[kvm-unit-tests PATCH v5 4/4] s390x: add pgm spec interrupt loop test

[Nico Boehr <nrb@linux.ibm.com>]

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@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 s390x/Makefile         |  1 +
 s390x/panic-loop-pgm.c | 38 ++++++++++++++++++++++++++++++++++++++
 s390x/unittests.cfg    |  6 ++++++
 3 files changed, 45 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..23e973477f68
--- /dev/null
+++ b/s390x/panic-loop-pgm.c
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Program interrupt loop test
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Authors:
+ *  Nico Boehr <nrb@linux.ibm.com>
+ */
+#include <libcflat.h>
+#include <bitops.h>
+#include <asm/interrupt.h>
+#include <asm/barrier.h>
+#include <hardware.h>
+
+int main(void)
+{
+	report_prefix_push("panic-loop-pgm");
+
+	if (!host_is_qemu() || host_is_tcg()) {
+		report_skip("QEMU-KVM-only test");
+		goto out;
+	}
+
+	expect_pgm_int();
+	/* bit 12 set is invalid */
+	lowcore.pgm_new_psw.mask = extract_psw_mask() | BIT(63 - 12);
+	mb();
+
+	/* cause a pgm int */
+	psw_mask_set_bits(BIT(63 - 12));
+
+	report_fail("survived pgm int loop");
+
+out:
+	report_prefix_pop();
+	return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index b1b25f118ff6..f9f102abfa89 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -191,3 +191,9 @@ 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