Re: [RFC PATCH V2 15/18] x86/sev: Add a #HV exception handler

[Tianyu Lan]

On 1/10/2023 8:47 PM, Gupta, Pankaj wrote:
> > + *
> > + * To make this work the #HV entry code tries its best to pretend it 
> > doesn't use
> > + * an IST stack by switching to the task stack if coming from 
> > user-space (which
> > + * includes early SYSCALL entry path) or back to the stack in the 
> > IRET frame if
> > + * entered from kernel-mode.
> > + *
> > + * 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.
>
> Noticed same comment line in the #VC exception handling section (macro 
> idtentry_vc). Just wondering we need to remove this line as the patch 
> being proposed for the #HV exception handling? unless this is planned to 
> be extended in some other way.

Nice catch! Will remove this in the next version.

Thanks.