target-s390: Fail on unknown instructions

We were being a bit too nice and didn't give the guest an invalid instruction
interrupt.

While that works, it's not exactly the fastest thing to do, since now the
guest doesn't know that we're not really implementing that instruction, so it
continues doing it.

We run into this with the set_page_unstable hint instruction. So let's bail out
in these cases.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index b6aac42..0992563 100644 (file)
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -405,7 +405,7 @@ static int handle_instruction(CPUState *env, struct kvm_run *run)
     unsigned int ipa0 = (run->s390_sieic.ipa & 0xff00);
     uint8_t ipa1 = run->s390_sieic.ipa & 0x00ff;
     int ipb_code = (run->s390_sieic.ipb & 0x0fff0000) >> 16;
-    int r = 0;
+    int r = -1;
 
     dprintf("handle_instruction 0x%x 0x%x\n", run->s390_sieic.ipa, run->s390_sieic.ipb);
     switch (ipa0) {