Re: [PATCH] accel/tcg: Add stub for probe_access()

[Philippe Mathieu-Daudé]

On Thu, Apr 23, 2020 at 9:49 AM David Hildenbrand <address@hidden> wrote:
>
> On 23.04.20 09:10, Philippe Mathieu-Daudé wrote:
> > The TCG helpers where added in b92e5a22ec3 in softmmu_template.h.
> > probe_write() was added in there in 3b4afc9e75a to be moved out
> > to accel/tcg/cputlb.c in 3b08f0a9254, and was later refactored
> > as probe_access() in c25c283df0f.
> > Since it is a TCG specific helper, add a stub to avoid failures
> > when building without TCG, such:
> >
> >   target/arm/helper.o: In function `probe_read':
> >   include/exec/exec-all.h:345: undefined reference to `probe_access'
>
> I think you're missing the most important commit:
>
> 0d57b4999220 ("target/arm: Add support for DC CVAP & DC CVADP ins")
>
> I do wonder if dccvap_writefn() and calling code should be compiled for
> TCG only (CONFIG_TCG). I assume it is only called from TCG code -
> otherwise it would already be semi-broken.

I can only recommend you to read the thread after this previous patch,
as I don't have the knowledge to explain...:
https://www.mail-archive.com/address@hidden/msg689115.html

>
> >
> > Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> > ---
> > Cc: Richard Henderson <address@hidden>
> > Cc: Emilio G. Cota <address@hidden>
> > Cc: Alex Bennée <address@hidden>
> > Cc: David Hildenbrand <address@hidden>
> > ---
> >  accel/stubs/tcg-stub.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/accel/stubs/tcg-stub.c b/accel/stubs/tcg-stub.c
> > index 677191a69c..e4bbf997aa 100644
> > --- a/accel/stubs/tcg-stub.c
> > +++ b/accel/stubs/tcg-stub.c
> > @@ -22,3 +22,10 @@ void tb_flush(CPUState *cpu)
> >  void tlb_set_dirty(CPUState *cpu, target_ulong vaddr)
> >  {
> >  }
> > +
> > +void *probe_access(CPUArchState *env, target_ulong addr, int size,
> > +                   MMUAccessType access_type, int mmu_idx, uintptr_t 
> > retaddr)
> > +{
> > +     /* Handled by hardware accelerator. */
> > +     g_assert_not_reached();
> > +}
> >
>
> Still, this makes sense to me as well
>
> Reviewed-by: David Hildenbrand <address@hidden>
>
> --
> Thanks,
>
> David / dhildenb
>