Re: [RFC PATCH 06/13] x86/uintr: Introduce uintr receiver syscalls

On Mon, Sep 27, 2021 at 04:20:25PM -0700, Sohil Mehta wrote:

On 9/23/2021 5:26 AM, Greg KH wrote:

quoted

On Mon, Sep 13, 2021 at 01:01:25PM -0700, Sohil Mehta wrote:

quoted

+
+/* User Posted Interrupt Descriptor (UPID) */
+struct uintr_upid {
+	struct {
+		u8 status;	/* bit 0: ON, bit 1: SN, bit 2-7: reserved */
+		u8 reserved1;	/* Reserved */
+		u8 nv;		/* Notification vector */
+		u8 reserved2;	/* Reserved */

What are these "reserved" for?

The UPID is an architectural data structure defined by the hardware. The
reserved fields are defined by the hardware (likely to keep the structure
size as 16 bytes).

Then those values must be set to 0, right?  I think I missed the part of
the code that set them, hopefully it's somewhere...

thanks,

greg k-h