Re: [PATCH 09/15] s390x: protvirt: SCLP interpretation

[Cornelia Huck]

On Wed, 20 Nov 2019 06:43:28 -0500
Janosch Frank <address@hidden> wrote:

> SCLP for a protected guest is done over the SIDAD, so we need to use
> the s390_cpu_virt_mem_* functions to access the SIDAD instead of guest
> memory when reading/writing SCBs.
> 
> To not confuse the sclp emulation, we set 0x42000 as the address, but
> ignore it for reading/writing the SCCB.
> 
> Signed-off-by: Janosch Frank <address@hidden>
> ---
>  hw/s390x/sclp.c         | 16 ++++++++++++++++
>  include/hw/s390x/sclp.h |  2 ++
>  target/s390x/kvm.c      |  8 +++++++-
>  3 files changed, 25 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
> index f57ce7b739..00d08adc7f 100644
> --- a/hw/s390x/sclp.c
> +++ b/hw/s390x/sclp.c
> @@ -193,6 +193,22 @@ static void sclp_execute(SCLPDevice *sclp, SCCB *sccb, 
> uint32_t code)
>      }
>  }
>  
> +int sclp_service_call_protected(CPUS390XState *env, uint64_t sccb,
> +                                uint32_t code)
> +{
> +    SCLPDevice *sclp = get_sclp_device();
> +    SCLPDeviceClass *sclp_c = SCLP_GET_CLASS(sclp);
> +    SCCB work_sccb;
> +    hwaddr sccb_len = sizeof(SCCB);
> +
> +    s390_cpu_virt_mem_read(env_archcpu(env), 0, 0, &work_sccb, sccb_len);
> +    sclp_c->execute(sclp, &work_sccb, code);
> +    s390_cpu_virt_mem_write(env_archcpu(env), 0, 0, &work_sccb,
> +                            be16_to_cpu(work_sccb.h.length));
> +    sclp_c->service_interrupt(sclp, sccb);
> +    return 0;
> +}
> +
>  int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code)
>  {
>      SCLPDevice *sclp = get_sclp_device();
> diff --git a/include/hw/s390x/sclp.h b/include/hw/s390x/sclp.h
> index c54413b78c..c0a3faa37d 100644
> --- a/include/hw/s390x/sclp.h
> +++ b/include/hw/s390x/sclp.h
> @@ -217,5 +217,7 @@ void s390_sclp_init(void);
>  void sclp_service_interrupt(uint32_t sccb);
>  void raise_irq_cpu_hotplug(void);
>  int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code);
> +int sclp_service_call_protected(CPUS390XState *env, uint64_t sccb,
> +                                uint32_t code);
>  
>  #endif
> diff --git a/target/s390x/kvm.c b/target/s390x/kvm.c
> index 58251c0229..0f2458b553 100644
> --- a/target/s390x/kvm.c
> +++ b/target/s390x/kvm.c
> @@ -1172,7 +1172,13 @@ static int kvm_sclp_service_call(S390CPU *cpu, struct 
> kvm_run *run,
>      sccb = env->regs[ipbh0 & 0xf];
>      code = env->regs[(ipbh0 & 0xf0) >> 4];
>  
> -    r = sclp_service_call(env, sccb, code);
> +    if (run->s390_sieic.icptcode == ICPT_PV_INSTR ||
> +        run->s390_sieic.icptcode == ICPT_PV_INSTR_NOT) {
> +        r = sclp_service_call_protected(env, 0x42000, code);

I fear that confuses the reader instead of the emulation :)

Especially as you end up passing that value to
sclp_c->service_interrupt()...

> +    } else {
> +        r = sclp_service_call(env, sccb, code);
> +    }
> +
>      if (r < 0) {
>          kvm_s390_program_interrupt(cpu, -r);
>      } else {