[PATCH v3 4/9] powerpc/pseries: Send payload with ibm,send-hvpipe-msg RTAS

[Tyrel Datwyler]

On 8/28/25 4:08 PM, Haren Myneni wrote:
> ibm,send-hvpipe-msg RTAS call is used to send data to the source
> (Ex: Hardware Management Console) over the hypervisor pipe. The
> maximum data length of 4048 bytes is supported with this RTAS call
> right now. The user space uses write() to send this payload which
> invokes this RTAS. Then the write returns the buffer length
> (including papr_hvpipe_hdr length) to the user space for success
> or RTAS failure error.
> 
> ibm,send-hvpipe-msg call takes source ID as target and the buffer
> in the form of buffer list. The buffer list format consists of
> work area of size 4K to hold buffer list and number of 4K work
> areas depends on buffers is as follows:
> 
> Length of Buffer List in bytes
> Address of 4K buffer 1
> Length of 4K buffer 1 used
> ...
> Address of 4K buffer n
> Length of 4K buffer n used
> 
> Only one buffer is used right now because of max payload size is
> 4048 bytes. writev() can be used in future when supported more
> than one buffer.
> 
> Signed-off-by: Haren Myneni <haren at linux.ibm.com>
> Reviewed-by: Mahesh Salgaonkar <mahesh at linux.ibm.com>
> Tested-by: Shashank MS <shashank.gowda at in.ibm.com>
> ---

Reviewed-by: Tyrel Datwyler <tyreld at linux.ibm.com>