Re: [Qemu-ppc] [PATCH v3 14/15] spapr/irq: initialize the IRQ device only once

[David Gibson]

On Thu, Mar 21, 2019 at 03:49:13PM +0100, Cédric Le Goater wrote:
> Add a check to make sure that the routine initializing the emulated
> IRQ device is called once. We don't have much to test on the XICS
> side, so we introduce a 'static bool'. Not very elegant but works well
> enough.

What's the rationale for this?

> 
> Signed-off-by: Cédric Le Goater <address@hidden>
> ---
>  hw/intc/spapr_xive.c |  9 +++++++++
>  hw/intc/xics_spapr.c | 10 ++++++++++
>  2 files changed, 19 insertions(+)
> 
> diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
> index f889c89dc2e9..15d41d9cd36d 100644
> --- a/hw/intc/spapr_xive.c
> +++ b/hw/intc/spapr_xive.c
> @@ -337,6 +337,15 @@ void spapr_xive_init(SpaprXive *xive, Error **errp)
>      XiveSource *xsrc = &xive->source;
>      XiveENDSource *end_xsrc = &xive->end_source;
>  
> +    /*
> +     * The emulated XIVE device can only be initialized once. If the
> +     * ESB memory region has been already mapped, it means we have been
> +     * through there.
> +     */
> +    if (memory_region_is_mapped(&xsrc->esb_mmio)) {
> +        return;
> +    }
> +
>      /* TIMA initialization */
>      memory_region_init_io(&xive->tm_mmio, OBJECT(xive), &xive_tm_ops, xive,
>                            "xive.tima", 4ull << TM_SHIFT);
> diff --git a/hw/intc/xics_spapr.c b/hw/intc/xics_spapr.c
> index 9d2b8adef7c5..67e82f3720b0 100644
> --- a/hw/intc/xics_spapr.c
> +++ b/hw/intc/xics_spapr.c
> @@ -239,6 +239,16 @@ static void rtas_int_on(PowerPCCPU *cpu, 
> SpaprMachineState *spapr,
>  
>  void xics_spapr_init(SpaprMachineState *spapr)
>  {
> +    static bool init_done;
> +
> +    /*
> +     * Emulated mode can only be initialized once.
> +     */
> +    if (init_done) {
> +        return;
> +    }
> +    init_done = true;
> +
>      /* Registration of global state belongs into realize */
>      spapr_rtas_register(RTAS_IBM_SET_XIVE, "ibm,set-xive", rtas_set_xive);
>      spapr_rtas_register(RTAS_IBM_GET_XIVE, "ibm,get-xive", rtas_get_xive);

-- 
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

signature.asc
Description: PGP signature