[kvm-unit-tests,GIT,PULL,13/13] s390x: cmm: test no-translate bit after reset

Commit Message

Nico Boehr April 24, 2024, 10:59 a.m. UTC

KVM did not properly reset the no-translate bit after reset, see
https://lore.kernel.org/kvm/[e-mail]/

Add a test which performs a load normal reset (includes a subsystem
reset) and verify that this clears the no-translate bit.

Reviewed-by: Claudio Imbrenda <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Nico Boehr <[e-mail]>
---
 s390x/cmm.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

Patch

diff --git a/s390x/cmm.c b/s390x/cmm.c
index af852838..536f2bfc 100644
--- a/s390x/cmm.c
+++ b/s390x/cmm.c
@@ -9,13 +9,17 @@ 
  */
 
 #include <libcflat.h>
+#include <bitops.h>
 #include <asm/asm-offsets.h>
 #include <asm/interrupt.h>
 #include <asm/page.h>
 #include <asm/cmm.h>
+#include <asm/facility.h>
 
 static uint8_t pagebuf[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
 
+extern int diag308_load_reset(u64);
+
 static void test_params(void)
 {
 	report_prefix_push("invalid ORC 8");
@@ -35,6 +39,35 @@  static void test_priv(void)
 	report_prefix_pop();
 }
 
+static void test_reset_no_translate(void)
+{
+	const uint64_t mask_no_translate = BIT(63 - 58);
+	unsigned long state;
+
+	if (!test_facility(147)) {
+		report_prefix_push("no-translate unavailable");
+		expect_pgm_int();
+		essa(ESSA_SET_STABLE_NODAT, (unsigned long)pagebuf);
+		check_pgm_int_code(PGM_INT_CODE_SPECIFICATION);
+		report_prefix_pop();
+		return;
+	}
+
+	report_prefix_push("reset no-translate");
+	essa(ESSA_SET_STABLE_NODAT, (unsigned long)pagebuf);
+
+	state = essa(ESSA_GET_STATE, (unsigned long)pagebuf);
+	report(state & mask_no_translate, "no-translate bit set before reset");
+
+	/* Load normal reset - includes subsystem reset */
+	diag308_load_reset(1);
+
+	state = essa(ESSA_GET_STATE, (unsigned long)pagebuf);
+	report(!(state & mask_no_translate), "no-translate bit unset after reset");
+
+	report_prefix_pop();
+}
+
 int main(void)
 {
 	bool has_essa = check_essa_available();
@@ -47,6 +80,7 @@  int main(void)
 
 	test_priv();
 	test_params();
+	test_reset_no_translate();
 done:
 	report_prefix_pop();
 	return report_summary();