Re: [PATCH V4 14/24] arm/ioreq: Introduce arch specific bits for IOREQ/DM features

[Julien Grall <julien@xxxxxxx>]

Hi Stefano,

On 20/01/2021 00:50, Stefano Stabellini wrote:
> On Tue, 19 Jan 2021, Oleksandr wrote:
> > diff --git a/xen/arch/arm/ioreq.c b/xen/arch/arm/ioreq.c
> > index 40b9e59..0508bd8 100644
> > --- a/xen/arch/arm/ioreq.c
> > +++ b/xen/arch/arm/ioreq.c
> > @@ -101,12 +101,10 @@ enum io_state try_fwd_ioserv(struct cpu_user_regs *regs,
> >
> >   bool arch_ioreq_complete_mmio(void)
> >   {
> > -    struct vcpu *v = current;
> >       struct cpu_user_regs *regs = guest_cpu_user_regs();
> >       const union hsr hsr = { .bits = regs->hsr };
> > -    paddr_t addr = v->io.req.addr;
> >
> > -    if ( try_handle_mmio(regs, hsr, addr) == IO_HANDLED )
> > +    if ( handle_ioserv(regs, current) == IO_HANDLED )
> >       {
> >           advance_pc(regs, hsr);
> >           return true;
> Yes, but I think we want to keep the check
>
>      vio->req.state == STATE_IORESP_READY
>
> So maybe (uncompiled, untested):
>
>      if ( v->io.req.state != STATE_IORESP_READY )
>          return false;
Is it possible to reach this function with v->io.req.state != 
STATE_IORESP_READY? If not, then I would suggest to add an 
ASSERT_UNREACHABLE() before the return.
Cheers,

--
Julien Grall