Re: [PATCH v1 07/14] xen/riscv: introduce exception handlers implementation

[Oleksii <oleksii.kurochko@xxxxxxxxx>]

On Mon, 2023-01-23 at 12:17 +0100, Jan Beulich wrote:
> On 20.01.2023 15:59, Oleksii Kurochko wrote:
> > --- /dev/null
> > +++ b/xen/arch/riscv/entry.S
> > @@ -0,0 +1,97 @@
> > +#include <asm/asm.h>
> > +#include <asm/processor.h>
> > +#include <asm/riscv_encoding.h>
> > +#include <asm/traps.h>
> > +
> > +        .global handle_exception
> > +        .align 4
> > +
> > +handle_exception:
> > +
> > +    /* Exceptions from xen */
> > +save_to_stack:
> > +        /* Save context to stack */
> > +        REG_S   sp, (RISCV_CPU_USER_REGS_OFFSET(sp) -
> > RISCV_CPU_USER_REGS_SIZE) (sp)
> > +        addi    sp, sp, -RISCV_CPU_USER_REGS_SIZE
> > +        REG_S   t0, RISCV_CPU_USER_REGS_OFFSET(t0)(sp)
> > +        j       save_context
> > +
> > +save_context:
> 
> Just curious: Why not simply fall through here, i.e. why the J which
> really
> is a NOP in this case?
> 
There is no any specific reason.
I left it for future.
Will remove it in the next patch version.
> Jan