On Tue, 4 Jul 2017 10:32:31 +0200
QingFeng Hao <ha...@linux.vnet.ibm.com> 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.
It might be good to add a sentence that we don't have an equivalent to
"memory: emulate ioeventfd" for ccw yet, but that this doesn't hurt.
>
> 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 <ha...@linux.vnet.ibm.com>
> ---
> 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)
Reviewed-by: Cornelia Huck <coh...@redhat.com>
