moving qemu system reset logic forward to qemu suspend.
> 
> Signed-off-by: Liu Jinsong <jinsong.liu@intel.com>
> ---
>  vl.c |   25 ++++++++++++++++---------
>  1 files changed, 16 insertions(+), 9 deletions(-)
> 
> diff --git a/vl.c b/vl.c
> index 5314f55..deea92c 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -1619,10 +1619,15 @@ void qemu_system_reset_request(void)
>  
>  static void qemu_system_suspend(void)
>  {
> -    pause_all_vcpus();
> -    notifier_list_notify(&suspend_notifiers, NULL);
> -    runstate_set(RUN_STATE_SUSPENDED);
> -    monitor_protocol_event(QEVENT_SUSPEND, NULL);
> +    if (!xen_enabled()) {
> +        pause_all_vcpus();
> +        notifier_list_notify(&suspend_notifiers, NULL);
> +        runstate_set(RUN_STATE_SUSPENDED);
> +        monitor_protocol_event(QEVENT_SUSPEND, NULL);
> +    } else {
> +        notifier_list_notify(&suspend_notifiers, NULL);
> +        qemu_system_reset(VMRESET_SILENT);
> +    }
>  }
>  
>  void qemu_system_suspend_request(void)
> @@ -1740,11 +1745,13 @@ static bool main_loop_should_exit(void)
>          }
>      }
>      if (qemu_wakeup_requested()) {
> -        pause_all_vcpus();
> -        cpu_synchronize_all_states();
> -        qemu_system_reset(VMRESET_SILENT);
> -        resume_all_vcpus();
> -        monitor_protocol_event(QEVENT_WAKEUP, NULL);
> +        if (!xen_enabled()) {
> +            pause_all_vcpus();
> +            cpu_synchronize_all_states();
> +            qemu_system_reset(VMRESET_SILENT);
> +            resume_all_vcpus();
> +            monitor_protocol_event(QEVENT_WAKEUP, NULL);
> +        }
>      }
>      if (qemu_powerdown_requested()) {
>          qemu_system_powerdown();

Hi,

I don't think changing vl.c is a good idee for this.

Could you try to use a QMP command instead ? Look for the QMP command
"system_wakeup", it's probably what's needed to be called on qemu-xen.

A simple way to test this would be to call the QMP command manually with
QMP/qmp present in the qemu tree.
$ ./QMP/qmp --path=/run/xen/qmp-libxl-$domid system_wakeup

-- 
Anthony PERARD