Re: [Qemu-devel] [PATCH 03/17] ppc: Add a bunch of hypervisor SPRs to Book3s

[Thomas Huth]

On 14.03.2016 17:56, Cédric Le Goater wrote:
> From: Benjamin Herrenschmidt <address@hidden>
> 
> We don't give them a KVM reg number to most of the registers yet as no
> current KVM version supports HV mode. For DAWR and DAWRX, the KVM reg
> number is needed since this register can be set by the guest via the
> H_SET_MODE hypercall.
> 
> Signed-off-by: Benjamin Herrenschmidt <address@hidden>
> [clg: squashed in patch 'ppc: Add KVM numbers to some P8 SPRs' and
>       changed the commit log with a proposal of Thomas Huth ]
> Signed-off-by: Cédric Le Goater <address@hidden>
> ---
>  target-ppc/translate_init.c | 140 
> +++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 137 insertions(+), 3 deletions(-)
> 
> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
> index 6a11b41206e5..43c6e524a6bc 100644
> --- a/target-ppc/translate_init.c
> +++ b/target-ppc/translate_init.c
> @@ -1105,6 +1105,11 @@ static void gen_spr_amr (CPUPPCState *env)
>                       SPR_NOACCESS, SPR_NOACCESS,
>                       &spr_read_generic, &spr_write_generic,
>                       KVM_REG_PPC_UAMOR, 0);
> +    spr_register_hv(env, SPR_AMOR, "AMOR",
> +                    SPR_NOACCESS, SPR_NOACCESS,
> +                    SPR_NOACCESS, SPR_NOACCESS,
> +                    &spr_read_generic, &spr_write_generic,
> +                    0);
>  #endif /* !CONFIG_USER_ONLY */
>  }
>  #endif /* TARGET_PPC64 */
> @@ -7491,6 +7496,20 @@ static void gen_spr_book3s_dbg(CPUPPCState *env)
>                       KVM_REG_PPC_DABRX, 0x00000000);
>  }
>  
> +static void gen_spr_book3s_207_dbg(CPUPPCState *env)
> +{
> +    spr_register_kvm_hv(env, SPR_DAWR, "DAWR",
> +                        SPR_NOACCESS, SPR_NOACCESS,
> +                        SPR_NOACCESS, SPR_NOACCESS,
> +                        &spr_read_generic, &spr_write_generic,
> +                        KVM_REG_PPC_DAWR, 0x00000000);
> +    spr_register_kvm_hv(env, SPR_DAWRX, "DAWRX",
> +                        SPR_NOACCESS, SPR_NOACCESS,
> +                        SPR_NOACCESS, SPR_NOACCESS,
> +                        &spr_read_generic, &spr_write_generic,
> +                        KVM_REG_PPC_DAWRX, 0x00000000);
> +}
> +
>  static void gen_spr_970_dbg(CPUPPCState *env)
>  {
>      /* Breakpoints */
> @@ -7683,15 +7702,116 @@ static void gen_spr_power5p_lpar(CPUPPCState *env)
>      spr_register_kvm(env, SPR_LPCR, "LPCR",
>                       SPR_NOACCESS, SPR_NOACCESS,
>                       &spr_read_generic, &spr_write_generic,
> -                     KVM_REG_PPC_LPCR, 0x00000000);
> +                     KVM_REG_PPC_LPCR, LPCR_LPES0 | LPCR_LPES1);

Could we please postpone that hunk to a later, separate patch (after
QEMU 2.6 has been released)? It looks like it could maybe cause some
trouble with some emulated boards (e.g. there is some code in
target-ppc/excp_helper.c for example - which is currently disabled, but
I'm not sure whether there are other spots like this somewhere else).

>  }
>  
> +#if !defined(CONFIG_USER_ONLY)
> +static void spr_write_hmer(DisasContext *ctx, int sprn, int gprn)
> +{
> +    TCGv hmer = tcg_temp_new();
> +
> +    gen_load_spr(hmer, sprn);
> +    tcg_gen_and_tl(hmer, cpu_gpr[gprn], hmer);
> +    gen_store_spr(sprn, hmer);
> +    spr_store_dump_spr(sprn);
> +    tcg_temp_free(hmer);
> +}
> +#endif
> +
>  static void gen_spr_book3s_ids(CPUPPCState *env)
>  {
> +    /* FIXME: Will need to deal with thread vs core only SPRs */
> +
>      /* Processor identification */
> -    spr_register(env, SPR_PIR, "PIR",
> +    spr_register_hv(env, SPR_PIR, "PIR",
>                   SPR_NOACCESS, SPR_NOACCESS,
> -                 &spr_read_generic, &spr_write_pir,
> +                 SPR_NOACCESS, SPR_NOACCESS,
> +                 &spr_read_generic, NULL,
> +                 0x00000000);

What does the NULL mean here? I haven't seen any other spr_register*()
calls yet that pass NULL as parameter for a handler. Should that maybe
rather be a SPR_NOACCESS instead?

 Thomas