Xuan Zhuo
2022-Jul-20 03:04 UTC
[PATCH v12 08/40] virtio_ring: split: extract the logic of alloc queue
Separate the logic of split to create vring queue.
This feature is required for subsequent virtuqueue reset vring.
Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 68 ++++++++++++++++++++++--------------
1 file changed, 42 insertions(+), 26 deletions(-)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index c94c5461e702..c7971438bb2c 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -950,28 +950,19 @@ static void vring_free_split(struct vring_virtqueue_split
*vring_split,
kfree(vring_split->desc_extra);
}
-static struct virtqueue *vring_create_virtqueue_split(
- unsigned int index,
- unsigned int num,
- unsigned int vring_align,
- struct virtio_device *vdev,
- bool weak_barriers,
- bool may_reduce_num,
- bool context,
- bool (*notify)(struct virtqueue *),
- void (*callback)(struct virtqueue *),
- const char *name)
+static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split,
+ struct virtio_device *vdev,
+ u32 num,
+ unsigned int vring_align,
+ bool may_reduce_num)
{
- struct virtqueue *vq;
void *queue = NULL;
dma_addr_t dma_addr;
- size_t queue_size_in_bytes;
- struct vring vring;
/* We assume num is a power of 2. */
if (num & (num - 1)) {
dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num);
- return NULL;
+ return -EINVAL;
}
/* TODO: allocate each queue chunk individually */
@@ -982,11 +973,11 @@ static struct virtqueue *vring_create_virtqueue_split(
if (queue)
break;
if (!may_reduce_num)
- return NULL;
+ return -ENOMEM;
}
if (!num)
- return NULL;
+ return -ENOMEM;
if (!queue) {
/* Try to get a single page. You are my only hope! */
@@ -994,21 +985,46 @@ static struct virtqueue *vring_create_virtqueue_split(
&dma_addr, GFP_KERNEL|__GFP_ZERO);
}
if (!queue)
- return NULL;
+ return -ENOMEM;
+
+ vring_init(&vring_split->vring, num, queue, vring_align);
- queue_size_in_bytes = vring_size(num, vring_align);
- vring_init(&vring, num, queue, vring_align);
+ vring_split->queue_dma_addr = dma_addr;
+ vring_split->queue_size_in_bytes = vring_size(num, vring_align);
+
+ return 0;
+}
+
+static struct virtqueue *vring_create_virtqueue_split(
+ unsigned int index,
+ unsigned int num,
+ unsigned int vring_align,
+ struct virtio_device *vdev,
+ bool weak_barriers,
+ bool may_reduce_num,
+ bool context,
+ bool (*notify)(struct virtqueue *),
+ void (*callback)(struct virtqueue *),
+ const char *name)
+{
+ struct vring_virtqueue_split vring_split = {};
+ struct virtqueue *vq;
+ int err;
+
+ err = vring_alloc_queue_split(&vring_split, vdev, num, vring_align,
+ may_reduce_num);
+ if (err)
+ return NULL;
- vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
- notify, callback, name);
+ vq = __vring_new_virtqueue(index, vring_split.vring, vdev, weak_barriers,
+ context, notify, callback, name);
if (!vq) {
- vring_free_queue(vdev, queue_size_in_bytes, queue,
- dma_addr);
+ vring_free_split(&vring_split, vdev);
return NULL;
}
- to_vvq(vq)->split.queue_dma_addr = dma_addr;
- to_vvq(vq)->split.queue_size_in_bytes = queue_size_in_bytes;
+ to_vvq(vq)->split.queue_dma_addr = vring_split.queue_dma_addr;
+ to_vvq(vq)->split.queue_size_in_bytes = vring_split.queue_size_in_bytes;
to_vvq(vq)->we_own_ring = true;
return vq;
--
2.31.0
Jason Wang
2022-Jul-21 09:13 UTC
[PATCH v12 08/40] virtio_ring: split: extract the logic of alloc queue
