Re: [Qemu-block] [Qemu-devel] [PATCH v4 1/1] virtio-scsi-ccw: use ioeventfd even when KVM is disabled

[QingFeng Hao]

在 2017/7/4 22:04, Christian Borntraeger 写道:
> On 07/04/2017 03:23 PM, QingFeng Hao wrote:
> > This patch is based on a similar patch from Stefan Hajnoczi -
> > commit c324fd0a39c ("virtio-pci: use ioeventfd even when KVM is disabled")
> >
> > Do not check kvm_eventfds_enabled() when KVM is disabled since it
> > always returns 0.  Since commit 8c56c1a592b5092d91da8d8943c17777d6462a6f
> > ("memory: emulate ioeventfd") it has been possible to use ioeventfds in
> > qtest or TCG mode.
> >
> > This patch makes -device virtio-scsi-ccw,iothread=iothread0 work even
> > when KVM is disabled.
> > Currently we don't have an equivalent to "memory: emulate ioeventfd"
> > for ccw yet, but that this doesn't hurt and qemu-iotests 068 can pass with
> > skipping iothread arguments.
> >
> > I have tested that virtio-scsi-ccw works under tcg both with and without
> > iothread.
> >
> > This patch fixes qemu-iotests 068, which was accidentally merged early
> > despite the dependency on ioeventfd.
> >
> > Signed-off-by: QingFeng Hao <address@hidden>
> > Reviewed-by: Cornelia Huck <address@hidden>
> I will take it via the s390-next tree.
>
> thanks applied.
Ok, thanks.
> > ---
> >   hw/s390x/virtio-ccw.c | 2 +-
> >   target/s390x/cpu.h    | 6 +++++-
> >   2 files changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> > index 90d37cb9ff..35896eb007 100644
> > --- a/hw/s390x/virtio-ccw.c
> > +++ b/hw/s390x/virtio-ccw.c
> > @@ -711,7 +711,7 @@ static void virtio_ccw_device_realize(VirtioCcwDevice *dev, 
> > Error **errp)
> >           sch->cssid, sch->ssid, sch->schid, sch->devno,
> >           ccw_dev->devno.valid ? "user-configured" : "auto-configured");
> >
> > -    if (!kvm_eventfds_enabled()) {
> > +    if (kvm_enabled() && !kvm_eventfds_enabled()) {
> >           dev->flags &= ~VIRTIO_CCW_FLAG_USE_IOEVENTFD;
> >       }
> >
> > diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
> > index 9faca04b52..bdb9bdbc9d 100644
> > --- a/target/s390x/cpu.h
> > +++ b/target/s390x/cpu.h
> > @@ -1264,7 +1264,11 @@ static inline int 
> > s390_assign_subch_ioeventfd(EventNotifier *notifier,
> >                                                 uint32_t sch_id, int vq,
> >                                                 bool assign)
> >   {
> > -    return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
> > +    if (kvm_enabled()) {
> > +        return kvm_s390_assign_subch_ioeventfd(notifier, sch_id, vq, assign);
> > +    } else {
> > +        return 0;
> > +    }
> >   }
> >
> >   static inline void s390_crypto_reset(void)

--
Regards
QingFeng Hao