Re: [Qemu-ppc] [PATCH v10 6/6] ppc: spapr: Handle "ibm, nmi-register" and "ibm, nmi-interlock" RTAS calls

[Aravinda Prasad]

On Tuesday 25 June 2019 12:30 PM, Greg Kurz wrote:
> On Tue, 25 Jun 2019 11:46:06 +0530
> Aravinda Prasad <address@hidden> wrote:
> 
>> On Monday 24 June 2019 07:59 PM, Greg Kurz wrote:
>>> On Wed, 12 Jun 2019 14:51:38 +0530
>>> Aravinda Prasad <address@hidden> wrote:
>>>   
>>>> This patch adds support in QEMU to handle "ibm,nmi-register"
>>>> and "ibm,nmi-interlock" RTAS calls and sets the default
>>>> value of SPAPR_CAP_FWNMI_MCE to SPAPR_CAP_ON for machine
>>>> type 4.0.
>>>>  
>>>
>>> Next machine type is 4.1.  
>>
>> ok.
>>
>>>   
>>>> The machine check notification address is saved when the
>>>> OS issues "ibm,nmi-register" RTAS call.
>>>>
>>>> This patch also handles the case when multiple processors
>>>> experience machine check at or about the same time by
>>>> handling "ibm,nmi-interlock" call. In such cases, as per
>>>> PAPR, subsequent processors serialize waiting for the first
>>>> processor to issue the "ibm,nmi-interlock" call. The second
>>>> processor that also received a machine check error waits
>>>> till the first processor is done reading the error log.
>>>> The first processor issues "ibm,nmi-interlock" call
>>>> when the error log is consumed.
>>>>
>>>> Signed-off-by: Aravinda Prasad <address@hidden>
>>>> ---
>>>>  hw/ppc/spapr.c         |    6 ++++-
>>>>  hw/ppc/spapr_rtas.c    |   63 
>>>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>>>  include/hw/ppc/spapr.h |    5 +++-
>>>>  3 files changed, 72 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
>>>> index 3d6d139..213d493 100644
>>>> --- a/hw/ppc/spapr.c
>>>> +++ b/hw/ppc/spapr.c
>>>> @@ -2946,6 +2946,9 @@ static void spapr_machine_init(MachineState *machine)
>>>>          /* Create the error string for live migration blocker */
>>>>          error_setg(&spapr->fwnmi_migration_blocker,
>>>>                  "Live migration not supported during machine check 
>>>> handling");
>>>> +
>>>> +        /* Register ibm,nmi-register and ibm,nmi-interlock RTAS calls */
>>>> +        spapr_fwnmi_register();  
>>>
>>> IIRC this was supposed to depend on SPAPR_CAP_FWNMI_MCE being ON.  
>>
>> Yes this is inside SPAPR_CAP_FWNMI_MCE check:
>>
>> if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI_MCE) == SPAPR_CAP_ON) {
>>     /*
>>      * Ensure that the rtas image size is less than RTAS_ERROR_LOG_OFFSET
>>      * or else the rtas image will be overwritten with the rtas error log
>>      * when a machine check exception is encountered.
>>      */
>>     g_assert(spapr->rtas_size < RTAS_ERROR_LOG_OFFSET);
>>
>>     /* Resize rtas blob to accommodate error log */
>>     spapr->rtas_size = RTAS_ERROR_LOG_MAX;
>>
>>     /* Create the error string for live migration blocker */
>>     error_setg(&spapr->fwnmi_migration_blocker,
>>             "Live migration not supported during machine check handling");
>>
>>     /* Register ibm,nmi-register and ibm,nmi-interlock RTAS calls */
>>     spapr_fwnmi_register();
>> }
>>
> 
> Oops my bad... sorry for the noise.
> 
>>
>>>   
>>>>      }
>>>>  
>>>>      spapr->rtas_blob = g_malloc(spapr->rtas_size);
>>>> @@ -4408,7 +4411,7 @@ static void spapr_machine_class_init(ObjectClass 
>>>> *oc, void *data)
>>>>      smc->default_caps.caps[SPAPR_CAP_NESTED_KVM_HV] = SPAPR_CAP_OFF;
>>>>      smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
>>>>      smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_OFF;
>>>> -    smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_OFF;
>>>> +    smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_ON;
>>>>      spapr_caps_add_properties(smc, &error_abort);
>>>>      smc->irq = &spapr_irq_dual;
>>>>      smc->dr_phb_enabled = true;
>>>> @@ -4512,6 +4515,7 @@ static void 
>>>> spapr_machine_3_1_class_options(MachineClass *mc)
>>>>      smc->default_caps.caps[SPAPR_CAP_SBBC] = SPAPR_CAP_BROKEN;
>>>>      smc->default_caps.caps[SPAPR_CAP_IBS] = SPAPR_CAP_BROKEN;
>>>>      smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_OFF;
>>>> +    smc->default_caps.caps[SPAPR_CAP_FWNMI_MCE] = SPAPR_CAP_OFF;  
>>>
>>> This should have been put into spapr_machine_4_0_class_options().  
>>
>> ok. I will change it.
>>
>>>
>>> But unless you manage to get this merged before soft-freeze (2019-07-02),
>>> I'm afraid this will be a 4.2 feature.  
>>
>> If there are no other comments, can this be merged to 4.1? I will send a
>> revised version with the above changes.
>>
> 
> This is David's call.

