[Qemu-devel] [PATCH] target-s390x: Mask the SIGP order_code to 8bit.

[Aurelien Jarno]

From: Philipp Kern <address@hidden>

According to "CPU Signaling and Response", "Signal-Processor Orders",
the order field is bit position 56-63. Without this, the Linux
guest kernel is sometimes unable to stop emulation and enters
an infinite loop of "XXX unknown sigp: 0xffffffff00000005".

Signed-off-by: Philipp Kern <address@hidden>
Signed-off-by: Aurelien Jarno <address@hidden>
---
 target/s390x/misc_helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

This patch has been sent by Philipp Kern a lot of time ago, and it seems
has been lost. I am resending it, as it is still useful.

diff --git a/target/s390x/misc_helper.c b/target/s390x/misc_helper.c
index 3bf09ea222..4946b56ab3 100644
--- a/target/s390x/misc_helper.c
+++ b/target/s390x/misc_helper.c
@@ -534,7 +534,7 @@ uint32_t HELPER(sigp)(CPUS390XState *env, uint64_t 
order_code, uint32_t r1,
     /* Remember: Use "R1 or R1 + 1, whichever is the odd-numbered register"
        as parameter (input). Status (output) is always R1. */
 
-    switch (order_code) {
+    switch (order_code & 0xff) {
     case SIGP_SET_ARCH:
         /* switch arch */
         break;
-- 
2.11.0