[PULL 27/33] s390x/ipl: Add PCI and bus fields to IplBlockQemuScsi

[Eric Farman <farman@linux.ibm.com>]

From: Jared Rossi <jrossi@linux.ibm.com>

Rather than add a second non-architected IPLB type for scsi-pci devices,
let's add the relevant fields to the existing struct so that it can handle
both PCI and CCW scsi controllers.

The PCI and CCW fields of the IplBlockQemuScsi are aligned with same
offsets as the corresponding fields in IplBlockPci and IplBlockCcw for
potential union access.

Add comments for PCI/CCW specifics and also denote that the S390IplType
enum values must fit in uint8_t.

Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Jared Rossi <jrossi@linux.ibm.com>
Reviewed-by: Jason J. Herne <jjherne@linux.ibm.com>
Link: https://lore.kernel.org/qemu-devel/20260831194919.3830270-5-jrossi@linux.ibm.com
Signed-off-by: Eric Farman <farman@linux.ibm.com>
---
 hw/s390x/ipl.c              |  1 +
 hw/s390x/ipl.h              |  2 ++
 include/hw/s390x/ipl/qipl.h | 13 +++++++++----
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index b2b87beefd..4fa8124f92 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -563,6 +563,7 @@ static bool s390_build_iplb(DeviceState *dev_st, IplParameterBlock *iplb)
             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_CCW;
             iplb->scsi.devno = cpu_to_be16(ccw_dev->sch->devno);
             iplb->scsi.ssid = ccw_dev->sch->ssid & 3;
             break;
diff --git a/hw/s390x/ipl.h b/hw/s390x/ipl.h
index 772566bb11..580f42aa4a 100644
--- a/hw/s390x/ipl.h
+++ b/hw/s390x/ipl.h
@@ -86,6 +86,8 @@ struct S390IPLState {
     uint16_t devno;
 };
 QEMU_BUILD_BUG_MSG(offsetof(S390IPLState, iplb) & 3, "alignment of iplb wrong");
+QEMU_BUILD_BUG_MSG(offsetof(IplBlockQemuScsi, fid) != offsetof(IplBlockPci, fid),
+                   "iplb fields misaligned across bus types");
 
 static inline bool iplb_valid_len(IplParameterBlock *iplb)
 {
diff --git a/include/hw/s390x/ipl/qipl.h b/include/hw/s390x/ipl/qipl.h
index 69b0023ea3..e733c6ce31 100644
--- a/include/hw/s390x/ipl/qipl.h
+++ b/include/hw/s390x/ipl/qipl.h
@@ -29,7 +29,7 @@ enum S390IplType {
     S390_IPL_TYPE_CCW = 0x02,
     S390_IPL_TYPE_PCI = 0x04,
     S390_IPL_TYPE_PV = 0x05,
-    S390_IPL_TYPE_QEMU_SCSI = 0xff
+    S390_IPL_TYPE_QEMU_SCSI = 0xff /* Max value, must fit in uint8_t */
 };
 typedef enum S390IplType S390IplType;
 
@@ -123,9 +123,14 @@ struct IplBlockQemuScsi {
     uint32_t lun;
     uint16_t target;
     uint16_t channel;
-    uint8_t  reserved0[77];
-    uint8_t  ssid;
-    uint16_t devno;
+    uint8_t  bus;
+    uint8_t  reserved0[76];
+    uint8_t  ssid;              /* CCW only */
+    uint16_t devno;             /* CCW only */
+    uint8_t  reserved1[216];
+    uint8_t  opt;               /* PCI only */
+    uint8_t  reserved2[3];
+    uint32_t fid;               /* PCI only */
 } QEMU_PACKED;
 typedef struct IplBlockQemuScsi IplBlockQemuScsi;
 
-- 
2.55.0