David, can you let me know if this can be merged to 4.1 with the above
minor changes?

> 
>> Regards,
>> Aravinda
>>
>>>   
>>>>  }
>>>>  
>>>>  DEFINE_SPAPR_MACHINE(3_1, "3.1", false);
>>>> diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c
>>>> index a015a80..e010cb2 100644
>>>> --- a/hw/ppc/spapr_rtas.c
>>>> +++ b/hw/ppc/spapr_rtas.c
>>>> @@ -49,6 +49,7 @@
>>>>  #include "hw/ppc/fdt.h"
>>>>  #include "target/ppc/mmu-hash64.h"
>>>>  #include "target/ppc/mmu-book3s-v3.h"
>>>> +#include "migration/blocker.h"
>>>>  
>>>>  static void rtas_display_character(PowerPCCPU *cpu, SpaprMachineState 
>>>> *spapr,
>>>>                                     uint32_t token, uint32_t nargs,
>>>> @@ -352,6 +353,60 @@ static void rtas_get_power_level(PowerPCCPU *cpu, 
>>>> SpaprMachineState *spapr,
>>>>      rtas_st(rets, 1, 100);
>>>>  }
>>>>  
>>>> +static void rtas_ibm_nmi_register(PowerPCCPU *cpu,
>>>> +                                  SpaprMachineState *spapr,
>>>> +                                  uint32_t token, uint32_t nargs,
>>>> +                                  target_ulong args,
>>>> +                                  uint32_t nret, target_ulong rets)
>>>> +{
>>>> +    int ret;
>>>> +    hwaddr rtas_addr = spapr_get_rtas_addr();
>>>> +
>>>> +    if (!rtas_addr) {
>>>> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI_MCE) == SPAPR_CAP_OFF) {
>>>> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    ret = kvmppc_fwnmi_enable(cpu);
>>>> +    if (ret == 1) {
>>>> +        rtas_st(rets, 0, RTAS_OUT_NOT_SUPPORTED);
>>>> +        return;
>>>> +    } else if (ret < 0) {
>>>> +        error_report("Couldn't enable KVM FWNMI capability");
>>>> +        rtas_st(rets, 0, RTAS_OUT_HW_ERROR);
>>>> +        return;
>>>> +    }
>>>> +
>>>> +    spapr->guest_machine_check_addr = rtas_ld(args, 1);
>>>> +    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
>>>> +}
>>>> +
>>>> +static void rtas_ibm_nmi_interlock(PowerPCCPU *cpu,
>>>> +                                   SpaprMachineState *spapr,
>>>> +                                   uint32_t token, uint32_t nargs,
>>>> +                                   target_ulong args,
>>>> +                                   uint32_t nret, target_ulong rets)
>>>> +{
>>>> +    if (spapr->guest_machine_check_addr == -1) {
>>>> +        /* NMI register not called */
>>>> +        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
