Re: [PATCH v3 7/8] s390x: Find scsi-pci boot device and build IPLB

[Joshua Daley <jdaley@linux.ibm.com>]

On 8/31/2026 3:49 PM, jrossi@linux.ibm.com wrote:
> From: Jared Rossi <jrossi@linux.ibm.com>
> 
> Add logic to identify a virtio-pci scsi controller and target lun with
> assigned bootindex, then build IPLB for it.
> 
> Unfence PCI case for scsi devices in BIOS.
> 
> Signed-off-by: Jared Rossi <jrossi@linux.ibm.com>
> ---
>   hw/s390x/ipl.c          | 37 +++++++++++++++++++++++++++++++++++++
>   pc-bios/s390-ccw/main.c |  3 +++
>   2 files changed, 40 insertions(+)
> 
> diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
> index 6969e11b27..0cab043b12 100644
> --- a/hw/s390x/ipl.c
> +++ b/hw/s390x/ipl.c
> @@ -402,6 +402,7 @@ static CcwDevice *s390_get_ccw_device(DeviceState *dev_st, int *devtype)
>   }
>   
>   #define PCI_DEVTYPE_VIRTIO       0x05
> +#define PCI_DEVTYPE_SCSI         0x06
>   
>   static S390PCIBusDevice *s390_get_pci_device(DeviceState *dev_st, int *devtype)
>   {
> @@ -417,6 +418,26 @@ static S390PCIBusDevice *s390_get_pci_device(DeviceState *dev_st, int *devtype)
>               if (pbdev) {
>                   tmp_dt = PCI_DEVTYPE_VIRTIO;
>               }
> +        } else {
> +            SCSIDevice *sd = (SCSIDevice *)
> +                object_dynamic_cast(OBJECT(dev_st), TYPE_SCSI_DEVICE);
> +            if (sd) {
> +                SCSIBus *sbus = scsi_bus_from_device(sd);
> +                VirtIODevice *vdev = (VirtIODevice *)
> +                    object_dynamic_cast(OBJECT(sbus->qbus.parent),
> +                                                TYPE_VIRTIO_DEVICE);
Small nit: indentation is not quite right here.
TYPE_VIRTIO_DEVICE should align with OBJECT in the line above.

> +                if (vdev) {
> +                    pci_dev = (PCIDevice *)
> +                        object_dynamic_cast(OBJECT(qdev_get_parent_bus(DEVICE(vdev))->parent),
> +                                            TYPE_PCI_DEVICE);
> +                    if (pci_dev) {
> +                        pbdev = s390_pci_find_dev_by_pci(s390_get_phb(), pci_dev);
> +                        if (pbdev) {
> +                            tmp_dt = PCI_DEVTYPE_SCSI;
> +                        }
> +                    }
> +                }
> +            }
>           }
>       }
>       if (devtype) {
> @@ -621,6 +642,22 @@ static bool s390_build_iplb(DeviceState *dev_st, IplParameterBlock *iplb)
>               iplb->pbt = S390_IPL_TYPE_PCI;
>               iplb->pci.fid = cpu_to_be32(pbdev->fid);
>               break;
> +        case PCI_DEVTYPE_SCSI:
> +            sd = SCSI_DEVICE(dev_st);
> +            scsi_lp = object_property_get_str(OBJECT(sd), "loadparm", NULL);
> +            if (scsi_lp && strlen(scsi_lp) > 0) {
> +                lp = scsi_lp;
> +            }
> +            iplb->len = cpu_to_be32(S390_IPLB_MIN_PCI_LEN);
> +            iplb->blk0_len =
> +                cpu_to_be32(S390_IPLB_MIN_PCI_LEN - S390_IPLB_HEADER_LEN);
> +            iplb->pbt = S390_IPL_TYPE_QEMU_SCSI;
> +            iplb->scsi.lun = cpu_to_be32(sd->lun);
> +            iplb->scsi.target = cpu_to_be16(sd->id);
> +            iplb->scsi.channel = cpu_to_be16(sd->channel);
> +            iplb->scsi.bus = S390_IPL_TYPE_PCI;
> +            iplb->scsi.fid = cpu_to_be32(pbdev->fid);
> +            break;
>           default:
>               return false;
>           }
> diff --git a/pc-bios/s390-ccw/main.c b/pc-bios/s390-ccw/main.c
> index a2a24b024f..d2a2ac3138 100644
> --- a/pc-bios/s390-ccw/main.c
> +++ b/pc-bios/s390-ccw/main.c
> @@ -267,6 +267,9 @@ static bool find_boot_device(void)
>               blk_schid.ssid = iplb->scsi.ssid & 0x3;
>               found = find_subch(iplb->scsi.devno);
>               break;
> +        case S390_IPL_TYPE_PCI:
> +            found = find_fid(iplb->scsi.fid);
> +            break;
>           default:
>               puts("Unrecognized SCSI controller");
>               break;