Re: [Qemu-devel] [PATCH V7 08/16] virtio: introduce bus specific queue limit

[Jason Wang <jasowang@redhat.com>]

On Tue, Apr 28, 2015 at 1:13 PM, Michael S. Tsirkin <mst@redhat.com> 
wrote:
> On Tue, Apr 28, 2015 at 11:14:04AM +0800, Jason Wang wrote:
>>  
>>  
>>  On Mon, Apr 27, 2015 at 7:05 PM, Michael S. Tsirkin 
>> <mst@redhat.com> wrote:
>>  >On Thu, Apr 23, 2015 at 02:21:41PM +0800, Jason Wang wrote:
>>  >> This patch introduces a bus specific queue limitation. It will be
>>  >> useful for increasing the limit for one of the bus without 
>> disturbing
>>  >> other buses.
>>  >> Cc: Michael S. Tsirkin <mst@redhat.com>
>>  >> Cc: Alexander Graf <agraf@suse.de>
>>  >> Cc: Richard Henderson <rth@twiddle.net>
>>  >> Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
>>  >> Cc: Christian Borntraeger <borntraeger@de.ibm.com>
>>  >> Cc: Paolo Bonzini <pbonzini@redhat.com>
>>  >> Signed-off-by: Jason Wang <jasowang@redhat.com>
>>  >> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
>>  >
>>  >Is this still needed if you drop the attempt to
>>  >keep the limit around for old machine types?
>>  
>>  If we agree to drop, we probably need transport specific macro.
> 
> You mean just rename VIRTIO_PCI_QUEUE_MAX to VIRTIO_QUEUE_MAX?
> Fine, why not.

I mean keeping VIRTIO_PCI_QUEUE_MAX for pci only and just increase pci 
limit. And introduce e.g VIRTIO_PCI_QUEUE_CCW for ccw and keep it as 
64. Since to my understanding, it's not safe to increase the limit for 
all other transports which was pointed out by Cornelia in V1: 
http://permalink.gmane.org/gmane.comp.emulators.qemu/318245.