Re: [Qemu-devel] [PATCH v2 1/9] drivers/hv: replace enum hv_message_type by u32

[Denis V. Lunev]

On 12/02/2015 03:22 PM, Paolo Bonzini wrote:
> On 30/11/2015 17:22, Andrey Smetanin wrote:
> > enum hv_message_type inside struct hv_message, hv_post_message
> > is not size portable. Replace enum by u32.
> It's only non-portable inside structs.  Okay to apply just these:
>
> @@ -172,7 +174,7 @@ union hv_message_flags {
>
>   /* Define synthetic interrupt controller message header. */
>   struct hv_message_header {
> -       u32 message_type;
> +       enum hv_message_type message_type;
>         u8 payload_size;
>         union hv_message_flags message_flags;
>         u8 reserved[2];
> @@ -345,7 +347,7 @@ enum hv_call_code {
>   struct hv_input_post_message {
>         union hv_connection_id connectionid;
>         u32 reserved;
> -       u32 message_type;
> +       enum hv_message_type message_type;
>         u32 payload_size;
>         u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
>   };
>
> ?
>
> Paolo
sorry for the delay.

Andrey is on vacation till the end of the week.

This could be not enough for some compilers as this exact
enum could be signed and unsigned depends upon the
implementation of the compiler and if it is signed we
can face signed/unsigned comparison in ifs.

Vitaly, by the way, this code is a bit rotten. The only caller of
hv_post_message calls it with message type exactly written
as "1", which is not defined in the enum.

/*
 * vmbus_post_msg - Send a msg on the vmbus's message connection
 */
int vmbus_post_msg(void *buffer, size_t buflen)
{
    ...
    ret = hv_post_message(conn_id, 1, buffer, buflen);

Den