On Wed, Sep 11, 2013 at 05:46:39PM +0300, Michael S. Tsirkin wrote:
> diff --git a/virtio-v1.0-wd01-part1-specification.txt b/virtio-v1.0-wd01-part1-specification.txt
> index fcd9fd7..9a40973 100644
> --- a/virtio-v1.0-wd01-part1-specification.txt
> +++ b/virtio-v1.0-wd01-part1-specification.txt
> @@ -223,6 +223,45 @@ transmit and one for receive. Each queue has a 16-bit queue size
> parameter, which sets the number of entries and implies the total size
> of the queue.
>
> +Each virtqueue consists of three parts:
> +
> + Descriptor Table
> + Available Ring
> + Used Ring
> +
> +where each part is physically-contiguous in guest memory,
> +and has different alignment requirements.
> +
> +The Queue Size field controls the total number of bytes
> +required for each part of the virtqueue.
I'm lost here because I don't know where the Queue Size field comes
from. I think the table needs to be shown first, then the explanation
can be given:
...table...
The Size column gives the total number of bytes required for each part
of the virtqueue.
> +
> +The memory aligment and size requirements, in bytes, of each part of the
> +virtqueue are summarized in the following table (qsz is the Queue Size field):
Perhaps it's clearer to say:
qsz is the maximum number of buffers. For example, if qsz is 4 then at
most 4 buffers can be transferred at any given time.
> @@ -814,9 +852,11 @@ This is done as follows, for each virtqueue a device has:
> always a power of 2. This controls how big the virtqueue is
> (see "2.1.4. Virtqueues"). If this field is 0, the virtqueue does not exist.
>
> -3. Allocate and zero virtqueue in contiguous physical memory, on
> - a 4096 byte alignment. Write the physical address, divided by
> - 4096 to the Queue Address field.[6]
> +3. Optionally, select a smaller virtqueue size and write it in the Queue Size
> + field.
3...
> +3. Allocate and zero Descriptor Table, Available and Used rings for the
> + virtqueue in contiguous physical memory.
...and 3. Should this list be renumbered?
