[PATCH 01/10] virtio/s390: use vring_create_virtqueue

Halil Pasic
2019-04-26T18:32:36Z

The commit 2a2d1382fe9d ("virtio: Add improved queue allocation API")
establishes a new way of allocating virtqueues (as a part of the effort
that taught DMA to virtio rings).

In the future we will want virtio-ccw to use the DMA API as well.

Let us switch from the legacy method of allocating virtqueues to
vring_create_virtqueue() as the first step into that direction.

Signed-off-by: Halil Pasic <pasic@linux.ibm.com>
---
drivers/s390/virtio/virtio_ccw.c | 30 +++++++++++-------------------
1 file changed, 11 insertions(+), 19 deletions(-)

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index 74c328321889..2c66941ef3d0 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -108,7 +108,6 @@ struct virtio_rev_info {
struct virtio_ccw_vq_info {
struct virtqueue *vq;
int num;
- void *queue;
union {
struct vq_info_block s;
struct vq_info_block_legacy l;
@@ -423,7 +422,6 @@ static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
struct virtio_ccw_device *vcdev = to_vc_device(vq->vdev);
struct virtio_ccw_vq_info *info = vq->priv;
unsigned long flags;
- unsigned long size;
int ret;
unsigned int index = vq->index;

@@ -461,8 +459,6 @@ static void virtio_ccw_del_vq(struct virtqueue *vq, struct ccw1 *ccw)
ret, index);

vring_del_virtqueue(vq);
- size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
- free_pages_exact(info->queue, size);
kfree(info->info_block);
kfree(info);
}
@@ -494,8 +490,9 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
int err;
struct virtqueue *vq = NULL;
struct virtio_ccw_vq_info *info;
- unsigned long size = 0; /* silence the compiler */
+ u64 queue;
unsigned long flags;
+ bool may_reduce;

/* Allocate queue. */
info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
@@ -516,33 +513,30 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
err = info->num;
goto out_err;
}
- size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
- info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
- if (info->queue == NULL) {
- dev_warn(&vcdev->cdev->dev, "no queue\n");
- err = -ENOMEM;
- goto out_err;
- }
+ 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);

- vq = vring_new_virtqueue(i, info->num, KVM_VIRTIO_CCW_RING_ALIGN, vdev,
- true, ctx, info->queue, virtio_ccw_kvm_notify,
- callback, name);
if (!vq) {
/* For now, we fail if we can't get the requested size. */
dev_warn(&vcdev->cdev->dev, "no vq\n");
err = -ENOMEM;
goto out_err;
}
+ /* it may have been reduced */
+ info->num = virtqueue_get_vring_size(vq);

/* Register it with the host. */
+ queue = virtqueue_get_desc_addr(vq);
if (vcdev->revision == 0) {
- info->info_block->l.queue = (__u64)info->queue;
+ info->info_block->l.queue = queue;
info->info_block->l.align = KVM_VIRTIO_CCW_RING_ALIGN;
info->info_block->l.index = i;
info->info_block->l.num = info->num;
ccw->count = sizeof(info->info_block->l);
} else {
- info->info_block->s.desc = (__u64)info->queue;
+ info->info_block->s.desc = queue;
info->info_block->s.index = i;
info->info_block->s.num = info->num;
info->info_block->s.avail = (__u64)virtqueue_get_avail(vq);
@@ -572,8 +566,6 @@ static struct virtqueue *virtio_ccw_setup_vq(struct virtio_device *vdev,
if (vq)
vring_del_virtqueue(vq);
if (info) {
- if (info->queue)
- free_pages_exact(info->queue, size);
kfree(info->info_block);
}
kfree(info);
--
2.16.4