Re: [Qemu-devel] [PATCH 1/1] target/ppc: Fix emulated userspace access to USPRG3

[David Gibson <david@gibson.dropbear.id.au>]

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On Thu, Apr 20, 2017 at 11:44:17AM +1000, Sam Bobroff wrote:
> On a fully emulated Power8 system, user space is currently unable to
> read from USPRG3 (SPR number 0x103) because it receives an illegal
> instruction exception.
> 
> However the ISA indicates that it should have read access (to the
> content of SPR 0x113, similar to some other registers with user space
> read-only counterparts).
> 
> This patch registers the new SPR for Book 3S processors and has it
> provide read-only access to SPR 0x113.
> 
> Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>

Heh.  I merged a more or less equivalent patch from someone else just
this morning.

> ---
>  target/ppc/translate_init.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/target/ppc/translate_init.c b/target/ppc/translate_init.c
> index c1a901455c..f863875835 100644
> --- a/target/ppc/translate_init.c
> +++ b/target/ppc/translate_init.c
> @@ -8235,6 +8235,14 @@ static void gen_spr_power8_rpr(CPUPPCState *env)
>  #endif
>  }
>  
> +static void gen_spr_book3s_usprg3(CPUPPCState *env)
> +{
> +    spr_register(env, SPR_USPRG3, "USPRG3",
> +                 &spr_read_ureg, SPR_NOACCESS,
> +                 &spr_read_ureg, SPR_NOACCESS,
> +                 0x00000000);
> +}
> +
>  static void init_proc_book3s_common(CPUPPCState *env)
>  {
>      gen_spr_ne_601(env);
> @@ -8243,6 +8251,7 @@ static void init_proc_book3s_common(CPUPPCState *env)
>      gen_spr_book3s_pmu_sup(env);
>      gen_spr_book3s_pmu_user(env);
>      gen_spr_book3s_ctrl(env);
> +    gen_spr_book3s_usprg3(env);
>  }
>  
>  static void init_proc_970(CPUPPCState *env)

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

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