Re: [PATCH next 4/7] vmxnet3: add command to set ring buffer sizes

[Ferruh Yigit <ferruh.yigit@amd.com>]

On 4/12/2023 5:26 PM, Ronak Doshi wrote:
> This patch adds a new command to set ring buffer sizes. This is
> required to pass the buffer size information to passthrough devices.
> Also, ring sizes are round down to power of 2.
> 
> Signed-off-by: Ronak Doshi <doshir@vmware.com>
> Acked-by: Jochen Behrens <jbehrens@vmware.com>
> ---
>  drivers/net/vmxnet3/base/vmxnet3_defs.h | 15 +++++++++++++++
>  drivers/net/vmxnet3/vmxnet3_ethdev.c    | 18 ++++++++++++++++++
>  drivers/net/vmxnet3/vmxnet3_ethdev.h    |  1 +
>  drivers/net/vmxnet3/vmxnet3_rxtx.c      |  7 +++++++
>  4 files changed, 41 insertions(+)
> 
> diff --git a/drivers/net/vmxnet3/base/vmxnet3_defs.h b/drivers/net/vmxnet3/base/vmxnet3_defs.h
> index 27f35a0062..d8cc295b08 100644
> --- a/drivers/net/vmxnet3/base/vmxnet3_defs.h
> +++ b/drivers/net/vmxnet3/base/vmxnet3_defs.h
> @@ -105,6 +105,9 @@ typedef enum {
>     VMXNET3_CMD_RESERVED4,
>     VMXNET3_CMD_REGISTER_MEMREGS,
>     VMXNET3_CMD_SET_RSS_FIELDS,
> +   VMXNET3_CMD_RESERVED9,
> +   VMXNET3_CMD_RESERVED10,
> +   VMXNET3_CMD_SET_RING_BUFFER_SIZE,
>  
>     VMXNET3_CMD_FIRST_GET = 0xF00D0000,
>     VMXNET3_CMD_GET_QUEUE_STATUS = VMXNET3_CMD_FIRST_GET,
> @@ -822,6 +825,17 @@ typedef enum Vmxnet3_RSSField {
>     VMXNET3_RSS_FIELDS_ESPIP6 = 0x0020,
>  } Vmxnet3_RSSField;
>  
> +typedef
> +#include "vmware_pack_begin.h"
> +struct Vmxnet3_RingBufferSize {
> +	__le16      ring1BufSizeType0;
> +	__le16      ring1BufSizeType1;
> +	__le16      ring2BufSizeType1;
> +	__le16      pad;
> +}
> +#include "vmware_pack_end.h"
> +Vmxnet3_RingBufferSize;
> +

As far as I can see these "vmware_pack_begin.h" & "vmware_pack_end.h"
has only file license comment, and I can see this is used in a few other
type declaration.

What is the reasoning behind using these headers?