? 2022/7/20 11:04, Xuan Zhuo ??:> Separate the logic of split to create vring queue. > > This feature is required for subsequent virtuqueue reset vring. > > Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> > --- > drivers/virtio/virtio_ring.c | 68 ++++++++++++++++++++++-------------- > 1 file changed, 42 insertions(+), 26 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index c94c5461e702..c7971438bb2c 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -950,28 +950,19 @@ static void vring_free_split(struct vring_virtqueue_split *vring_split, > kfree(vring_split->desc_extra); > } > > -static struct virtqueue *vring_create_virtqueue_split( > - unsigned int index, > - unsigned int num, > - unsigned int vring_align, > - struct virtio_device *vdev, > - bool weak_barriers, > - bool may_reduce_num, > - bool context, > - bool (*notify)(struct virtqueue *), > - void (*callback)(struct virtqueue *), > - const char *name) > +static int vring_alloc_queue_split(struct vring_virtqueue_split *vring_split, > + struct virtio_device *vdev, > + u32 num, > + unsigned int vring_align, > + bool may_reduce_num) > { > - struct virtqueue *vq; > void *queue = NULL; > dma_addr_t dma_addr; > - size_t queue_size_in_bytes; > - struct vring vring; > > /* We assume num is a power of 2. */ > if (num & (num - 1)) { > dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num); > - return NULL; > + return -EINVAL; > } > > /* TODO: allocate each queue chunk individually */ > @@ -982,11 +973,11 @@ static struct virtqueue *vring_create_virtqueue_split( > if (queue) > break; > if (!may_reduce_num) > - return NULL; > + return -ENOMEM; > } > > if (!num) > - return NULL; > + return -ENOMEM; > > if (!queue) { > /* Try to get a single page. You are my only hope! */ > @@ -994,21 +985,46 @@ static struct virtqueue *vring_create_virtqueue_split( > &dma_addr, GFP_KERNEL|__GFP_ZERO); > } > if (!queue) > - return NULL; > + return -ENOMEM; > + > + vring_init(&vring_split->vring, num, queue, vring_align); > > - queue_size_in_bytes = vring_size(num, vring_align); > - vring_init(&vring, num, queue, vring_align); > + vring_split->queue_dma_addr = dma_addr; > + vring_split->queue_size_in_bytes = vring_size(num, vring_align); > + > + return 0; > +} > + > +static struct virtqueue *vring_create_virtqueue_split( > + unsigned int index, > + unsigned int num, > + unsigned int vring_align, > + struct virtio_device *vdev, > + bool weak_barriers, > + bool may_reduce_num, > + bool context, > + bool (*notify)(struct virtqueue *), > + void (*callback)(struct virtqueue *), > + const char *name) > +{ > + struct vring_virtqueue_split vring_split = {}; > + struct virtqueue *vq; > + int err; > + > + err = vring_alloc_queue_split(&vring_split, vdev, num, vring_align, > + may_reduce_num); > + if (err) > + return NULL; > > - vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context, > - notify, callback, name); > + vq = __vring_new_virtqueue(index, vring_split.vring, vdev, weak_barriers, > + context, notify, callback, name); > if (!vq) { > - vring_free_queue(vdev, queue_size_in_bytes, queue, > - dma_addr); > + vring_free_split(&vring_split, vdev); > return NULL; > } > > - to_vvq(vq)->split.queue_dma_addr = dma_addr; > - to_vvq(vq)->split.queue_size_in_bytes = queue_size_in_bytes; > + to_vvq(vq)->split.queue_dma_addr = vring_split.queue_dma_addr; > + to_vvq(vq)->split.queue_size_in_bytes = vring_split.queue_size_in_bytes;This still seems a little bit redundant since the current logic is a little bit complicated since the vq->split is not initialized in a single place. I wonder if it's better to: vring_alloc_queue_split() vring_alloc_desc_extra() (reorder to make patch 9 come first) then we can simply assign vring_split to vq->split in __vring_new_virtqueue() since it has: ??? vq->split.queue_dma_addr = 0; ?? ?vq->split.queue_size_in_bytes = 0; ??? vq->split.vring = vring; ??? vq->split.avail_flags_shadow = 0; ??? vq->split.avail_idx_shadow = 0; This seems to simplify the logic and task of e.g virtqueue_vring_attach_split() to a simple: vq->split= vring_split; And if this makes sense, we can do something similar to packed ring. Thanks> to_vvq(vq)->we_own_ring = true; > > return vq;