On Wed, 30 Mar 2022 11:50:49 +0800, Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
> 在 2022/3/24 下午4:28, Xuan Zhuo 写道:
> > 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.
>
>
> So I think let's just stick to the current style by passing individual
> parameters, and we can refactor it on top of this series.
>
> This will let us to focus on the core logic.
I am implementing the function of reusing the buffer mentioned by Michael, and
at this time there will be a lot of dependence on this structure. Because I
want to save some information(desc, desc_extra, desc_stete), these structures
are very useful at this time.
The only problem is that this patch set is too big. ^_^
Thanks.
>
> Thanks
>
>
> >
> > 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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