Re: [Qemu-devel] [PATCH V4 09/19] virito: introduce bus specific queue limit

[Cornelia Huck <cornelia.huck@de.ibm.com>]

On Wed, 18 Mar 2015 17:34:59 +0800
Jason Wang <jasowang@redhat.com> wrote:

Typo in subject: s/virito/virtio/

> 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>
> ---
>  hw/char/virtio-serial-bus.c    |  2 +-
>  hw/net/virtio-net.c            |  4 ++--
>  hw/s390x/s390-virtio-bus.c     |  1 +
>  hw/s390x/virtio-ccw.c          |  1 +
>  hw/scsi/virtio-scsi.c          |  4 ++--
>  hw/virtio/virtio-mmio.c        |  1 +
>  hw/virtio/virtio-pci.c         |  1 +
>  hw/virtio/virtio.c             | 40 +++++++++++++++++++++++++---------------
>  include/hw/virtio/virtio-bus.h |  1 +
>  include/hw/virtio/virtio.h     |  1 +
>  10 files changed, 36 insertions(+), 20 deletions(-)

> diff --git a/hw/s390x/s390-virtio-bus.c b/hw/s390x/s390-virtio-bus.c
> index 047c963..2b41e32 100644
> --- a/hw/s390x/s390-virtio-bus.c
> +++ b/hw/s390x/s390-virtio-bus.c
> @@ -715,6 +715,7 @@ static void virtio_s390_bus_class_init(ObjectClass *klass, void *data)
>      bus_class->max_dev = 1;
>      k->notify = virtio_s390_notify;
>      k->get_features = virtio_s390_get_features;
> +    k->queue_max = VIRTIO_PCI_QUEUE_MAX;

I'm wondering whether we should initialize queue_max to smth like
VIRTIO_QUEUE_MAX_DEFAULT (== 64) in virtio-bus.c instead and have the
individual classes override that value once they want to use a
different value?

But I'm fine with this patch as it stands as well.

>  }