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

From: Greg KH
Date: Tue Sep 28 2021 - 00:39:40 EST


On Mon, Sep 27, 2021 at 04:20:25PM -0700, Sohil Mehta wrote:
> On 9/23/2021 5:26 AM, Greg KH wrote:
> > On Mon, Sep 13, 2021 at 01:01:25PM -0700, Sohil Mehta wrote:
> > > +
> > > +/* 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