Re: [Qemu-devel] [PATCH 02/10] ppc: Create cpu_ppc_set_papr() helper (for LPCR)

[David Gibson]

On Mon, Jun 13, 2016 at 07:24:48AM +0200, Cédric Le Goater wrote:
> From: Benjamin Herrenschmidt <address@hidden>
> 
> And move the code adjusting the MSR mask and calling kvmppc_set_papr()
> to it. This allows us to add a few more things such as disabling setting
> of MSR:HV and appropriate LPCR bits which will be used when fixing
> the exception model.
> 
> Signed-off-by: Benjamin Herrenschmidt <address@hidden>
> Reviewed-by: David Gibson <address@hidden>
> [clg: previous commit 26a7f1291bb5 did not include the LPCR setting as
>       it was not needed at the time ]

I see how this came about, but it means the commit message (both long
and short) is confusingly mismatched from the code now.

> Signed-off-by: Cédric Le Goater <address@hidden>
> ---
>  target-ppc/translate_init.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
> 
> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
> index ca894ff4af45..edfd91a85425 100644
> --- a/target-ppc/translate_init.c
> +++ b/target-ppc/translate_init.c
> @@ -8509,6 +8509,7 @@ POWERPC_FAMILY(POWER8)(ObjectClass *oc, void *data)
>  void cpu_ppc_set_papr(PowerPCCPU *cpu)
>  {
>      CPUPPCState *env = &cpu->env;
> +    ppc_spr_t *lpcr = &env->spr_cb[SPR_LPCR];
>      ppc_spr_t *amor = &env->spr_cb[SPR_AMOR];
>  
>      /* PAPR always has exception vectors in RAM not ROM. To ensure this,
> @@ -8518,6 +8519,19 @@ void cpu_ppc_set_papr(PowerPCCPU *cpu)
>       */
>      env->msr_mask &= ~((1ull << MSR_EP) | MSR_HVB);
>  
> +    /* Set emulated LPCR to not send interrupts to hypervisor. Note that
> +     * under KVM, the actual HW LPCR will be set differently by KVM itself,
> +     * the settings below ensure proper operations with TCG in absence of
> +     * a real hypervisor
> +     */
> +    lpcr->default_value &= ~(LPCR_VPM0 | LPCR_VPM1 | LPCR_ISL | LPCR_KBV);
> +    lpcr->default_value |= LPCR_LPES0 | LPCR_LPES1;
> +
> +    /* We should be followed by a CPU reset but update the active value
> +     * just in case...
> +     */
> +    env->spr[SPR_LPCR] = lpcr->default_value;
> +
>      /* Set a full AMOR so guest can use the AMR as it sees fit */
>      env->spr[SPR_AMOR] = amor->default_value = 0xffffffffffffffffull;
>  

-- 
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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