On Mon, Aug 26, 2013 at 02:24:49PM +0200, Alexander Graf wrote:
>
> On 23.08.2013, at 13:30, Alexey Kardashevskiy wrote:
>
> > PAPR+ requires two RTAS calls to be supported by the hypervisor in
> > order to allow hotplugging VCPUs from the guest. The "start-cpu" RTAS
> > call was already there but "stop-self" was not.
> >
> > This adds the "stop-self" RTAS call.
> >
> > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
> > ---
> > hw/ppc/spapr_rtas.c | 14 ++++++++++++++
> > 1 file changed, 14 insertions(+)
> >
> > diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
> > index 394ce05..8a4cfa0 100644
> > --- a/hw/ppc/spapr_rtas.c
> > +++ b/hw/ppc/spapr_rtas.c
> > @@ -202,6 +202,19 @@ static void rtas_start_cpu(PowerPCCPU *cpu_,
> > sPAPREnvironment *spapr,
> > rtas_st(rets, 0, -3);
> > }
> >
> > +static void rtas_stop_self(PowerPCCPU *cpu, sPAPREnvironment *spapr,
> > + uint32_t token, uint32_t nargs,
> > + target_ulong args,
> > + uint32_t nret, target_ulong rets)
> > +{
> > + CPUState *cs = CPU(cpu);
> > + CPUPPCState *env = &cpu->env;
> > +
> > + cs->halted = 1;
> > + env->msr = 0;
>
> So this is here to make sure we don't accidentally get out of halted state by
> an interrupt on that vcpu. Could you please somehow make that part obvious?
> Either by adding a comment or by only explicitly masking DEC and EE and a
> comment :).
>
> > + cs->exit_request = 1;
>
> This should probably be qemu_cpu_kick_self().
Uh, no, I don't think so. This is there purely to make sure we exit
the inner loop, and actually test cpu_can_run() which will test
halted. AFAICT qemu_cpu_kick_self() won't do anything similar.
--
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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