[PATCH] target/s390x: Make container ids in SysIB_15x 1-based

[Alexandra Winter <wintera@linux.ibm.com>]

The Container Id in a container-type TLE of SysIB_15x is defined as 8-bit
unsigned nonzero integer. Make stsi fc 15 emulation architecture compliant,
by starting the container ids at 1 for the lowest numbered container.

The qemu misbehaviour without this patch becomes obvious due to a recently
proposed kernel fix. Older linux kernels pass the container ids from stsi
fc15 unchanged to sysfs, i.e. starting at 1 on s390 hardware. This resulted
in off-by-one values when compared to the values from HMC. A Linux kernel
fix is being proposed to correct the sysfs topology ids by -1, so they
start at 0, e.g. when displayed by 'lscpu -ye'. In case a KVM guest with a
fixed kernel runs on a host with a qemu without this fix, this can result
in container ids erroneously being shown as 255.
Example (Fixed guest on unfixed qemu):
$ lscpu -ye
CPU NODE DRAWER BOOK SOCKET CORE L1d:L1i:L2 ONLINE CONFIGURED POLARIZATION ADDRESS
  0    0    255  255    255    0 0:0:0         yes yes        vert-medium  0
  1    0    255  255      0    1 1:1:1         yes yes        vert-medium  1
After this fix:
$ lscpu -ye
CPU NODE DRAWER BOOK SOCKET CORE L1d:L1i:L2 ONLINE CONFIGURED POLARIZATION ADDRESS
  0    0      0    0      0    0 0:0:0         yes yes        vert-medium  0
  1    0      0    0      1    1 1:1:1         yes yes        vert-medium  1

Fixes: f4f54b582f ("target/s390x/cpu topology: handle STSI(15) and build the SYSIB")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
---
 target/s390x/kvm/stsi-topology.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/target/s390x/kvm/stsi-topology.c b/target/s390x/kvm/stsi-topology.c
index 301d41b68d..afd00da0e6 100644
--- a/target/s390x/kvm/stsi-topology.c
+++ b/target/s390x/kvm/stsi-topology.c
@@ -90,9 +90,9 @@ static int stsi_topology_fill_sysib(S390TopologyList *topology_list,
     int last_drawer = -1;
     int last_book = -1;
     int last_socket = -1;
-    int drawer_id = 0;
-    int book_id = 0;
-    int socket_id = 0;
+    int drawer_id = 1;
+    int book_id = 1;
+    int socket_id = 1;
     int n = sizeof(SysIB_151x);
 
     QTAILQ_FOREACH(entry, topology_list, next) {
@@ -103,12 +103,12 @@ static int stsi_topology_fill_sysib(S390TopologyList *topology_list,
         if (level > 3 && drawer_change) {
             SYSIB_GUARD(n, sizeof(SYSIBContainerListEntry));
             p = fill_container(p, 3, drawer_id++);
-            book_id = 0;
+            book_id = 1;
         }
         if (level > 2 && book_change) {
             SYSIB_GUARD(n, sizeof(SYSIBContainerListEntry));
             p = fill_container(p, 2, book_id++);
-            socket_id = 0;
+            socket_id = 1;
         }
         if (socket_change) {
             SYSIB_GUARD(n, sizeof(SYSIBContainerListEntry));
-- 
2.39.5 (Apple Git-154)