Re: [Qemu-devel] [PATCH v5 19/36] spapr: add a 'pseries-3.1-xive' machine type

[Cédric Le Goater]

On 11/28/18 5:42 AM, David Gibson wrote:
> On Fri, Nov 16, 2018 at 11:57:12AM +0100, Cédric Le Goater wrote:
>> The interrupt mode is statically defined to XIVE only for this machine.
>> The guest OS is required to have support for the XIVE exploitation
>> mode of the POWER9 interrupt controller.
>>
>> Signed-off-by: Cédric Le Goater <address@hidden>
>> ---
>>  include/hw/ppc/spapr_irq.h |  1 +
>>  hw/ppc/spapr.c             | 36 +++++++++++++++++++++++++++++++-----
>>  hw/ppc/spapr_irq.c         |  3 +++
>>  3 files changed, 35 insertions(+), 5 deletions(-)
>>
>> diff --git a/include/hw/ppc/spapr_irq.h b/include/hw/ppc/spapr_irq.h
>> index c3b4c38145eb..b299dd794bff 100644
>> --- a/include/hw/ppc/spapr_irq.h
>> +++ b/include/hw/ppc/spapr_irq.h
>> @@ -33,6 +33,7 @@ void spapr_irq_msi_reset(sPAPRMachineState *spapr);
>>  typedef struct sPAPRIrq {
>>      uint32_t    nr_irqs;
>>      uint32_t    nr_msis;
>> +    uint8_t     ov5;
> 
> I'm a bit confused as to what exactly this represents..

The option vector 5 bits advertised by CAS for the platform. What the
hypervisor supports.
 
> 
>>      void (*init)(sPAPRMachineState *spapr, int nr_irqs, int nr_servers,
>>                   Error **errp);
>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>> index ad1692cdcd0f..8fbb743769db 100644
>> --- a/hw/ppc/spapr.c
>> +++ b/hw/ppc/spapr.c
>> @@ -1097,12 +1097,14 @@ static void spapr_dt_rtas(sPAPRMachineState *spapr, 
>> void *fdt)
>>      spapr_dt_rtas_tokens(fdt, rtas);
>>  }
>>  
>> -/* Prepare ibm,arch-vec-5-platform-support, which indicates the MMU features
>> - * that the guest may request and thus the valid values for bytes 24..26 of
>> - * option vector 5: */
>> -static void spapr_dt_ov5_platform_support(void *fdt, int chosen)
>> +/* Prepare ibm,arch-vec-5-platform-support, which indicates the MMU
>> + * and the XIVE features that the guest may request and thus the valid
>> + * values for bytes 23..26 of option vector 5: */
>> +static void spapr_dt_ov5_platform_support(sPAPRMachineState *spapr, void 
>> *fdt,
>> +                                          int chosen)
>>  {
>>      PowerPCCPU *first_ppc_cpu = POWERPC_CPU(first_cpu);
>> +    sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
>>  
>>      char val[2 * 4] = {
>>          23, 0x00, /* Xive mode, filled in below. */
>> @@ -1123,7 +1125,11 @@ static void spapr_dt_ov5_platform_support(void *fdt, 
>> int chosen)
>>          } else {
>>              val[3] = 0x00; /* Hash */
>>          }
>> +        /* TODO: test KVM support */
>> +        val[1] = smc->irq->ov5;
>>      } else {
>> +        val[1] = smc->irq->ov5;
> 
> ..here it seems to be a specific value for this OV5 byte, indicating the
> supported intc...

yes.

> 
>> +
>>          /* V3 MMU supports both hash and radix in tcg (with dynamic 
>> switching) */
>>          val[3] = 0xC0;
>>      }
>> @@ -1191,7 +1197,7 @@ static void spapr_dt_chosen(sPAPRMachineState *spapr, 
>> void *fdt)
>>          _FDT(fdt_setprop_string(fdt, chosen, "stdout-path", stdout_path));
>>      }
>>  
>> -    spapr_dt_ov5_platform_support(fdt, chosen);
>> +    spapr_dt_ov5_platform_support(spapr, fdt, chosen);
>>  
>>      g_free(stdout_path);
>>      g_free(bootlist);
>> @@ -2622,6 +2628,11 @@ static void spapr_machine_init(MachineState *machine)
>>      /* advertise support for ibm,dyamic-memory-v2 */
>>      spapr_ovec_set(spapr->ov5, OV5_DRMEM_V2);
>>  
>> +    /* advertise XIVE */
>> +    if (smc->irq->ov5) {
> 
> ..but here it seems to be a bool indicating XIVE support specifically.

ah. yes. I need to check this part. That was a while ago.

>> +        spapr_ovec_set(spapr->ov5, OV5_XIVE_EXPLOIT);
>> +    }
>> +
>>      /* init CPUs */
>>      spapr_init_cpus(spapr);
>>  
>> @@ -3971,6 +3982,21 @@ static void 
>> spapr_machine_3_1_class_options(MachineClass *mc)
>>  
>>  DEFINE_SPAPR_MACHINE(3_1, "3.1", true);
>>  
>> +static void spapr_machine_3_1_xive_instance_options(MachineState *machine)
>> +{
>> +    spapr_machine_3_1_instance_options(machine);
>> +}
>> +
>> +static void spapr_machine_3_1_xive_class_options(MachineClass *mc)
>> +{
>> +    sPAPRMachineClass *smc = SPAPR_MACHINE_CLASS(mc);
>> +
>> +    spapr_machine_3_1_class_options(mc);
>> +    smc->irq = &spapr_irq_xive;
>> +}
>> +
>> +DEFINE_SPAPR_MACHINE(3_1_xive, "3.1-xive", false);
>> +
>>  /*
>>   * pseries-3.0
>>   */
>> diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
>> index 253abc10e780..42e73851b174 100644
>> --- a/hw/ppc/spapr_irq.c
>> +++ b/hw/ppc/spapr_irq.c
>> @@ -210,6 +210,7 @@ static Object 
>> *spapr_irq_cpu_intc_create_xics(sPAPRMachineState *spapr,
>>  sPAPRIrq spapr_irq_xics = {
>>      .nr_irqs     = SPAPR_IRQ_XICS_NR_IRQS,
>>      .nr_msis     = SPAPR_IRQ_XICS_NR_MSIS,
>> +    .ov5         = 0x0, /* XICS only */
>>  
>>      .init        = spapr_irq_init_xics,
>>      .claim       = spapr_irq_claim_xics,
>> @@ -341,6 +342,7 @@ static Object 
>> *spapr_irq_cpu_intc_create_xive(sPAPRMachineState *spapr,
>>  sPAPRIrq spapr_irq_xive = {
>>      .nr_irqs     = SPAPR_IRQ_XIVE_NR_IRQS,
>>      .nr_msis     = SPAPR_IRQ_XIVE_NR_MSIS,
>> +    .ov5         = 0x40, /* XIVE exploitation mode only */
>>  
>>      .init        = spapr_irq_init_xive,
>>      .claim       = spapr_irq_claim_xive,
>> @@ -447,6 +449,7 @@ int spapr_irq_find(sPAPRMachineState *spapr, int num, 
>> bool align, Error **errp)
>>  sPAPRIrq spapr_irq_xics_legacy = {
>>      .nr_irqs     = SPAPR_IRQ_XICS_LEGACY_NR_IRQS,
>>      .nr_msis     = SPAPR_IRQ_XICS_LEGACY_NR_IRQS,
>> +    .ov5         = 0x0, /* XICS only */
>>  
>>      .init        = spapr_irq_init_xics,
>>      .claim       = spapr_irq_claim_xics,
>