Re: [PATCH v4 01/18] xen/riscv: detect and initialize G-stage mode

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

On 9/24/25 1:31 PM, Oleksii Kurochko wrote:

> > > --- a/xen/arch/riscv/setup.c
> > > +++ b/xen/arch/riscv/setup.c
> > > @@ -22,6 +22,7 @@
> > >  #include <asm/early_printk.h>
> > >  #include <asm/fixmap.h>
> > >  #include <asm/intc.h>
> > > +#include <asm/p2m.h>
> > >  #include <asm/sbi.h>
> > >  #include <asm/setup.h>
> > >  #include <asm/traps.h>
> > > @@ -148,6 +149,8 @@ void __init noreturn start_xen(unsigned long bootcpu_id,
> > >  
> > >      console_init_postirq();
> > >  
> > > +    gstage_mode_detect();
> > >         
> > I find it odd for something as fine grained as this to be called from top-
> > level start_xen(). Imo this wants to be a sub-function of whatever does
> > global paging and/or p2m preparations (or even more generally guest ones).
> >       
> It makes sense. I will move the call to gstage_mode_detect() into p2m_init()
> when the latter is introduced.
> Probably, I will move the current patch after p2m_init() is introduced to make
> gstage_mode_detect() static function.
>     
Maybe putting gstage_mode_detect() into p2m_init() is not a good idea, since it
is called during domain creation. I am not sure there is any point in calling
gstage_mode_detect() each time.

It seems that gstage_mode_detect() should be called once during physical CPU
initialization.

A sub-function (riscv_hart_mm_init()? probably, riscv should be dropped from
the name) could be added in setup.c and then called in start_xen(), but
is it really needed a separate sub-function for something that will be called
once per initialization of pCPU?

~ Oleksii