[PATCH for 11.0 1/2] runstate: handle return code of EOPNOTSUPP properly from rebuild_guest()

[Ani Sinha]

If rebuild_guest() accelerator callback returns EOPNOTSUPP, this means that the
accelerator does not support rebuilding the guest state. Handle this case
properly and separately from other error return codes.

Fixes: 4003e5e65fe0("hw/accel: add a per-accelerator callback to change VM 
accelerator handle")
Reported-by: Harsh Prateek Bora <hars...@linux.ibm.com>
Signed-off-by: Ani Sinha <anisi...@redhat.com>
---
 system/runstate.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/system/runstate.c b/system/runstate.c
index eca722b43c..c1f41284c9 100644
--- a/system/runstate.c
+++ b/system/runstate.c
@@ -531,10 +531,12 @@ void qemu_system_reset(ShutdownCause reason)
         (current_machine->new_accel_vmfd_on_reset || !cpus_are_resettable())) {
         if (ac->rebuild_guest) {
             ret = ac->rebuild_guest(current_machine);
-            if (ret < 0) {
+            if (ret < 0 && ret != -EOPNOTSUPP) {
                 error_report("unable to rebuild guest: %s(%d)",
                              strerror(-ret), ret);
                 vm_stop(RUN_STATE_INTERNAL_ERROR);
+            } else if (ret == -EOPNOTSUPP) {
+                error_report("accelerator does not support reset!");
             } else {
                 info_report("virtual machine state has been rebuilt with new "
                             "guest file handle.");
-- 
2.42.0