> -----Original Message-----
> From: Stephen Hemminger <[email protected]>
> Sent: Monday, September 21, 2026 2:10 AM
> To: [email protected]
> Cc: Stephen Hemminger <[email protected]>; Wei Hu
> <[email protected]>
> Subject: [EXTERNAL] [PATCH v2 02/33] bus/vmbus: remove packed attribute
> from ring buffer
>
> The attribute came from the FreeBSD structure this was copied from, which
> ends in a flexible array member for the ring data and is asserted to be page
> sized. DPDK computes the data offset from the page size instead and never
> declared that member, so nothing is left that packing affects: all remaining
> members are naturally aligned and the layout is identical without it.
>
> Byte alignment does prevent atomic access to the ring indexes, which clang
> rejects with -Watomic-alignment.
>
> Signed-off-by: Stephen Hemminger <[email protected]>
Reviewed-by: [email protected]
> ---
> drivers/bus/vmbus/rte_vmbus_reg.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/bus/vmbus/rte_vmbus_reg.h
> b/drivers/bus/vmbus/rte_vmbus_reg.h
> index 6370a07f95..210328c877 100644
> --- a/drivers/bus/vmbus/rte_vmbus_reg.h
> +++ b/drivers/bus/vmbus/rte_vmbus_reg.h
> @@ -69,7 +69,7 @@ struct __rte_packed_begin vmbus_mon_page {
> * Buffer ring
> */
>
> -struct __rte_packed_begin vmbus_bufring {
> +struct vmbus_bufring {
> volatile uint32_t windex;
> volatile uint32_t rindex;
>
> @@ -111,7 +111,7 @@ struct __rte_packed_begin vmbus_bufring {
> * page aligned and starts at rte_mem_page_size() from the beginning
> * of this structure
> */
> -} __rte_packed_end;
> +};
>
> /*
> * Channel packets
> --
> 2.53.0
