Re: [PATCH v2 1/4] target/ppc: Fix POWER9 radix guest HV interrupt AIL behaviour

[David Gibson]

On Thu, Apr 15, 2021 at 09:12:21AM -0300, Fabiano Rosas wrote:
> Nicholas Piggin <npiggin@gmail.com> writes:
> 
> > ISA v3.0 radix guest execution has a quirk in AIL behaviour such that
> > the LPCR[AIL] value can apply to hypervisor interrupts.
> >
> > This affects machines that emulate HV=1 mode (i.e., powernv9).
> >
> > Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> 
> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>

Applied to ppc-for-6.1.

> 
> > ---
> >  target/ppc/excp_helper.c | 17 +++++++++++++----
> >  1 file changed, 13 insertions(+), 4 deletions(-)
> >
> > diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
> > index 85de7e6c90..b8881c0f85 100644
> > --- a/target/ppc/excp_helper.c
> > +++ b/target/ppc/excp_helper.c
> > @@ -791,14 +791,23 @@ static inline void powerpc_excp(PowerPCCPU *cpu, int 
> > excp_model, int excp)
> >  #endif
> >  
> >      /*
> > -     * AIL only works if there is no HV transition and we are running
> > -     * with translations enabled
> > +     * AIL only works if MSR[IR] and MSR[DR] are both enabled.
> >       */
> > -    if (!((msr >> MSR_IR) & 1) || !((msr >> MSR_DR) & 1) ||
> > -        ((new_msr & MSR_HVB) && !(msr & MSR_HVB))) {
> > +    if (!((msr >> MSR_IR) & 1) || !((msr >> MSR_DR) & 1)) {
> >          ail = 0;
> >      }
> >  
> > +    /*
> > +     * AIL does not work if there is a MSR[HV] 0->1 transition and the
> > +     * partition is in HPT mode. For radix guests, such interrupts are
> > +     * allowed to be delivered to the hypervisor in ail mode.
> > +     */
> > +    if ((new_msr & MSR_HVB) && !(msr & MSR_HVB)) {
> > +        if (!(env->spr[SPR_LPCR] & LPCR_HR)) {
> > +            ail = 0;
> > +        }
> > +    }
> > +
> >      vector = env->excp_vectors[excp];
> >      if (vector == (target_ulong)-1ULL) {
> >          cpu_abort(cs, "Raised an exception without defined vector %d\n",
> 

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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