Re: [PATCH] ui: fix spice display regression

[Marc-André Lureau]

Hi

On Wed, Jan 27, 2021 at 2:03 PM <marcandre.lureau@redhat.com> wrote:
>
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>
> Since commit b4e1a342112e50e05b609e857f38c1f2b7aafdc4 ("vl: remove
> separate preconfig main_loop"), spice initialization is a bit dodgy, and
> the client get stuck waiting for server events.
>
> The initialization order changed, so that qemu_spice_display_start() is
> called before the display interfaces are added. The new interfaces
> aren't started by spice-server automatically (yet?), so we have to tell
> the server explicitely when we are already running.
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  ui/spice-core.c | 10 +++++++++-
>  1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/ui/spice-core.c b/ui/spice-core.c
> index 5746d0aae7..6eebf12e3c 100644
> --- a/ui/spice-core.c
> +++ b/ui/spice-core.c
> @@ -830,6 +830,8 @@ static void qemu_spice_init(void)
>
>  static int qemu_spice_add_interface(SpiceBaseInstance *sin)
>  {
> +    int ret;
> +
>      if (!spice_server) {
>          if (QTAILQ_FIRST(&qemu_spice_opts.head) != NULL) {
>              error_report("Oops: spice configured but not active");
> @@ -848,7 +850,13 @@ static int qemu_spice_add_interface(SpiceBaseInstance 
> *sin)
>          qemu_add_vm_change_state_handler(vm_change_state_handler, NULL);
>      }
>
> -    return spice_server_add_interface(spice_server, sin);
> +    ret = spice_server_add_interface(spice_server, sin);
> +    /* make sure the newly added interface is started */
> +    if (ret == 0 && spice_display_is_running) {
> +        spice_server_vm_start(spice_server);
> +    }
> +
> +    return ret;
>  }
>
>  static GSList *spice_consoles;
> --
> 2.29.0
>
>

Oops, it doesn't work reliably. There is some race in spice server now.

spice_server_vm_start() sends RED_WORKER_MESSAGE_START to the QXL
worker thread. But if two of those come, it will assert... It should
probably not, I will send a patch to spice.

I am looking for other options for QEMU though.

-- 
Marc-André Lureau