Re: [Qemu-devel] [PATCH 9/9] KVM: PPC: Enable compatibility mode

[Alexander Graf <agraf@suse.de>]

On 15.05.14 13:28, Alexey Kardashevskiy wrote:
> The host kernel implements a KVM_REG_PPC_ARCH_COMPAT register which
> this uses to enable a compatibility mode if any chosen.
>
> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> ---
>   hw/ppc/spapr.c       | 6 ++++++
>   hw/ppc/spapr_hcall.c | 4 ++++
>   target-ppc/kvm.c     | 5 +++++
>   target-ppc/kvm_ppc.h | 6 ++++++
>   4 files changed, 21 insertions(+)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index a0882a1..f89be10 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1376,6 +1376,12 @@ static void ppc_spapr_init(QEMUMachineInitArgs *args)
>           /* Tell KVM that we're in PAPR mode */
>           if (kvm_enabled()) {
>               kvmppc_set_papr(cpu);
> +
> +            if (cpu->max_compat &&
> +                kvmppc_set_compat(cpu, cpu->max_compat) < 0) {
> +                fprintf(stderr, "Unable to set compatibility mode\n");
> +                exit(1);

Why is KVM special here?

> +            }
>           }
>   
>           if (cpu->max_compat) {
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index cb815c3..2ab21d3 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -834,6 +834,10 @@ static target_ulong h_client_architecture_support(PowerPCCPU *cpu_,
>           CPU_FOREACH(cs) {
>               PowerPCCPU *cpu = POWERPC_CPU(cs);
>   
> +            if (kvmppc_set_compat(cpu, cpu_version) < 0) {
> +                fprintf(stderr, "Unable to set compatibility mode\n");
> +                return H_HARDWARE;
> +            }

Just fold this into ppc_set_compat which will run from vcpu context.


Alex

>               ppc_set_compat(cpu, cpu_version);
>           }
>       }
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index ff319fc..f8e8453 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -1513,6 +1513,11 @@ void kvmppc_set_papr(PowerPCCPU *cpu)
>       cap_papr = 1;
>   }
>   
> +int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t cpu_version)
> +{
> +    return kvm_set_one_reg(CPU(cpu), KVM_REG_PPC_ARCH_COMPAT, &cpu_version);
> +}
> +
>   void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>   {
>       CPUState *cs = CPU(cpu);
> diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h
> index ff077ec..716c33d 100644
> --- a/target-ppc/kvm_ppc.h
> +++ b/target-ppc/kvm_ppc.h
> @@ -23,6 +23,7 @@ int kvmppc_get_hasidle(CPUPPCState *env);
>   int kvmppc_get_hypercall(CPUPPCState *env, uint8_t *buf, int buf_len);
>   int kvmppc_set_interrupt(PowerPCCPU *cpu, int irq, int level);
>   void kvmppc_set_papr(PowerPCCPU *cpu);
> +int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t cpu_version);
>   void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy);
>   int kvmppc_smt_threads(void);
>   int kvmppc_clear_tsr_bits(PowerPCCPU *cpu, uint32_t tsr_bits);
> @@ -95,6 +96,11 @@ static inline void kvmppc_set_papr(PowerPCCPU *cpu)
>   {
>   }
>   
> +static inline int kvmppc_set_compat(PowerPCCPU *cpu, uint32_t cpu_version)
> +{
> +    return 0;
> +}
> +
>   static inline void kvmppc_set_mpic_proxy(PowerPCCPU *cpu, int mpic_proxy)
>   {
>   }