Re: [Qemu-devel] [PATCH V3 06/14] virtio-serial-bus: switch to bus specific queue limit

[Jason Wang <jasowang@redhat.com>]

On Fri, Mar 6, 2015 at 8:27 PM, Cornelia Huck 
<cornelia.huck@de.ibm.com> wrote:
> On Thu,  5 Mar 2015 13:48:43 +0800
> Jason Wang <jasowang@redhat.com> wrote:
> 
>>  Cc: Amit Shah <amit.shah@redhat.com>
>>  Signed-off-by: Jason Wang <jasowang@redhat.com>
>>  ---
>>   hw/char/virtio-serial-bus.c | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>  
>>  diff --git a/hw/char/virtio-serial-bus.c 
>> b/hw/char/virtio-serial-bus.c
>>  index 37a6f44..f280e95 100644
>>  --- a/hw/char/virtio-serial-bus.c
>>  +++ b/hw/char/virtio-serial-bus.c
>>  @@ -26,6 +26,8 @@
>>   #include "hw/virtio/virtio-serial.h"
>>   #include "hw/virtio/virtio-access.h"
>>  
>>  +#define VIRTIO_SERIAL_BUS_QUEUE_MAX 64
>>  +
>>   struct VirtIOSerialDevices {
>>       QLIST_HEAD(, VirtIOSerial) devices;
>>   } vserdevices;
>>  @@ -942,7 +944,7 @@ static void 
>> virtio_serial_device_realize(DeviceState *dev, Error **errp)
>>       }
>>  
>>       /* Each port takes 2 queues, and one pair is for the control 
>> queue */
>>  -    max_supported_ports = VIRTIO_PCI_QUEUE_MAX / 2 - 1;
>>  +    max_supported_ports = VIRTIO_SERIAL_BUS_QUEUE_MAX / 2 - 1;
> 
> Shouldn't this be determined via the VirtIODevice instead? Or be the
> maximum of those two values?

Rethink about this. I think it's ok to use the transport limit through 
VirtIODevice here. Then there's no need for virtio serial to handle 
migration compatibility.