Re: [Qemu-devel] [PATCH 1/4] spapr: only update SDR1 once per-cpu during CAS

[David Gibson]

On Mon, Sep 04, 2017 at 11:46:55PM +0200, Greg Kurz wrote:
> Commit b55d295e3ec9 added the possibility to support HPT resizing with KVM.
> In the case of PR, we need to pass the userspace address of the HPT to KVM
> using the SDR1 slot.
> This is handled by kvmppc_update_sdr1() which uses CPU_FOREACH() to update
> all CPUs. It is hence not needed to call kvmppc_update_sdr1() for each CPU.
> 
> Signed-off-by: Greg Kurz <address@hidden>

Applied to ppc-for-2.11.

> ---
>  hw/ppc/spapr_hcall.c |   14 +++++---------
>  1 file changed, 5 insertions(+), 9 deletions(-)
> 
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 8b3c0e17e75c..6ab8c188f381 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -1559,20 +1559,16 @@ static target_ulong 
> h_client_architecture_support(PowerPCCPU *cpu,
>          }
>  
>          if (spapr->htab_shift < maxshift) {
> -            CPUState *cs;
> -
>              /* Guest doesn't know about HPT resizing, so we
>               * pre-emptively resize for the maximum permitted RAM.  At
>               * the point this is called, nothing should have been
>               * entered into the existing HPT */
>              spapr_reallocate_hpt(spapr, maxshift, &error_fatal);
> -            CPU_FOREACH(cs) {
> -                if (kvm_enabled()) {
> -                    /* For KVM PR, update the HPT pointer */
> -                    target_ulong sdr1 = (target_ulong)(uintptr_t)spapr->htab
> -                        | (spapr->htab_shift - 18);
> -                    kvmppc_update_sdr1(sdr1);
> -                }
> +            if (kvm_enabled()) {
> +                /* For KVM PR, update the HPT pointer */
> +                target_ulong sdr1 = (target_ulong)(uintptr_t)spapr->htab
> +                    | (spapr->htab_shift - 18);
> +                kvmppc_update_sdr1(sdr1);
>              }
>          }
>      }
> 

-- 
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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