[PATCH v11 05/40] virtio_ring: split vring_virtqueue

[Jason Wang]

On Wed, Jun 29, 2022 at 2:57 PM Xuan Zhuo <xuanzhuo at linux.alibaba.com> wrote:
>
> Separate the two inline structures(split and packed) from the structure
> vring_virtqueue.
>
> In this way, we can use these two structures later to pass parameters
> and retain temporary variables.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>

Acked-by: Jason Wang <jasowang at redhat.com>

> ---
>  drivers/virtio/virtio_ring.c | 116 ++++++++++++++++++-----------------
>  1 file changed, 60 insertions(+), 56 deletions(-)
>
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index bb4e8ae09c9b..2806e033a651 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -85,6 +85,64 @@ struct vring_desc_extra {
>         u16 next;                       /* The next desc state in a list. */
>  };
>
> +struct vring_virtqueue_split {
> +       /* Actual memory layout for this queue. */
> +       struct vring vring;
> +
> +       /* Last written value to avail->flags */
> +       u16 avail_flags_shadow;
> +
> +       /*
> +        * Last written value to avail->idx in
> +        * guest byte order.
> +        */
> +       u16 avail_idx_shadow;
> +
> +       /* Per-descriptor state. */
> +       struct vring_desc_state_split *desc_state;
> +       struct vring_desc_extra *desc_extra;
> +
> +       /* DMA address and size information */
> +       dma_addr_t queue_dma_addr;
> +       size_t queue_size_in_bytes;
> +};
> +
> +struct vring_virtqueue_packed {
> +       /* Actual memory layout for this queue. */
> +       struct {
> +               unsigned int num;
> +               struct vring_packed_desc *desc;
> +               struct vring_packed_desc_event *driver;
> +               struct vring_packed_desc_event *device;
> +       } vring;
> +
> +       /* Driver ring wrap counter. */
> +       bool avail_wrap_counter;
> +
> +       /* Avail used flags. */
> +       u16 avail_used_flags;
> +
> +       /* Index of the next avail descriptor. */
> +       u16 next_avail_idx;
> +
> +       /*
> +        * Last written value to driver->flags in
> +        * guest byte order.
> +        */
> +       u16 event_flags_shadow;
> +
> +       /* Per-descriptor state. */
> +       struct vring_desc_state_packed *desc_state;
> +       struct vring_desc_extra *desc_extra;
> +
> +       /* DMA address and size information */
> +       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;
> +};
> +
>  struct vring_virtqueue {
>         struct virtqueue vq;
>
> @@ -124,64 +182,10 @@ struct vring_virtqueue {
>
>         union {
>                 /* Available for split ring */
> -               struct {
> -                       /* Actual memory layout for this queue. */
> -                       struct vring vring;
> -
> -                       /* Last written value to avail->flags */
> -                       u16 avail_flags_shadow;
> -
> -                       /*
> -                        * Last written value to avail->idx in
> -                        * guest byte order.
> -                        */
> -                       u16 avail_idx_shadow;
> -
> -                       /* Per-descriptor state. */
> -                       struct vring_desc_state_split *desc_state;
> -                       struct vring_desc_extra *desc_extra;
> -
> -                       /* DMA address and size information */
> -                       dma_addr_t queue_dma_addr;
> -                       size_t queue_size_in_bytes;
> -               } split;
> +               struct vring_virtqueue_split split;
>
>                 /* Available for packed ring */
> -               struct {
> -                       /* Actual memory layout for this queue. */
> -                       struct {
> -                               unsigned int num;
> -                               struct vring_packed_desc *desc;
> -                               struct vring_packed_desc_event *driver;
> -                               struct vring_packed_desc_event *device;
> -                       } vring;
> -
> -                       /* Driver ring wrap counter. */
> -                       bool avail_wrap_counter;
> -
> -                       /* Avail used flags. */
> -                       u16 avail_used_flags;
> -
> -                       /* Index of the next avail descriptor. */
> -                       u16 next_avail_idx;
> -
> -                       /*
> -                        * Last written value to driver->flags in
> -                        * guest byte order.
> -                        */
> -                       u16 event_flags_shadow;
> -
> -                       /* Per-descriptor state. */
> -                       struct vring_desc_state_packed *desc_state;
> -                       struct vring_desc_extra *desc_extra;
> -
> -                       /* DMA address and size information */
> -                       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;
> -               } packed;
> +               struct vring_virtqueue_packed packed;
>         };
>
>         /* How to notify other side. FIXME: commonalize hcalls! */
> --
> 2.31.0
>