[PATCH 15/15] examples: pack structures when building with MSVC

[Bruce Richardson]

On Wed, Mar 20, 2024 at 02:06:11PM -0700, Tyler Retzlaff wrote:
> Add __rte_msvc_pushpack(1) to all __rte_packed structs to cause packing
> when building with MSVC.
> 
> Signed-off-by: Tyler Retzlaff <roretzla at linux.microsoft.com>
> ---
>  examples/common/neon/port_group.h | 1 +
>  examples/ip_pipeline/cli.c        | 5 +++++
>  examples/ipsec-secgw/ipsec.h      | 1 +
>  examples/l3fwd-power/main.c       | 2 ++
>  examples/ptpclient/ptpclient.c    | 8 ++++++++
>  5 files changed, 17 insertions(+)
> 
> diff --git a/examples/common/neon/port_group.h b/examples/common/neon/port_group.h
> index 421e2e8..bd40590 100644
> --- a/examples/common/neon/port_group.h
> +++ b/examples/common/neon/port_group.h
> @@ -21,6 +21,7 @@
>  port_groupx4(uint16_t pn[FWDSTEP + 1], uint16_t *lp, uint16x8_t dp1,
>  		  uint16x8_t dp2)
>  {
> +	__rte_msvc_pack
>  	union {
>  		uint16_t u16[FWDSTEP + 1];
>  		uint64_t u64;
> diff --git a/examples/ip_pipeline/cli.c b/examples/ip_pipeline/cli.c
> index e8269ea..cae5c1f 100644
> --- a/examples/ip_pipeline/cli.c
> +++ b/examples/ip_pipeline/cli.c
> @@ -2566,6 +2566,7 @@
>   *    | lpm
>   *       ipv4 | ipv6 <addr> <depth>
>   */
> +__rte_msvc_pack
>  struct pkt_key_qinq {
>  	uint16_t ethertype_svlan;
>  	uint16_t svlan;
> @@ -2573,6 +2574,7 @@ struct pkt_key_qinq {
>  	uint16_t cvlan;
>  } __rte_packed;
>  
> +__rte_msvc_pack
>  struct pkt_key_ipv4_5tuple {
>  	uint8_t time_to_live;
>  	uint8_t proto;
> @@ -2583,6 +2585,7 @@ struct pkt_key_ipv4_5tuple {
>  	uint16_t dp;
>  } __rte_packed;
>  
> +__rte_msvc_pack
>  struct pkt_key_ipv6_5tuple {
>  	uint16_t payload_length;
>  	uint8_t proto;
> @@ -2593,10 +2596,12 @@ struct pkt_key_ipv6_5tuple {
>  	uint16_t dp;
>  } __rte_packed;
>  
> +__rte_msvc_pack
>  struct pkt_key_ipv4_addr {
>  	uint32_t addr;
>  } __rte_packed;
>  
> +__rte_msvc_pack
>  struct pkt_key_ipv6_addr {
>  	uint8_t addr[16];
>  } __rte_packed;

These structs don't look to me like they need packing. No padding should
appear between elements of the structs. The last struct definitely doesn't
need it, as it's a uint8_t array.

/Bruce