>>>> +    } else {
>>>> +        /*
>>>> +         * vCPU issuing "ibm,nmi-interlock" is done with NMI handling,
>>>> +         * hence unset mc_status.
>>>> +         */
>>>> +        spapr->mc_status = -1;
>>>> +        qemu_cond_signal(&spapr->mc_delivery_cond);
>>>> +        migrate_del_blocker(spapr->fwnmi_migration_blocker);
>>>> +        rtas_st(rets, 0, RTAS_OUT_SUCCESS);
>>>> +    }
>>>> +}
>>>> +
>>>>  static struct rtas_call {
>>>>      const char *name;
>>>>      spapr_rtas_fn fn;
>>>> @@ -496,6 +551,14 @@ hwaddr spapr_get_rtas_addr(void)
>>>>      return (hwaddr)fdt32_to_cpu(*rtas_data);
>>>>  }
>>>>  
>>>> +void spapr_fwnmi_register(void)
>>>> +{
>>>> +    spapr_rtas_register(RTAS_IBM_NMI_REGISTER, "ibm,nmi-register",
>>>> +                        rtas_ibm_nmi_register);
>>>> +    spapr_rtas_register(RTAS_IBM_NMI_INTERLOCK, "ibm,nmi-interlock",
>>>> +                        rtas_ibm_nmi_interlock);
>>>> +}
>>>> +
>>>>  static void core_rtas_register_types(void)
>>>>  {
>>>>      spapr_rtas_register(RTAS_DISPLAY_CHARACTER, "display-character",
>>>> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
>>>> index 0dedf0a..7ae53e2 100644
>>>> --- a/include/hw/ppc/spapr.h
>>>> +++ b/include/hw/ppc/spapr.h
>>>> @@ -637,8 +637,10 @@ target_ulong spapr_hypercall(PowerPCCPU *cpu, 
>>>> target_ulong opcode,
>>>>  #define RTAS_IBM_CREATE_PE_DMA_WINDOW           (RTAS_TOKEN_BASE + 0x27)
>>>>  #define RTAS_IBM_REMOVE_PE_DMA_WINDOW           (RTAS_TOKEN_BASE + 0x28)
>>>>  #define RTAS_IBM_RESET_PE_DMA_WINDOW            (RTAS_TOKEN_BASE + 0x29)
>>>> +#define RTAS_IBM_NMI_REGISTER                   (RTAS_TOKEN_BASE + 0x2A)
>>>> +#define RTAS_IBM_NMI_INTERLOCK                  (RTAS_TOKEN_BASE + 0x2B)
>>>>  
>>>> -#define RTAS_TOKEN_MAX                          (RTAS_TOKEN_BASE + 0x2A)
>>>> +#define RTAS_TOKEN_MAX                          (RTAS_TOKEN_BASE + 0x2C)
>>>>  
>>>>  /* RTAS ibm,get-system-parameter token values */
>>>>  #define RTAS_SYSPARM_SPLPAR_CHARACTERISTICS      20
>>>> @@ -894,4 +896,5 @@ void spapr_check_pagesize(SpaprMachineState *spapr, 
>>>> hwaddr pagesize,
>>>>  
>>>>  void spapr_set_all_lpcrs(target_ulong value, target_ulong mask);
>>>>  hwaddr spapr_get_rtas_addr(void);
>>>> +void spapr_fwnmi_register(void);
>>>>  #endif /* HW_SPAPR_H */
>>>>  
>>>   
>>
> 
> 

-- 
Regards,
Aravinda