Migrate rtc_ref (which only needs to be 32-bit because it is summed to
a 32-bit register), which requires bumping the migration version.
The HPPA machine does not have versioned machine types so it is okay
to block migration to old versions of QEMU.

While at it, drop the write-only field rtc from LasiState.

Supersedes: <20230330120319.36069-1-pbonzini@redhat.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/misc/lasi.c         | 4 ++--
 include/hw/misc/lasi.h | 3 +--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/hw/misc/lasi.c b/hw/misc/lasi.c
index 23a7634a8c3a..ff9dc893ae65 100644
--- a/hw/misc/lasi.c
+++ b/hw/misc/lasi.c
@@ -194,7 +194,7 @@ static const MemoryRegionOps lasi_chip_ops = {
 
 static const VMStateDescription vmstate_lasi = {
     .name = "Lasi",
-    .version_id = 1,
+    .version_id = 2,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(irr, LasiState),
@@ -204,6 +204,7 @@ static const VMStateDescription vmstate_lasi = {
         VMSTATE_UINT32(iar, LasiState),
         VMSTATE_UINT32(errlog, LasiState),
         VMSTATE_UINT32(amr, LasiState),
+        VMSTATE_UINT32_V(rtc_ref, LasiState, 2),
         VMSTATE_END_OF_LIST()
     }
 };
@@ -233,7 +234,6 @@ static void lasi_reset(DeviceState *dev)
     s->iar = 0xFFFB0000 + 3; /* CPU_HPA + 3 */
 
     /* Real time clock (RTC), it's only one 32-bit counter @9000 */
-    s->rtc = time(NULL);
     s->rtc_ref = 0;
 }
 
diff --git a/include/hw/misc/lasi.h b/include/hw/misc/lasi.h
index ecc7065ce858..0a8c7352be21 100644
--- a/include/hw/misc/lasi.h
+++ b/include/hw/misc/lasi.h
@@ -69,8 +69,7 @@ struct LasiState {
 
     uint32_t errlog;
     uint32_t amr;
-    uint32_t rtc;
-    time_t rtc_ref;
+    uint32_t rtc_ref;
 
     MemoryRegion this_mem;
 };
-- 
2.39.2