[Qemu-devel] Re: [PATCH] PPC: Get MMU state on register sync

[Jan Kiszka]

Alexander Graf wrote:
> While x86 only needs to sync cr0-4 to know all about its MMU state and enable
> qemu to resolve virtual to physical addresses, we need to sync all of the
> segment registers on PPC to know which mapping we're in.
> 
> So let's grab the segment register contents to be able to use the "x" monitor
> command and also enable the gdbstub to resolve virtual addresses.
> 
> I sent the corresponding KVM patch to the KVM ML some minutes ago.
> 
> Signed-off-by: Alexander Graf <address@hidden>
> ---
>  target-ppc/kvm.c |   30 ++++++++++++++++++++++++++++++
>  1 files changed, 30 insertions(+), 0 deletions(-)
> 
> diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> index 4e1c65f..566513f 100644
> --- a/target-ppc/kvm.c
> +++ b/target-ppc/kvm.c
> @@ -98,12 +98,17 @@ int kvm_arch_put_registers(CPUState *env)
>  int kvm_arch_get_registers(CPUState *env)
>  {
>      struct kvm_regs regs;
> +    struct kvm_sregs sregs;
>      uint32_t i, ret;
>  
>      ret = kvm_vcpu_ioctl(env, KVM_GET_REGS, &regs);
>      if (ret < 0)
>          return ret;
>  
> +    ret = kvm_vcpu_ioctl(env, KVM_GET_SREGS, &sregs);
> +    if (ret < 0)
> +        return ret;
> +
>      env->ctr = regs.ctr;
>      env->lr = regs.lr;
>      env->xer = regs.xer;
> @@ -125,6 +130,31 @@ int kvm_arch_get_registers(CPUState *env)
>      for (i = 0;i < 32; i++)
>          env->gpr[i] = regs.gpr[i];
>  
> +#ifdef KVM_CAP_PPC_SEGSTATE
> +    if (kvm_check_extension(env->kvm_state, KVM_CAP_PPC_SEGSTATE)) {
> +        env->sdr1 = sregs.sdr1;
> +    
> +        /* Sync SLB */
> +        for (i = 0; i < 64; i++) {
> +            ppc_store_slb(env, sregs.ppc64.slb[i].slbe,
> +                               sregs.ppc64.slb[i].slbv);
> +        }
> +    
> +        /* Sync SRs */
> +        for (i = 0; i < 16; i++) {
> +            env->sr[i] = sregs.ppc32.sr[i];
> +        }
> +    
> +        /* Sync BATs */
> +        for (i = 0; i < 8; i++) {
> +            env->DBAT[0][i] = sregs.ppc32.dbat[i] & 0xffffffff;
> +            env->DBAT[1][i] = sregs.ppc32.dbat[i] >> 32;
> +            env->IBAT[0][i] = sregs.ppc32.ibat[i] & 0xffffffff;
> +            env->IBAT[1][i] = sregs.ppc32.ibat[i] >> 32;
> +        }
> +    }
> +#endif
> +
>      return 0;
>  }
>  

What about KVM_SET_SREGS in kvm_arch_put_registers? E.g. to play back
potential changes to that special registers someone did via gdb?

Jan

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