Commit af8ececd authored by Viktor Prutyanov's avatar Viktor Prutyanov Committed by Michael S. Tsirkin
Browse files

virtio: add VIRTIO_F_NOTIFICATION_DATA feature support 



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, channel I/O and modern PCI
transports.

Signed-off-by: default avatarViktor Prutyanov <viktor@daynix.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
Reviewed-by: default avatarXuan Zhuo <xuanzhuo@linux.alibaba.com>
Message-Id: <20230413081855.36643-2-alvaro.karsz@solid-run.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 3616bf37

drivers/s390/virtio/virtio_ccw.c

+19 −3
Original line number Diff line number Diff line
@@ -391,7 +391,7 @@ static void virtio_ccw_drop_indicator(struct virtio_ccw_device *vcdev, 
	ccw_device_dma_free(vcdev->cdev, thinint_area, sizeof(*thinint_area));

}



static bool virtio_ccw_kvm_notify(struct virtqueue *vq)

static inline bool virtio_ccw_do_kvm_notify(struct virtqueue *vq, u32 data)

{

	struct virtio_ccw_vq_info *info = vq->priv;

	struct virtio_ccw_device *vcdev;
@@ -402,12 +402,22 @@ static bool virtio_ccw_kvm_notify(struct virtqueue *vq) 
	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;

}



static bool virtio_ccw_kvm_notify(struct virtqueue *vq)

{

	return virtio_ccw_do_kvm_notify(vq, vq->index);

}



static bool virtio_ccw_kvm_notify_with_data(struct virtqueue *vq)

{

	return virtio_ccw_do_kvm_notify(vq, vring_notification_data(vq));

}



static int virtio_ccw_read_vq_conf(struct virtio_ccw_device *vcdev,

				   struct ccw1 *ccw, int index)

{
@@ -495,6 +505,7 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev, 
					     struct ccw1 *ccw)

{

	struct virtio_ccw_device *vcdev = to_vc_device(vdev);

	bool (*notify)(struct virtqueue *vq);

	int err;

	struct virtqueue *vq = NULL;

	struct virtio_ccw_vq_info *info;
@@ -502,6 +513,11 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev, 
	unsigned long flags;

	bool may_reduce;



	if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA))

		notify = virtio_ccw_kvm_notify_with_data;

	else

		notify = virtio_ccw_kvm_notify;



	/* Allocate queue. */

	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);

	if (!info) {
@@ -524,7 +540,7 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev, 
	may_reduce = vcdev->revision > 0;

	vq = vring_create_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN,

				    vdev, true, may_reduce, ctx,

				    virtio_ccw_kvm_notify, callback, name);

				    notify, callback, name);



	if (!vq) {

		/* For now, we fail if we can't get the requested size. */

drivers/virtio/virtio_mmio.c

+17 −1
Original line number Diff line number Diff line
@@ -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);



	return true;

}



/* Notify all virtqueues on an interrupt. */

static irqreturn_t vm_interrupt(int irq, void *opaque)

{
@@ -363,12 +373,18 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in 
				  const char *name, bool ctx)

{

	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);

	bool (*notify)(struct virtqueue *vq);

	struct virtio_mmio_vq_info *info;

	struct virtqueue *vq;

	unsigned long flags;

	unsigned int num;

	int err;



	if (__virtio_test_bit(vdev, VIRTIO_F_NOTIFICATION_DATA))

		notify = vm_notify_with_data;

	else

		notify = vm_notify;



	if (!name)

		return NULL;
@@ -397,7 +413,7 @@ 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;

drivers/virtio/virtio_pci_modern.c

+16 −1
Original line number Diff line number Diff line
@@ -288,6 +288,15 @@ static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector) 
	return vp_modern_config_vector(&vp_dev->mdev, vector);

}



static bool vp_notify_with_data(struct virtqueue *vq)

{

	u32 data = vring_notification_data(vq);



	iowrite32(data, (void __iomem *)vq->priv);



	return true;

}



static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,

				  struct virtio_pci_vq_info *info,

				  unsigned int index,
@@ -298,10 +307,16 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, 
{



	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;

	bool (*notify)(struct virtqueue *vq);

	struct virtqueue *vq;

	u16 num;

	int err;



	if (__virtio_test_bit(&vp_dev->vdev, VIRTIO_F_NOTIFICATION_DATA))

		notify = vp_notify_with_data;

	else

		notify = vp_notify;



	if (index >= vp_modern_get_num_queues(mdev))

		return ERR_PTR(-EINVAL);
@@ -316,7 +331,7 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev, 
	vq = vring_create_virtqueue(index, num,

				    SMP_CACHE_BYTES, &vp_dev->vdev,

				    true, true, ctx,

				    vp_notify, callback, name);

				    notify, callback, name);

	if (!vq)

		return ERR_PTR(-ENOMEM);

drivers/virtio/virtio_ring.c

+19 −0
Original line number Diff line number Diff line
@@ -2762,6 +2762,23 @@ void vring_del_virtqueue(struct virtqueue *_vq) 
}

EXPORT_SYMBOL_GPL(vring_del_virtqueue);



u32 vring_notification_data(struct virtqueue *_vq)

{

	struct vring_virtqueue *vq = to_vvq(_vq);

	u16 next;



	if (vq->packed_ring)

		next = (vq->packed.next_avail_idx &

				~(-(1 << VRING_PACKED_EVENT_F_WRAP_CTR))) |

			vq->packed.avail_wrap_counter <<

				VRING_PACKED_EVENT_F_WRAP_CTR;

	else

		next = vq->split.avail_idx_shadow;



	return next << 16 | _vq->index;

}

EXPORT_SYMBOL_GPL(vring_notification_data);



/* Manipulates transport-specific feature bits. */

void vring_transport_features(struct virtio_device *vdev)

{
@@ -2781,6 +2798,8 @@ void vring_transport_features(struct virtio_device *vdev) 
			break;

		case VIRTIO_F_ORDER_PLATFORM:

			break;

		case VIRTIO_F_NOTIFICATION_DATA:

			break;

		default:

			/* We don't understand this bit. */

			__virtio_clear_bit(vdev, i);

include/linux/virtio_ring.h

+2 −0
Original line number Diff line number Diff line
@@ -117,4 +117,6 @@ void vring_del_virtqueue(struct virtqueue *vq); 
void vring_transport_features(struct virtio_device *vdev);



irqreturn_t vring_interrupt(int irq, void *_vq);



u32 vring_notification_data(struct virtqueue *_vq);

#endif /* _LINUX_VIRTIO_RING_H */