[PULL 18/43] hw/s390x/css: drop use of .err_hint for vmstate

[Fabiano Rosas <farosas@suse.de>]

From: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>

That's the only usage through the whole base. Doesn't
worth keeping the whole complexity. And 2.7 machines were
long ago.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20260304212303.667141-17-vsementsov@yandex-team.ru
Signed-off-by: Fabiano Rosas <farosas@suse.de>
---
 hw/s390x/css.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 04ce3178a0..df5f0bc27f 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -192,10 +192,6 @@ static const VMStateDescription vmstate_schdev_orb = {
 static int subch_dev_post_load(void *opaque, int version_id);
 static int subch_dev_pre_save(void *opaque);
 
-const char err_hint_devno[] = "Devno mismatch, tried to load wrong section!"
-    " Likely reason: some sequences of plug and unplug  can break"
-    " migration for machine versions prior to  2.7 (known design flaw).";
-
 const VMStateDescription vmstate_subch_dev = {
     .name = "s390_subch_dev",
     .version_id = 1,
@@ -203,10 +199,15 @@ const VMStateDescription vmstate_subch_dev = {
     .post_load = subch_dev_post_load,
     .pre_save = subch_dev_pre_save,
     .fields = (const VMStateField[]) {
-        VMSTATE_UINT8_EQUAL(cssid, SubchDev, "Bug!"),
-        VMSTATE_UINT8_EQUAL(ssid, SubchDev, "Bug!"),
+        VMSTATE_UINT8_EQUAL(cssid, SubchDev, NULL),
+        VMSTATE_UINT8_EQUAL(ssid, SubchDev, NULL),
         VMSTATE_UINT16(migrated_schid, SubchDev),
-        VMSTATE_UINT16_EQUAL(devno, SubchDev, err_hint_devno),
+        /*
+         * If devno mismatch on target, it may be due to some
+         * sequences of plug and unplug breaks migration for
+         * machine versions prior to 2.7 (known design flaw).
+         */
+        VMSTATE_UINT16_EQUAL(devno, SubchDev, NULL),
         VMSTATE_BOOL(thinint_active, SubchDev),
         VMSTATE_STRUCT(curr_status, SubchDev, 0, vmstate_schib, SCHIB),
         VMSTATE_UINT8_ARRAY(sense_data, SubchDev, 32),
-- 
2.51.0