An invalid PSW causes a program interrupt. When an invalid PSW is
introduced in the pgm_new_psw, an interrupt loop occurs as soon as a
program interrupt is caused.
QEMU should detect that and panic the guest, hence add a test for it.
Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx>
---
s390x/Makefile | 1 +
s390x/panic-loop-pgm.c | 53 ++++++++++++++++++++++++++++++++++++++++++
s390x/unittests.cfg | 6 +++++
3 files changed, 60 insertions(+)
create mode 100644 s390x/panic-loop-pgm.c
diff --git a/s390x/Makefile b/s390x/Makefile
index e4649da50d9d..66415d0b588d 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -35,6 +35,7 @@ tests += $(TEST_DIR)/pv-attest.elf
tests += $(TEST_DIR)/migration-cmm.elf
tests += $(TEST_DIR)/migration-skey.elf
tests += $(TEST_DIR)/panic-loop-extint.elf
+tests += $(TEST_DIR)/panic-loop-pgm.elf
pv-tests += $(TEST_DIR)/pv-diags.elf
diff --git a/s390x/panic-loop-pgm.c b/s390x/panic-loop-pgm.c
new file mode 100644
index 000000000000..68934057a251
--- /dev/null
+++ b/s390x/panic-loop-pgm.c
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Program interrupt loop test
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Authors:
+ * Nico Boehr <nrb@xxxxxxxxxxxxx>
+ */
+#include <libcflat.h>
+#include <bitops.h>
+#include <asm/interrupt.h>
+#include <asm/barrier.h>
+#include <hardware.h>
+
+static void pgm_int_handler(void)
+{
+ /*
+ * return to pgm_old_psw. This gives us the chance to print the return_fail
+ * in case something goes wrong.
+ */
+ asm volatile (
+ "lpswe %[pgm_old_psw]\n"
+ :
+ : [pgm_old_psw] "Q"(lowcore.pgm_old_psw)
+ : "memory"
+ );
+}
+
+int main(void)
+{
+ report_prefix_push("panic-loop-pgm");
+
+ if (!host_is_qemu() || host_is_tcg()) {
+ report_skip("QEMU-KVM-only test");
+ goto out;
+ }
+
+ lowcore.pgm_new_psw.addr = (uint64_t) pgm_int_handler;
+ /* bit 12 set is invalid */
+ lowcore.pgm_new_psw.mask = extract_psw_mask() | BIT(63 - 12);
+ mb();
+
+ /* cause a pgm int */
+ *((int *)-4) = 0x42;
+ mb();
+
+ report_fail("survived pgmint loop");
+
+out:
+ report_prefix_pop();
+ return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index 53aeb94f382c..0f7d830220d7 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -190,3 +190,9 @@ file = panic-loop-extint.elf
groups = panic
accel = kvm
timeout = 5
+
+[panic-loop-pgm]
+file = panic-loop-pgm.elf
+groups = panic
+accel = kvm
+timeout = 5
--
2.36.1
