[PATCH for-8.0] target/s390x/tcg/mem_helper: Test the right bits in psw_key_valid()

[Thomas Huth <thuth@redhat.com>]

The PSW key mask is a 16 bit field, and the psw_key variable is
in the range from 0 to 15, so it does not make sense to use
"0x80 >> psw_key" for testing the bits here. We should use 0x8000
instead.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 Found by code inspection (Linux likely does not use these PSW key masks
 yet, otherwise we might have noticed earlier)

 target/s390x/tcg/mem_helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/s390x/tcg/mem_helper.c b/target/s390x/tcg/mem_helper.c
index 9542fad59b..cb82cd1c1d 100644
--- a/target/s390x/tcg/mem_helper.c
+++ b/target/s390x/tcg/mem_helper.c
@@ -51,7 +51,7 @@ static inline bool psw_key_valid(CPUS390XState *env, uint8_t psw_key)
 
     if (env->psw.mask & PSW_MASK_PSTATE) {
         /* PSW key has range 0..15, it is valid if the bit is 1 in the PKM */
-        return pkm & (0x80 >> psw_key);
+        return pkm & (0x8000 >> psw_key);
     }
     return true;
 }
-- 
2.31.1