On Wed, Jul 08, 2020 at 06:50:12PM +0200, Cornelia Huck wrote:
> On Wed, 8 Jul 2020 14:05:26 +0100
> Stefan Hajnoczi <stefa...@redhat.com> wrote:
> 
> > On Tue, Jul 07, 2020 at 05:44:53PM +0200, Cornelia Huck wrote:
> > > On Mon,  6 Jul 2020 14:56:48 +0100
> > > Stefan Hajnoczi <stefa...@redhat.com> wrote:
> 
> > > > diff --git a/hw/virtio/virtio-scsi-pci.c b/hw/virtio/virtio-scsi-pci.c
> > > > index 3ff9eb7ef6..fa4b3bfb50 100644
> > > > --- a/hw/virtio/virtio-scsi-pci.c
> > > > +++ b/hw/virtio/virtio-scsi-pci.c
> > > > @@ -46,13 +46,17 @@ static void virtio_scsi_pci_realize(VirtIOPCIProxy 
> > > > *vpci_dev, Error **errp)
> > > >  {
> > > >      VirtIOSCSIPCI *dev = VIRTIO_SCSI_PCI(vpci_dev);
> > > >      DeviceState *vdev = DEVICE(&dev->vdev);
> > > > -    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev);
> > > >      DeviceState *proxy = DEVICE(vpci_dev);
> > > > +    VirtIOSCSIConf *conf = &dev->vdev.parent_obj.conf;
> > > >      char *bus_name;
> > > >  
> > > > +    if (conf->num_queues == VIRTIO_SCSI_AUTO_NUM_QUEUES) {
> > > > +        conf->num_queues =
> > > > +            virtio_pci_optimal_num_queues(VIRTIO_SCSI_VQ_NUM_FIXED);
> > > > +    }
> > > > +
> > > >      if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) {
> > > > -        vpci_dev->nvectors = vs->conf.num_queues +
> > > > -                             VIRTIO_SCSI_VQ_NUM_FIXED + 1;
> > > > +        vpci_dev->nvectors = conf->num_queues + 
> > > > VIRTIO_SCSI_VQ_NUM_FIXED + 1;
> > > >      }
> > > >  
> > > >      /*  
> > > 
> > > One corner case where the setup may end up being a bit odd is a
> > > situation where nvectors was specified, but num_queues was not, and the
> > > device suddenly ends up with more queues than vectors. But I don't see
> > > a reason why you would want to specify nvectors but not num_queues in a
> > > real word scenario, so I think we can ignore that corner case.  
> > 
> > I agree, I've ignored that case. Other options include printing a
> > warning or even an error when num_queues disagrees with nvectors.
> 
> I think an error would be too harsh, but a warning sounds useful.

I'll send this as a separate patch because at least virtio-serial is
also affected.

Stefan

Attachment: signature.asc
Description: PGP signature

Reply via email to