Re: [Qemu-devel] [PULL 09/20] s390x/ipl: Remove redundant usage of gr7

[Paolo Bonzini]

On 17/05/2016 16:46, Cornelia Huck wrote:
> From: Alexander Yarygin <address@hidden>
> 
> We don't need to pass device address for pc-bios using gr7 anymore as
> the pcbios completely relies on diag308 now, so we can remove it from
> qemu. devno, ssid and cssid are migrated but the value was never reused,
> so we can safely ignore these fields and migrate 0.
> 
> Signed-off-by: Alexander Yarygin <address@hidden>
> Reviewed-by: David Hildenbrand <address@hidden>
> Signed-off-by: Cornelia Huck <address@hidden>

This probably breaks reboot after migration from 2.6.

If that's fine, all the better. :)

Thanks,

Paolo

> ---
>  hw/s390x/ipl.c | 33 ++++++---------------------------
>  1 file changed, 6 insertions(+), 27 deletions(-)
> 
> diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
> index 2da0f1e..5786b5e 100644
> --- a/hw/s390x/ipl.c
> +++ b/hw/s390x/ipl.c
> @@ -208,50 +208,27 @@ static Property s390_ipl_properties[] = {
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> -/*
> - * In addition to updating the iplstate, this function returns:
> - * - 0 if system was ipled with external kernel
> - * - -1 if no valid boot device was found
> - * - ccw id of the boot device otherwise
> - */
> -static uint64_t s390_update_iplstate(S390IPLState *ipl)
> +static bool s390_gen_initial_iplb(S390IPLState *ipl)
>  {
>      DeviceState *dev_st;
>  
> -    if (ipl->iplb_valid) {
> -        ipl->cssid = 0;
> -        ipl->ssid = 0;
> -        ipl->devno = ipl->iplb.devno;
> -        goto out;
> -    }
> -
> -    if (ipl->kernel) {
> -        return 0;
> -    }
> -
>      dev_st = get_boot_device(0);
>      if (dev_st) {
>          VirtioCcwDevice *ccw_dev = (VirtioCcwDevice *) object_dynamic_cast(
>              OBJECT(qdev_get_parent_bus(dev_st)->parent),
>                  TYPE_VIRTIO_CCW_DEVICE);
>          if (ccw_dev) {
> -            ipl->cssid = ccw_dev->sch->cssid;
> -            ipl->ssid = ccw_dev->sch->ssid;
> -            ipl->devno = ccw_dev->sch->devno;
>              ipl->iplb.len = cpu_to_be32(S390_IPLB_MIN_CCW_LEN);
>              ipl->iplb.blk0_len =
>                  cpu_to_be32(S390_IPLB_MIN_CCW_LEN - S390_IPLB_HEADER_LEN);
>              ipl->iplb.pbt = S390_IPL_TYPE_CCW;
>              ipl->iplb.ccw.devno = cpu_to_be16(ccw_dev->sch->devno);
>              ipl->iplb.ccw.ssid = ccw_dev->sch->ssid & 3;
> -            ipl->iplb_valid = true;
> -            goto out;
> +            return true;
>          }
>      }
>  
> -    return -1;
> -out:
> -    return (uint32_t) (ipl->cssid << 24 | ipl->ssid << 16 | ipl->devno);
> +    return false;
>  }
>  
>  void s390_ipl_update_diag308(IplParameterBlock *iplb)
> @@ -289,7 +266,9 @@ void s390_ipl_prepare_cpu(S390CPU *cpu)
>  
>      if (!ipl->kernel || ipl->iplb_valid) {
>          cpu->env.psw.addr = ipl->bios_start_addr;
> -        cpu->env.regs[7] = s390_update_iplstate(ipl);
> +        if (!ipl->iplb_valid) {
> +            ipl->iplb_valid = s390_gen_initial_iplb(ipl);
> +        }
>      }
>  }
>  
>