selftests: KVM: s390: fix early guest crash

The guest crashes very early due to changes in the control registers
used by dynamic address translation. Let us use different registers
that will not crash the guest.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/tools/testing/selftests/kvm/s390x/resets.c b/tools/testing/selftests/kvm/s390x/resets.c
index bf04d77de16b52d4eba50cbd6e1fa019f62707df..83624d0b1453b8678995a0a71ee69f1ea4c7a363 100644 (file)
--- a/tools/testing/selftests/kvm/s390x/resets.c
+++ b/tools/testing/selftests/kvm/s390x/resets.c
@@ -23,25 +23,24 @@ struct kvm_run *run;
 struct kvm_sync_regs *regs;
 static uint64_t regs_null[16];
 
-static uint64_t crs[16] = { 0x40000ULL,
-                           0x42000ULL,
-                           0, 0, 0, 0, 0,
-                           0x43000ULL,
-                           0, 0, 0, 0, 0,
-                           0x44000ULL,
-                           0, 0
-};
-
 static void guest_code_initial(void)
 {
-       /* Round toward 0 */
-       uint32_t fpc = 0x11;
+       /* set several CRs to "safe" value */
+       unsigned long cr2_59 = 0x10;    /* enable guarded storage */
+       unsigned long cr8_63 = 0x1;     /* monitor mask = 1 */
+       unsigned long cr10 = 1;         /* PER START */
+       unsigned long cr11 = -1;        /* PER END */
+
 
        /* Dirty registers */
        asm volatile (
-               "       lctlg   0,15,%0\n"
-               "       sfpc    %1\n"
-               : : "Q" (crs), "d" (fpc));
+               "       lghi    2,0x11\n"       /* Round toward 0 */
+               "       sfpc    2\n"            /* set fpc to !=0 */
+               "       lctlg   2,2,%0\n"
+               "       lctlg   8,8,%1\n"
+               "       lctlg   10,10,%2\n"
+               "       lctlg   11,11,%3\n"
+               : : "m" (cr2_59), "m" (cr8_63), "m" (cr10), "m" (cr11) : "2");
        GUEST_SYNC(0);
 }