Re: [Qemu-devel] [PATCHv3 3/4] pseries: Reset CPU compatibility mode

[Michael Roth]

Quoting David Gibson (2017-04-27 02:28:42)
> Currently, the CPU compatibility mode is set when the cpu is initialized,
> then again when the guest negotiates features.  This means if a guest
> negotiates a compatibility mode, then reboots, that compatibility mode
> will be retained across the reset.
> 
> Usually that will get overridden when features are negotiated on the next
> boot, but it's still not really correct.  This patch moves the initial set
> up of the compatibility mode from cpu init to reset time.  The mode *is*
> retained if the reboot was caused by the feature negotiation (it might
> be important in that case, though it's unlikely).
> 
> Signed-off-by: David Gibson <address@hidden>
> Reviewed-by: Alexey Kardashevskiy <address@hidden>

Reviewed-by: Michael Roth <address@hidden>

> ---
>  hw/ppc/spapr.c          |  2 ++
>  hw/ppc/spapr_cpu_core.c | 10 ----------
>  2 files changed, 2 insertions(+), 10 deletions(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 547fa27..67f5106 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1332,6 +1332,8 @@ static void ppc_spapr_reset(void)
>      if (!spapr->cas_reboot) {
>          spapr_ovec_cleanup(spapr->ov5_cas);
>          spapr->ov5_cas = spapr_ovec_new();
> +
> +        ppc_set_compat_all(spapr->max_compat_pvr, &error_abort);
>      }
> 
>      fdt = spapr_build_fdt(spapr, rtas_addr, spapr->rtas_size);
> diff --git a/hw/ppc/spapr_cpu_core.c b/hw/ppc/spapr_cpu_core.c
> index ba610bc..e810431 100644
> --- a/hw/ppc/spapr_cpu_core.c
> +++ b/hw/ppc/spapr_cpu_core.c
> @@ -107,16 +107,6 @@ static void spapr_cpu_init(sPAPRMachineState *spapr, 
> PowerPCCPU *cpu,
>      /* Enable PAPR mode in TCG or KVM */
>      cpu_ppc_set_papr(cpu, PPC_VIRTUAL_HYPERVISOR(spapr));
> 
> -    if (spapr->max_compat_pvr) {
> -        Error *local_err = NULL;
> -
> -        ppc_set_compat(cpu, spapr->max_compat_pvr, &local_err);
> -        if (local_err) {
> -            error_propagate(errp, local_err);
> -            return;
> -        }
> -    }
> -
>      qemu_register_reset(spapr_cpu_reset, cpu);
>      spapr_cpu_reset(cpu);
>  }
> -- 
> 2.9.3
>