[kvm-unit-tests PATCH v3 0/2] s390x: add migration test for CMM

[kvm-unit-tests PATCH v3 0/2] s390x: add migration test for CMM

[Nico Boehr]

v2->v3:
---
* remove unneeded include asm-offsets.h (Thanks Claudio)
* change prefix of test to match filename (migration-cmm instead of
  cmm-migration)

v1->v2:
---
* Rename cmm-migration.c to migration-cmm.c (Thanks Janosch)
* Replace switch-case with unrolled loop (Thanks Claudio)
* Migrate even when ESSA is not available so we don't hang forever

Upon migration, we expect the CMM page states to be preserved. Add a test which
checks for that.

The new test gets a new file so the existing cmm test can still run when the
prerequisites for running migration tests aren't given (netcat). Therefore, move
some definitions to a common header to be able to re-use them.

Nico Boehr (2):
  lib: s390x: add header for CMM related defines
  s390x: add cmm migration test

 lib/s390x/asm/cmm.h   | 50 ++++++++++++++++++++++++++++
 s390x/Makefile        |  1 +
 s390x/cmm.c           | 25 ++------------
 s390x/migration-cmm.c | 77 +++++++++++++++++++++++++++++++++++++++++++
 s390x/unittests.cfg   |  4 +++
 5 files changed, 135 insertions(+), 22 deletions(-)
 create mode 100644 lib/s390x/asm/cmm.h
 create mode 100644 s390x/migration-cmm.c

-- 
2.31.1

[kvm-unit-tests PATCH v3 1/2] lib: s390x: add header for CMM related defines

[Nico Boehr]

Since we're going to need the definitions in an upcoming migration test for CMM,
add a header for CMM related defines. It is based on
arch/s390/include/asm/page-states.h from linux.

While at it, use the constants in existing calls to CMM related functions.

Also move essa() and test_availability() there to be able to use it outside
cmm.c.

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 lib/s390x/asm/cmm.h | 50 +++++++++++++++++++++++++++++++++++++++++++++
 s390x/cmm.c         | 25 +++--------------------
 2 files changed, 53 insertions(+), 22 deletions(-)
 create mode 100644 lib/s390x/asm/cmm.h

diff --git a/lib/s390x/asm/cmm.h b/lib/s390x/asm/cmm.h
new file mode 100644
index 000000000000..554a60031fbf
--- /dev/null
+++ b/lib/s390x/asm/cmm.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *    Copyright IBM Corp. 2017, 2022
+ *    Author(s): Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
+ *               Nico Boehr <nrb@linux.ibm.com>
+ */
+#include <asm/interrupt.h>
+
+#ifndef PAGE_STATES_H
+#define PAGE_STATES_H
+
+#define ESSA_GET_STATE			0
+#define ESSA_SET_STABLE			1
+#define ESSA_SET_UNUSED			2
+#define ESSA_SET_VOLATILE		3
+#define ESSA_SET_POT_VOLATILE		4
+#define ESSA_SET_STABLE_RESIDENT	5
+#define ESSA_SET_STABLE_IF_RESIDENT	6
+#define ESSA_SET_STABLE_NODAT		7
+
+#define ESSA_MAX	ESSA_SET_STABLE_NODAT
+
+#define ESSA_USAGE_STABLE		0
+#define ESSA_USAGE_UNUSED		1
+#define ESSA_USAGE_POT_VOLATILE		2
+#define ESSA_USAGE_VOLATILE		3
+
+static unsigned long essa(uint8_t state, unsigned long paddr)
+{
+	uint64_t extr_state;
+
+	asm volatile(".insn rrf,0xb9ab0000,%[extr_state],%[addr],%[new_state],0" \
+			: [extr_state] "=d" (extr_state) \
+			: [addr] "a" (paddr), [new_state] "i" (state));
+
+	return (unsigned long)extr_state;
+}
+
+/*
+ * Unfortunately the availability is not indicated by stfl bits, but
+ * we have to try to execute it and test for an operation exception.
+ */
+static inline bool check_essa_available(void)
+{
+	expect_pgm_int();
+	essa(ESSA_GET_STATE, 0);
+	return clear_pgm_int() == 0;
+}
+
+#endif
diff --git a/s390x/cmm.c b/s390x/cmm.c
index c3f0c931ae36..af852838851e 100644
--- a/s390x/cmm.c
+++ b/s390x/cmm.c
@@ -12,19 +12,10 @@
 #include <asm/asm-offsets.h>
 #include <asm/interrupt.h>
 #include <asm/page.h>
+#include <asm/cmm.h>
 
