Re: [RFC PATCH V3 12/16] x86/sev: Add a #HV exception handler

[Tianyu Lan]

On 3/31/2023 11:57 PM, Borislav Petkov wrote:
> > + *
> > + * If entered from kernel-mode the return stack is validated first, and if it is
> > + * not safe to use (e.g. because it points to the entry stack) the #HV handler
> > + * will switch to a fall-back stack (HV2) and call a special handler function.
> > + *
> > + * The macro is only used for one vector, but it is planned to be extended in
> > + * the future for the #HV exception.
> > + */
> > +.macro idtentry_hv vector asmsym cfunc
> > +SYM_CODE_START(\asmsym)
> ...
>
> why is this so much duplicated code instead of sharing it with
> idtentry_vc and all the facilities it does?

Hi Boris:
	#VC and #HV use different stack. I try reusing vc code path for #HV 
doesn't work. I will continue to work on this direction and report back 
later. In the RFC v4, I still keep the old version and other patches may 
be reviewed in the parellel.

Thanks.