Re: [PATCH v9 09/15] s390x: protvirt: Set guest IPL PSW

[Claudio Imbrenda <imbrenda@linux.ibm.com>]

On Fri, 13 Mar 2020 15:21:07 +0100
Janosch Frank <frankja@linux.ibm.com> wrote:

> On 3/13/20 1:57 PM, Claudio Imbrenda wrote:
> > On Wed, 11 Mar 2020 09:21:45 -0400
> > Janosch Frank <frankja@linux.ibm.com> wrote:
> >   
> >> Handling of CPU reset and setting of the IPL psw from guest
> >> storage at offset 0 is done by a Ultravisor call. Let's only fetch
> >> it if necessary.
> >>
> >> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> >> Reviewed-by: Thomas Huth <thuth@redhat.com>
> >> Reviewed-by: David Hildenbrand <david@redhat.com>
> >> ---
> >>  target/s390x/cpu.c | 22 +++++++++++++---------
> >>  1 file changed, 13 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
> >> index 84029f14814b4980..a48d39f139cdc1c4 100644
> >> --- a/target/s390x/cpu.c
> >> +++ b/target/s390x/cpu.c
> >> @@ -78,16 +78,20 @@ static bool s390_cpu_has_work(CPUState *cs)
> >>  static void s390_cpu_load_normal(CPUState *s)
> >>  {
> >>      S390CPU *cpu = S390_CPU(s);
> >> -    uint64_t spsw = ldq_phys(s->as, 0);
> >> -
> >> -    cpu->env.psw.mask = spsw & PSW_MASK_SHORT_CTRL;
> >> -    /*
> >> -     * Invert short psw indication, so SIE will report a
> >> specification
> >> -     * exception if it was not set.
> >> -     */
> >> -    cpu->env.psw.mask ^= PSW_MASK_SHORTPSW;
> >> -    cpu->env.psw.addr = spsw & PSW_MASK_SHORT_ADDR;
> >> +    uint64_t spsw;
> >>  
> >> +    if (!s390_is_pv()) {
> >> +        spsw = ldq_phys(s->as, 0);
> >> +        cpu->env.psw.mask = spsw & PSW_MASK_SHORT_CTRL;
> >> +        /*
> >> +         * Invert short psw indication, so SIE will report a
> >> specification
> >> +         * exception if it was not set.
> >> +         */
> >> +        cpu->env.psw.mask ^= PSW_MASK_SHORTPSW;
> >> +        cpu->env.psw.addr = spsw & PSW_MASK_SHORT_ADDR;
> >> +    } else {
> >> +        s390_cpu_set_state(S390_CPU_STATE_LOAD, cpu);
> >> +    }
> >>      s390_cpu_set_state(S390_CPU_STATE_OPERATING, cpu);
> >>  }
> >>  #endif  
> > 
> > I don't understand why you set the state to S390_CPU_STATE_LOAD and
> > then immediately afterwards to S390_CPU_STATE_OPERATING, especially
> > considering that both do the same
> >   
> 
> Have a look at the specs, wee need to set the load state before
> setting the cpu to operating.
> 
> I can add a comment to make it clearer if you want.

once you have added the comment, you can also add:

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>