spapr: Use SHUTDOWN_CAUSE_SUBSYSTEM_RESET for CAS reboots

The sPAPR platform includes feature negotiation between the guest and
platform.  That sometimes requires reconfiguring the virtual hardware, and
in some cases that is a complex enough process that we trigger a system
reset to handle it.  That interacts badly with -no-reboot - we trigger the
reboot, -no-reboot means we exit and so the guest never gets to try again.

Eventually we want to get rid of CAS reboots entirely, since they're odd
and irritating for the user.  But in the meantime we can fix the -no-reboot
problem by using SHUTDOWN_CAUSE_SUBSYSTEM_RESET which ignores -no-reboot
and seems to be designed for this sort of faux-reset for internal purposes
only.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index e20a946b99b4e24bd0487fd2f76b76e8810131f9..23e4bdb829c56671cf5e3755ac3a991de2e35a3b 100644 (file)
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -1811,7 +1811,7 @@ static target_ulong h_client_architecture_support(PowerPCCPU *cpu,
     spapr_ovec_cleanup(ov5_updates);
 
     if (spapr->cas_reboot) {
-        qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
+        qemu_system_reset_request(SHUTDOWN_CAUSE_SUBSYSTEM_RESET);
     }
 
     return H_SUCCESS;