On Tue, 22 Mar 2022 14:38:12 +0800, Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
> 在 2022/3/14 下午5:34, Xuan Zhuo 写道:
> > Separate the logic of packed to create vring queue.
> >
> > For the convenience of passing parameters, add a structure
> > vring_packed.
> >
> > This feature is required for subsequent virtuqueue reset vring.
> >
> > Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
> > ---
> > drivers/virtio/virtio_ring.c | 121 ++++++++++++++++++++++++++---------
> > 1 file changed, 92 insertions(+), 29 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> > index a15869514146..96ff2dabda14 100644
> > --- a/drivers/virtio/virtio_ring.c
> > +++ b/drivers/virtio/virtio_ring.c
> > @@ -85,6 +85,18 @@ struct vring_desc_extra {
> > u16 next; /* The next desc state in a list. */
> > };
> >
> > +struct vring_packed {
> > + u32 num;
> > + struct vring_packed_desc *ring;
> > + struct vring_packed_desc_event *driver;
> > + struct vring_packed_desc_event *device;
> > + dma_addr_t ring_dma_addr;
> > + dma_addr_t driver_event_dma_addr;
> > + dma_addr_t device_event_dma_addr;
> > + size_t ring_size_in_bytes;
> > + size_t event_size_in_bytes;
> > +};
> > +
>
>
> Interesting, a nitpick here is that if it is only used by one helper,
> it's probably not worth to bother.
Indeed only one helper will use it. Because vring_alloc_queue_packed will pass
too many variables. If we use function parameters, I think this function is too
ugly.
>
> And if we want to do that, we need
>
> 1) use a separated patch
If we split this patch again, we can only separate vring_free_vring_packed()
out.
>
> 2) do it for split virtqueue as well
Earlier versions, I did create a struct for split too, but you replied that it
wasn't worth it, so I removed the separate struct used by split.
Thanks.
>
> Thanks
>
>
> > struct vring_virtqueue {
> > struct virtqueue vq;
> >
> > @@ -1735,45 +1747,101 @@ static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num)
> > return desc_extra;
> > }
> >
> > -static struct virtqueue *vring_create_virtqueue_packed(
> > - 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 void vring_free_vring_packed(struct vring_packed *vring,
> > + struct virtio_device *vdev)
> > +{
> > + dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
> > + struct vring_packed_desc_event *driver, *device;
> > + size_t ring_size_in_bytes, event_size_in_bytes;
> > + struct vring_packed_desc *ring;
> > +
> > + ring = vring->ring;
> > + driver = vring->driver;
> > + device = vring->device;
> > + ring_size_in_bytes = vring->ring_size_in_bytes;
> > + event_size_in_bytes = vring->event_size_in_bytes;
> > + ring_dma_addr = vring->ring_dma_addr;
> > + driver_event_dma_addr = vring->driver_event_dma_addr;
> > + device_event_dma_addr = vring->device_event_dma_addr;
> > +
> > + if (device)
> > + vring_free_queue(vdev, event_size_in_bytes, device, device_event_dma_addr);
> > +
> > + if (driver)
> > + vring_free_queue(vdev, event_size_in_bytes, driver, driver_event_dma_addr);
> > +
> > + if (ring)
> > + vring_free_queue(vdev, ring_size_in_bytes, ring, ring_dma_addr);
> > +}
> > +
> > +static int vring_alloc_queue_packed(struct vring_packed *vring,
> > + struct virtio_device *vdev,
> > + u32 num)
> > {
> > - struct vring_virtqueue *vq;
> > struct vring_packed_desc *ring;
> > struct vring_packed_desc_event *driver, *device;
> > dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
> > size_t ring_size_in_bytes, event_size_in_bytes;
> >
> > + memset(vring, 0, sizeof(*vring));
> > +
> > ring_size_in_bytes = num * sizeof(struct vring_packed_desc);
> >
> > ring = vring_alloc_queue(vdev, ring_size_in_bytes,
> > &ring_dma_addr,
> > GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
> > if (!ring)
> > - goto err_ring;
> > + goto err;
> > +
> > + vring->num = num;
> > + vring->ring = ring;
> > + vring->ring_size_in_bytes = ring_size_in_bytes;
> > + vring->ring_dma_addr = ring_dma_addr;
> >
> > event_size_in_bytes = sizeof(struct vring_packed_desc_event);
> > + vring->event_size_in_bytes = event_size_in_bytes;
> >
> > driver = vring_alloc_queue(vdev, event_size_in_bytes,
> > &driver_event_dma_addr,
> > GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
> > if (!driver)
> > - goto err_driver;
> > + goto err;
> > +
> > + vring->driver = driver;
> > + vring->driver_event_dma_addr = driver_event_dma_addr;
> >
> > device = vring_alloc_queue(vdev, event_size_in_bytes,
> > &device_event_dma_addr,
> > GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
> > if (!device)
> > - goto err_device;
> > + goto err;
> > +
> > + vring->device = device;
> > + vring->device_event_dma_addr = device_event_dma_addr;
> > + return 0;
> > +
> > +err:
> > + vring_free_vring_packed(vring, vdev);
> > + return -ENOMEM;
> > +}
> > +
> > +static struct virtqueue *vring_create_virtqueue_packed(
> > + 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 *vq;
> > + struct vring_packed vring;
> > +
> > + if (vring_alloc_queue_packed(&vring, vdev, num))
> > + goto err_vq;
> >
> > vq = kmalloc(sizeof(*vq), GFP_KERNEL);
> > if (!vq)
> > @@ -1805,17 +1873,17 @@ static struct virtqueue *vring_create_virtqueue_packed(
> > if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
> > vq->weak_barriers = false;
> >
> > - vq->packed.ring_dma_addr = ring_dma_addr;
> > - vq->packed.driver_event_dma_addr = driver_event_dma_addr;
> > - vq->packed.device_event_dma_addr = device_event_dma_addr;
> > + vq->packed.ring_dma_addr = vring.ring_dma_addr;
> > + vq->packed.driver_event_dma_addr = vring.driver_event_dma_addr;
> > + vq->packed.device_event_dma_addr = vring.device_event_dma_addr;
> >
> > - vq->packed.ring_size_in_bytes = ring_size_in_bytes;
> > - vq->packed.event_size_in_bytes = event_size_in_bytes;
> > + vq->packed.ring_size_in_bytes = vring.ring_size_in_bytes;
> > + vq->packed.event_size_in_bytes = vring.event_size_in_bytes;
> >
> > vq->packed.vring.num = num;
> > - vq->packed.vring.desc = ring;
> > - vq->packed.vring.driver = driver;
> > - vq->packed.vring.device = device;
> > + vq->packed.vring.desc = vring.ring;
> > + vq->packed.vring.driver = vring.driver;
> > + vq->packed.vring.device = vring.device;
> >
> > vq->packed.next_avail_idx = 0;
> > vq->packed.avail_wrap_counter = 1;
> > @@ -1856,12 +1924,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
> > err_desc_state:
> > kfree(vq);
> > err_vq:
> > - vring_free_queue(vdev, event_size_in_bytes, device, device_event_dma_addr);
> > -err_device:
> > - vring_free_queue(vdev, event_size_in_bytes, driver, driver_event_dma_addr);
> > -err_driver:
> > - vring_free_queue(vdev, ring_size_in_bytes, ring, ring_dma_addr);
> > -err_ring:
> > + vring_free_vring_packed(&vring, vdev);
> > return NULL;
> > }
> >
>
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