Re: [Qemu-devel] [PATCH] virtio-serial-bus: replay guest_open on migration

[Markus Armbruster <armbru@redhat.com>]

Alon Levy <alevy@redhat.com> writes:

> On Wed, Jul 27, 2011 at 07:45:25AM +0200, Markus Armbruster wrote:
>> Alon Levy <alevy@redhat.com> writes:
>> 
>> > Signed-off-by: Alon Levy <alevy@redhat.com>
>> > ---
>> >  hw/virtio-serial-bus.c |    8 +++++++-
>> >  1 files changed, 7 insertions(+), 1 deletions(-)
>> >
>> > diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
>> > index c5eb931..7a652ff 100644
>> > --- a/hw/virtio-serial-bus.c
>> > +++ b/hw/virtio-serial-bus.c
>> > @@ -618,14 +618,20 @@ static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
>> >      for (i = 0; i < nr_active_ports; i++) {
>> >          uint32_t id;
>> >          bool host_connected;
>> > +        VirtIOSerialPortInfo *info;
>> >  
>> >          id = qemu_get_be32(f);
>> >          port = find_port_by_id(s, id);
>> >          if (!port) {
>> >              return -EINVAL;
>> >          }
>> > -
>> >          port->guest_connected = qemu_get_byte(f);
>> > +        info = DO_UPCAST(VirtIOSerialPortInfo, qdev, port->dev.info);
>> > +        if (port->guest_connected && info->guest_open) {
>> > +            /* replay guest open */
>> > +            info->guest_open(port);
>> > +
>> > +        }
>> >          host_connected = qemu_get_byte(f);
>> >          if (host_connected != port->host_connected) {
>> >              /*
>> 
>> The patch makes enough sense to me, but the commit message is
>> insufficient.  Why do you have to replay?  And what's being fixed?
>
> When migrating a host with with a spice agent running the mouse becomes
> non operational after the migration. This is rhbz #718463, currently on
> spice-server but it seems this is a qemu-kvm issue. The problem is that
> after migration spice doesn't know the guest agent is open. Spice is just
> a char dev here. And a chardev cannot query it's device, the device has
> to let the chardev know when it is open. Right now after migration the
> chardev which is recreated is in it's default state, which assumes the
> guest is disconnected. Char devices carry no information across migration,
> but the virtio-serial does already carry the guest_connected state. This
> patch passes that bit to the chardev.

Put this information in the commit message and resend?