[Qemu-ppc] [PATCH 3/4] spapr: Make ibm, change-msi respect 3 return values

[Sam Bobroff]

Currently, rtas_ibm_change_msi() always returns four values even if
less are specified.

Correct this by only returning the fourth parameter if it was
requested.

This is specified by PAPR.

Signed-off-by: Sam Bobroff <address@hidden>
---
 hw/ppc/spapr_pci.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 05f4fac..f422e3b 100644
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -360,7 +360,9 @@ out:
     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
     rtas_st(rets, 1, req_num);
     rtas_st(rets, 2, ++seq_num);
-    rtas_st(rets, 3, ret_intr_type);
+    if (nret > 3) {
+        rtas_st(rets, 3, ret_intr_type);
+    }
 
     trace_spapr_pci_rtas_ibm_change_msi(config_addr, func, req_num, irq);
 }
-- 
2.1.4