Re: [Qemu-ppc] [PATCH v2 1/3] target/ppc: add basic support for PTCR on POWER9

[Cédric Le Goater]

On 02/19/2018 01:21 AM, David Gibson wrote:
> On Fri, Feb 16, 2018 at 09:45:02AM +0100, Cédric Le Goater wrote:
>> The Partition Table Control Register (PTCR) is a hypervisor privileged
>> SPR. It contains the host real address of the Partition Table and its
>> size.
>>
>> Signed-off-by: Cédric Le Goater <address@hidden>
>> ---
>>
>>  Changes since v1:
>>
>>  - renamed partition table definitions to match ISA
>>  - moved definitions under mmu-book3s-v3.h
>>  
>>  target/ppc/cpu.h            |  2 ++
>>  target/ppc/helper.h         |  1 +
>>  target/ppc/misc_helper.c    | 12 ++++++++++++
>>  target/ppc/mmu-book3s-v3.h  |  6 ++++++
>>  target/ppc/mmu_helper.c     | 28 ++++++++++++++++++++++++++++
>>  target/ppc/translate.c      |  3 +++
>>  target/ppc/translate_init.c | 18 ++++++++++++++++++
>>  7 files changed, 70 insertions(+)
>>
>> diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
>> index 9f8cbbe7aa4d..53061229a0a8 100644
>> --- a/target/ppc/cpu.h
>> +++ b/target/ppc/cpu.h
>> @@ -1314,6 +1314,7 @@ int ppc_cpu_handle_mmu_fault(CPUState *cpu, vaddr 
>> address, int size, int rw,
>>  
>>  #if !defined(CONFIG_USER_ONLY)
>>  void ppc_store_sdr1 (CPUPPCState *env, target_ulong value);
>> +void ppc_store_ptcr(CPUPPCState *env, target_ulong value);
>>  #endif /* !defined(CONFIG_USER_ONLY) */
>>  void ppc_store_msr (CPUPPCState *env, target_ulong value);
>>  
>> @@ -1605,6 +1606,7 @@ void ppc_compat_add_property(Object *obj, const char 
>> *name,
>>  #define SPR_BOOKE_GIVOR13     (0x1BC)
>>  #define SPR_BOOKE_GIVOR14     (0x1BD)
>>  #define SPR_TIR               (0x1BE)
>> +#define SPR_PTCR              (0x1D0)
>>  #define SPR_BOOKE_SPEFSCR     (0x200)
>>  #define SPR_Exxx_BBEAR        (0x201)
>>  #define SPR_Exxx_BBTAR        (0x202)
>> diff --git a/target/ppc/helper.h b/target/ppc/helper.h
>> index 5b739179b8b5..19453c68138a 100644
>> --- a/target/ppc/helper.h
>> +++ b/target/ppc/helper.h
>> @@ -709,6 +709,7 @@ DEF_HELPER_FLAGS_1(load_601_rtcu, TCG_CALL_NO_RWG, tl, 
>> env)
>>  #if !defined(CONFIG_USER_ONLY)
>>  #if defined(TARGET_PPC64)
>>  DEF_HELPER_FLAGS_1(load_purr, TCG_CALL_NO_RWG, tl, env)
>> +DEF_HELPER_2(store_ptcr, void, env, tl)
>>  #endif
>>  DEF_HELPER_2(store_sdr1, void, env, tl)
>>  DEF_HELPER_2(store_pidr, void, env, tl)
>> diff --git a/target/ppc/misc_helper.c b/target/ppc/misc_helper.c
>> index 0e4217821b8e..8c8cba5cc6f1 100644
>> --- a/target/ppc/misc_helper.c
>> +++ b/target/ppc/misc_helper.c
>> @@ -88,6 +88,18 @@ void helper_store_sdr1(CPUPPCState *env, target_ulong val)
>>      }
>>  }
>>  
>> +#if defined(TARGET_PPC64)
>> +void helper_store_ptcr(CPUPPCState *env, target_ulong val)
>> +{
>> +    PowerPCCPU *cpu = ppc_env_get_cpu(env);
>> +
>> +    if (env->spr[SPR_PTCR] != val) {
>> +        ppc_store_ptcr(env, val);
>> +        tlb_flush(CPU(cpu));
>> +    }
>> +}
>> +#endif /* defined(TARGET_PPC64) */
>> +
>>  void helper_store_pidr(CPUPPCState *env, target_ulong val)
>>  {
>>      PowerPCCPU *cpu = ppc_env_get_cpu(env);
>> diff --git a/target/ppc/mmu-book3s-v3.h b/target/ppc/mmu-book3s-v3.h
>> index 56095dab522c..fdf80987d7b2 100644
>> --- a/target/ppc/mmu-book3s-v3.h
>> +++ b/target/ppc/mmu-book3s-v3.h
>> @@ -22,6 +22,12 @@
>>  
>>  #ifndef CONFIG_USER_ONLY
>>  
>> +/*
>> + * Partition table definitions
>> + */
>> +#define PTCR_PATB               0x0FFFFFFFFFFFF000ULL /* Partition Table 
>> Base */
>> +#define PTCR_PATS               0x000000000000001FULL /* Partition Table 
>> Size */
>> +
>>  /* Partition Table Entry Fields */
>>  #define PATBE1_GR 0x8000000000000000
>>  
>> diff --git a/target/ppc/mmu_helper.c b/target/ppc/mmu_helper.c
>> index 5568d1642b34..82e63552f617 100644
>> --- a/target/ppc/mmu_helper.c
>> +++ b/target/ppc/mmu_helper.c
>> @@ -2028,6 +2028,34 @@ void ppc_store_sdr1(CPUPPCState *env, target_ulong 
>> value)
>>      env->spr[SPR_SDR1] = value;
>>  }
>>  
>> +#if defined(TARGET_PPC64)
>> +void ppc_store_ptcr(CPUPPCState *env, target_ulong value)
>> +{
>> +    PowerPCCPU *cpu = ppc_env_get_cpu(env);
>> +    qemu_log_mask(CPU_LOG_MMU, "%s: " TARGET_FMT_lx "\n", __func__, value);
>> +
>> +    assert(!cpu->vhyp);
>> +
>> +    if (env->mmu_model & POWERPC_MMU_V3) {
> 
> If it's not MMUv3, the PTCR shouldn't exist, right?  So couldn't this
> just be an assert?

