Right now, the system reset is concluded by a call to
cpu_synchronize_all_post_reset() in order to sync any changes
that the machine reset callback applied to the CPU state.
However, for VMs with encrypted state such as SEV-ES guests (currently
the only case of guests with non-resettable CPUs) this cannot be done,
because guest state has already been finalized by machine-init-done notifiers.
cpu_synchronize_all_post_reset() does nothing on these guests, and actually
we would like to make it fail if called once guest has been encrypted.
So, assume that boards that support non-resettable CPUs do not touch
CPU state and that all such setup is done before, at the time of
cpu_synchronize_all_post_init().
Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
system/runstate.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/system/runstate.c b/system/runstate.c
index d6ab860ecaa..cb4905a40fc 100644
--- a/system/runstate.c
+++ b/system/runstate.c
@@ -501,7 +501,20 @@ void qemu_system_reset(ShutdownCause reason)
default:
qapi_event_send_reset(shutdown_caused_by_guest(reason), reason);
}
- cpu_synchronize_all_post_reset();
+
+ /*
+ * Some boards use the machine reset callback to point CPUs to the firmware
+ * entry point. Assume that this is not the case for boards that support
+ * non-resettable CPUs (currently used only for confidential guests), in
+ * which case cpu_synchronize_all_post_init() is enough because
+ * it does _more_ than cpu_synchronize_all_post_reset().
+ */
+ if (cpus_are_resettable()) {
+ cpu_synchronize_all_post_reset();
+ } else {
+ assert(runstate_check(RUN_STATE_PRELAUNCH));
+ }
+
vm_set_suspended(false);
}
--
2.44.0
