Re: [Qemu-devel] [PATCH-for-4.2 v1 2/6] s390x/tcg: Rework MMU selection for instruction fetches

[Cornelia Huck <cohuck@redhat.com>]

On Mon, 12 Aug 2019 15:37:39 +0200
David Hildenbrand <david@redhat.com> wrote:

> On 12.08.19 13:27, David Hildenbrand wrote:
> > Instructions are always fetched from primary address space, except when
> > in home address mode. Perform the selection directly in cpu_mmu_index().
> > 
> > get_mem_index() is only used to perform data access, instructions are
> > fetched via cpu_lduw_code(), which translates to cpu_mmu_index(env, true).
> > 
> > We don't care about restricting the access permissions of the TLB
> > entries anymore, as we no longer enter PRIMARY entries into the
> > SECONDARY MMU. Cleanup related code a bit.
> > 
> > Signed-off-by: David Hildenbrand <david@redhat.com>
> > ---
> >  target/s390x/cpu.h        |  7 +++++++
> >  target/s390x/mmu_helper.c | 35 ++++++++++++++---------------------
> >  2 files changed, 21 insertions(+), 21 deletions(-)
> > 
> > diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h
> > index a606547b4d..c34992bb2e 100644
> > --- a/target/s390x/cpu.h
> > +++ b/target/s390x/cpu.h
> > @@ -332,6 +332,13 @@ static inline int cpu_mmu_index(CPUS390XState *env, bool ifetch)
> >          return MMU_REAL_IDX;
> >      }
> >  
> > +    if (ifetch) {
> > +        if ((env->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME) {
> > +            return MMU_HOME_IDX;
> > +        }
> > +        return MMU_PRIMARY_IDX;
> > +    }
> > +
> >      switch (env->psw.mask & PSW_MASK_ASC) {
> >      case PSW_ASC_PRIMARY:
> >          return MMU_PRIMARY_IDX;
> > diff --git a/target/s390x/mmu_helper.c b/target/s390x/mmu_helper.c
> > index 6e9c4d6151..2c9bb3acc0 100644
> > --- a/target/s390x/mmu_helper.c
> > +++ b/target/s390x/mmu_helper.c
> > @@ -349,6 +349,7 @@ int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,
> >  {
> >      static S390SKeysState *ss;
> >      static S390SKeysClass *skeyclass;
> > +    uint64_t asce;
> >      int r = -1;  
> 
> I can now stop initializing r.
> 
> >      uint8_t key;
> >  
> > @@ -381,35 +382,21 @@ int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t asc,
> >      if (!(env->psw.mask & PSW_MASK_DAT)) {
> >          *raddr = vaddr;
> >          r = 0;  
> 
> and this can go as well.
> 
> > -        goto out;
> > +        goto nodat;
> >      }
> >    
> 
> 

So, there will be a v2?