Cornelia Huck
2023-Mar-21 14:59 UTC
[PATCH v3] virtio: add VIRTIO_F_NOTIFICATION_DATA feature support
On Tue, Mar 21 2023, Viktor Prutyanov <viktor at daynix.com> wrote:> According to VirtIO spec v1.2, VIRTIO_F_NOTIFICATION_DATA feature > indicates that the driver passes extra data along with the queue > notifications. > > In a split queue case, the extra data is 16-bit available index. In a > packed queue case, the extra data is 1-bit wrap counter and 15-bit > available index. > > Add support for this feature for MMIO, PCI and channel I/O transports. > > Signed-off-by: Viktor Prutyanov <viktor at daynix.com> > --- > v3: support feature in virtio_ccw, remove VM_NOTIFY, use avail_idx_shadow, > remove byte swap, rename to vring_notification_data > v2: reject the feature in virtio_ccw, replace __le32 with u32 > > drivers/s390/virtio/virtio_ccw.c | 4 +++- > drivers/virtio/virtio_mmio.c | 14 +++++++++++++- > drivers/virtio/virtio_pci_common.c | 10 ++++++++++ > drivers/virtio/virtio_pci_common.h | 4 ++++ > drivers/virtio/virtio_pci_legacy.c | 2 +- > drivers/virtio/virtio_pci_modern.c | 2 +- > drivers/virtio/virtio_ring.c | 17 +++++++++++++++++ > include/linux/virtio_ring.h | 2 ++ > include/uapi/linux/virtio_config.h | 6 ++++++ > 9 files changed, 57 insertions(+), 4 deletions(-) > > diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c > index 954fc31b4bc7..c33172c5b8d5 100644 > --- a/drivers/s390/virtio/virtio_ccw.c > +++ b/drivers/s390/virtio/virtio_ccw.c > @@ -396,13 +396,15 @@ static bool virtio_ccw_kvm_notify(struct virtqueue *vq) > struct virtio_ccw_vq_info *info = vq->priv; > struct virtio_ccw_device *vcdev; > struct subchannel_id schid; > + u32 data = __virtio_test_bit(vq->vdev, VIRTIO_F_NOTIFICATION_DATA) ? > + vring_notification_data(vq) : vq->index; > > vcdev = to_vc_device(info->vq->vdev); > ccw_device_get_schid(vcdev->cdev, &schid); > BUILD_BUG_ON(sizeof(struct subchannel_id) != sizeof(unsigned int)); > info->cookie = kvm_hypercall3(KVM_S390_VIRTIO_CCW_NOTIFY, > *((unsigned int *)&schid), > - vq->index, info->cookie); > + data, info->cookie); > if (info->cookie < 0) > return false; > return true; > diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c > index 3ff746e3f24a..7c16e622c33d 100644 > --- a/drivers/virtio/virtio_mmio.c > +++ b/drivers/virtio/virtio_mmio.c > @@ -285,6 +285,16 @@ static bool vm_notify(struct virtqueue *vq) > return true; > } > > +static bool vm_notify_with_data(struct virtqueue *vq) > +{ > + struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev); > + u32 data = vring_notification_data(vq); > + > + writel(data, vm_dev->base + VIRTIO_MMIO_QUEUE_NOTIFY);Can't you simply use the same method as for ccw, i.e. use one callback function that simply writes one value or the other?> + > + return true; > +} > + > /* Notify all virtqueues on an interrupt. */ > static irqreturn_t vm_interrupt(int irq, void *opaque) > { > @@ -368,6 +378,8 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in > unsigned long flags; > unsigned int num; > int err; > + bool (*notify)(struct virtqueue *vq) = __virtio_test_bit(vdev, > + VIRTIO_F_NOTIFICATION_DATA) ? vm_notify_with_data : vm_notify; > > if (!name) > return NULL; > @@ -397,7 +409,7 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in > > /* Create the vring */ > vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, vdev, > - true, true, ctx, vm_notify, callback, name); > + true, true, ctx, notify, callback, name); > if (!vq) { > err = -ENOMEM; > goto error_new_virtqueue; > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c > index a6c86f916dbd..e915c22f2384 100644 > --- a/drivers/virtio/virtio_pci_common.c > +++ b/drivers/virtio/virtio_pci_common.c > @@ -43,6 +43,16 @@ bool vp_notify(struct virtqueue *vq) > /* we write the queue's selector into the notification register to > * signal the other end */ > iowrite16(vq->index, (void __iomem *)vq->priv); > + > + return true; > +} > + > +bool vp_notify_with_data(struct virtqueue *vq) > +{ > + u32 data = vring_notification_data(vq); > + > + iowrite32(data, (void __iomem *)vq->priv);Same for pci.> + > return true; > } >