yes. I will change that.

> 
>> +        target_ulong ptcr_mask = PTCR_PATB | PTCR_PATS;
>> +        target_ulong ptas = value & PTCR_PATS;
> 
> Any reason it's "ptas" on the left and "PATS" on the right?

nah. the sed expression I used missed the lower case. 
 
>> +
>> +        if (value & ~ptcr_mask) {
>> +            error_report("Invalid bits 0x"TARGET_FMT_lx" set in PTCR",
>> +                         value & ~ptcr_mask);
>> +            value &= ptcr_mask;
>> +        }
>> +        if (ptas > 28) {

This should be 24.

>> +            error_report("Invalid PTAS 0x" TARGET_FMT_lx" stored in PTCR",
>> +                         ptas);
>> +            return;
>> +        }
> 
> Is masking / ignoring incorrect values correct, or should it generate
> a 0x700?

I didn't see anything in the ISA regarding incorrect values for the PTCR.
There are some build checks in the kernel though. When I have some HW, 
I will try some bogus values to see what is reported. 
 
>> +    }
>> +    env->spr[SPR_PTCR] = value;
>> +}
>> +
>> +#endif /* defined(TARGET_PPC64) */
>> +
>>  /* Segment registers load and store */
>>  target_ulong helper_load_sr(CPUPPCState *env, target_ulong sr_num)
>>  {
>> diff --git a/target/ppc/translate.c b/target/ppc/translate.c
>> index 0a0c090c9978..58684d249ed9 100644
>> --- a/target/ppc/translate.c
>> +++ b/target/ppc/translate.c
>> @@ -7131,6 +7131,9 @@ void ppc_cpu_dump_state(CPUState *cs, FILE *f, 
>> fprintf_function cpu_fprintf,
>>          if (env->spr_cb[SPR_SDR1].name) { /* SDR1 Exists */
>>              cpu_fprintf(f, " SDR1 " TARGET_FMT_lx " ", env->spr[SPR_SDR1]);
>>          }
>> +        if (env->spr_cb[SPR_PTCR].name) { /* PTCR Exists */
>> +            cpu_fprintf(f, " PTCR " TARGET_FMT_lx " ", env->spr[SPR_PTCR]);
>> +        }
>>          cpu_fprintf(f, "  DAR " TARGET_FMT_lx "  DSISR " TARGET_FMT_lx "\n",
>>                      env->spr[SPR_DAR], env->spr[SPR_DSISR]);
>>          break;
>> diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
>> index cbaa343e040d..c998ac2ee405 100644
>> --- a/target/ppc/translate_init.c
>> +++ b/target/ppc/translate_init.c
>> @@ -419,6 +419,11 @@ static void spr_write_hior(DisasContext *ctx, int sprn, 
>> int gprn)
>>      tcg_gen_st_tl(t0, cpu_env, offsetof(CPUPPCState, excp_prefix));
>>      tcg_temp_free(t0);
>>  }
>> +static void spr_write_ptcr(DisasContext *ctx, int sprn, int gprn)
>> +{
>> +    gen_helper_store_ptcr(cpu_env, cpu_gpr[gprn]);
>> +}
>> +
>>  #endif
>>  #endif
>>  
>> @@ -8166,6 +8171,18 @@ static void gen_spr_power8_rpr(CPUPPCState *env)
>>  #endif
>>  }
>>  
>> +/* Page Table */
>> +static void gen_spr_power9_ptcr(CPUPPCState *env)
> 
> Is this the only POWER9 MMU related register?  Otherwise renaming the
> function and putting them all here (eventually) would make sense.

I don't think there are any other POWER9 MMU SPRs but nevertheless,
a '_mmu' prefix has a better signification. 

Thanks,

C. 

>> +{
>> +#if !defined(CONFIG_USER_ONLY)
>> +    spr_register_hv(env, SPR_PTCR, "PTCR",
>> +                    SPR_NOACCESS, SPR_NOACCESS,
>> +                    SPR_NOACCESS, SPR_NOACCESS,
>> +                    &spr_read_generic, &spr_write_ptcr,
>> +                    0x00000000);
>> +#endif
>> +}
>> +
>>  static void init_proc_book3s_common(CPUPPCState *env)
>>  {
>>      gen_spr_ne_601(env);
>> @@ -8758,6 +8775,7 @@ static void init_proc_POWER9(CPUPPCState *env)
>>      gen_spr_power8_ic(env);
>>      gen_spr_power8_book4(env);
>>      gen_spr_power8_rpr(env);
>> +    gen_spr_power9_ptcr(env);
>>  
>>      /* POWER9 Specific registers */
>>      spr_register_kvm(env, SPR_TIDR, "TIDR", NULL, NULL,
>