Greg Kurz's on July 18, 2019 3:00 am:
> On Wed, 17 Jul 2019 15:39:51 +1000
> Nicholas Piggin <npig...@gmail.com> wrote:
>
>> This does not do directed yielding and is not quite as strict as PAPR
>> specifies in terms of precise dispatch behaviour. This generally will
>> mean suboptimal performance, rather than guest misbehaviour. Linux
>> does not rely on exact dispatch behaviour.
>>
>> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
>> ---
>
> LGTM.
>
> Reviewed-by: Greg Kurz <gr...@kaod.org>
>
> Just two minor comments, see below.
>
>> Changes since v4:
>> - Style, added justification comments, spelling.
>> - Fixed trying to dereference spapr_cpu for a -1 target.
>>
>> hw/ppc/spapr_hcall.c | 68 ++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 68 insertions(+)
>>
>> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
>> index 8b208ab259..5e655172b2 100644
>> --- a/hw/ppc/spapr_hcall.c
>> +++ b/hw/ppc/spapr_hcall.c
>> @@ -1069,6 +1069,73 @@ static target_ulong h_cede(PowerPCCPU *cpu,
>> SpaprMachineState *spapr,
>> return H_SUCCESS;
>> }
>>
>> +static target_ulong h_confer(PowerPCCPU *cpu, SpaprMachineState *spapr,
>> + target_ulong opcode, target_ulong *args)
>> +{
>> + target_long target = args[0];
>> + uint32_t dispatch = args[1];
>> + CPUState *cs = CPU(cpu);
>> + SpaprCpuState *spapr_cpu;
>> +
>> + /*
>> + * -1 means confer to all other CPUs without dispatch counter check,
>> + * otherwise it's a targeted confer.
>> + */
>> + if (target != -1) {
>> + PowerPCCPU *target_cpu = spapr_find_cpu(target);
>> + CPUState *target_cs = CPU(target_cpu);
>> + unsigned int target_dispatch;
>
> Maybe make it uint32_t to be consistent with dispatch above, and this
> is the actual return type of ldl_be_phys() ?
Sure okay.
>> +
>> + if (!target_cs) {
>
> This is the only user of target_cs, maybe drop it and use target_cpu
> instead ?
That probably works, I'll try.
Thanks,
Nick
