On Tue, Jun 07, 2016 at 05:39:39PM +0200, Thomas Huth wrote: > When using an olderr PowerISA level, all the upper compatibility > bits have to be enabled, too. For example when we want to run > something in PowerISA 2.05 compatibility mode on POWER8, the bit > for 2.06 has to be set beside the bit for 2.05. > Additionally, to make sure that we do not set bits that are not > supported by the host, we apply a mask with the known-to-be-good > bits here, too. > > Signed-off-by: Thomas Huth <th...@redhat.com>
This one confused me a bit until I realised that, roughly speaking,
bits in the PCR turn features off, rather than turning features on.
Does that sound correct?
> ---
> target-ppc/translate_init.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/target-ppc/translate_init.c b/target-ppc/translate_init.c
> index fa09183..ee2bc14 100644
> --- a/target-ppc/translate_init.c
> +++ b/target-ppc/translate_init.c
> @@ -9519,24 +9519,29 @@ void ppc_set_compat(PowerPCCPU *cpu, uint32_t
> cpu_version, Error **errp)
> {
> int ret = 0;
> CPUPPCState *env = &cpu->env;
> + PowerPCCPUClass *host_pcc;
>
> cpu->cpu_version = cpu_version;
>
> switch (cpu_version) {
> case CPU_POWERPC_LOGICAL_2_05:
> - env->spr[SPR_PCR] = PCR_COMPAT_2_05;
> + env->spr[SPR_PCR] = PCR_TM_DIS | PCR_VSX_DIS | PCR_COMPAT_2_07 |
> + PCR_COMPAT_2_06 | PCR_COMPAT_2_05;
> break;
> case CPU_POWERPC_LOGICAL_2_06:
> - env->spr[SPR_PCR] = PCR_COMPAT_2_06;
> - break;
> case CPU_POWERPC_LOGICAL_2_06_PLUS:
> - env->spr[SPR_PCR] = PCR_COMPAT_2_06;
> + env->spr[SPR_PCR] = PCR_TM_DIS | PCR_COMPAT_2_07 | PCR_COMPAT_2_06;
> break;
> default:
> env->spr[SPR_PCR] = 0;
> break;
> }
>
> + host_pcc = kvm_ppc_get_host_cpu_class();
> + if (host_pcc) {
> + env->spr[SPR_PCR] &= host_pcc->pcr_mask;
> + }
> +
> if (kvm_enabled()) {
> ret = kvmppc_set_compat(cpu, cpu->cpu_version);
> if (ret < 0) {
--
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