 static uint8_t pagebuf[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
 
-static unsigned long essa(uint8_t state, unsigned long paddr)
-{
-	uint64_t extr_state;
-
-	asm volatile(".insn rrf,0xb9ab0000,%[extr_state],%[addr],%[new_state],0"
-			: [extr_state] "=d" (extr_state)
-			: [addr] "a" (paddr), [new_state] "i" (state));
-	return (unsigned long)extr_state;
-}
-
 static void test_params(void)
 {
 	report_prefix_push("invalid ORC 8");
@@ -39,24 +30,14 @@ static void test_priv(void)
 	report_prefix_push("privileged");
 	expect_pgm_int();
 	enter_pstate();
-	essa(0, (unsigned long)pagebuf);
+	essa(ESSA_GET_STATE, (unsigned long)pagebuf);
 	check_pgm_int_code(PGM_INT_CODE_PRIVILEGED_OPERATION);
 	report_prefix_pop();
 }
 
-/* Unfortunately the availability is not indicated by stfl bits, but
- * we have to try to execute it and test for an operation exception.
- */
-static bool test_availability(void)
-{
-	expect_pgm_int();
-	essa(0, (unsigned long)pagebuf);
-	return clear_pgm_int() == 0;
-}
-
 int main(void)
 {
-	bool has_essa = test_availability();
+	bool has_essa = check_essa_available();
 
 	report_prefix_push("cmm");
 	if (!has_essa) {
-- 
2.31.1

[kvm-unit-tests PATCH v3 2/2] s390x: add cmm migration test

[Nico Boehr]

When a VM is migrated, we expect the page states to be preserved. Add a test
which checks for that.

Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
---
 s390x/Makefile        |  1 +
 s390x/migration-cmm.c | 77 +++++++++++++++++++++++++++++++++++++++++++
 s390x/unittests.cfg   |  4 +++
 3 files changed, 82 insertions(+)
 create mode 100644 s390x/migration-cmm.c

diff --git a/s390x/Makefile b/s390x/Makefile
index a8e04aa6fe4d..1877c8a6e86e 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -32,6 +32,7 @@ tests += $(TEST_DIR)/epsw.elf
 tests += $(TEST_DIR)/adtl-status.elf
 tests += $(TEST_DIR)/migration.elf
 tests += $(TEST_DIR)/pv-attest.elf
+tests += $(TEST_DIR)/migration-cmm.elf
 
 pv-tests += $(TEST_DIR)/pv-diags.elf
 
diff --git a/s390x/migration-cmm.c b/s390x/migration-cmm.c
new file mode 100644
index 000000000000..aa7910ca76bf
--- /dev/null
+++ b/s390x/migration-cmm.c
@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * CMM migration tests (ESSA)
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Authors:
+ *  Nico Boehr <nrb@linux.ibm.com>
+ */
+
+#include <libcflat.h>
+#include <asm/interrupt.h>
+#include <asm/page.h>
+#include <asm/cmm.h>
+#include <bitops.h>
+
+#define NUM_PAGES 128
+static uint8_t pagebuf[NUM_PAGES][PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
+
+static void test_migration(void)
+{
+	int i, state_mask, actual_state;
+	/*
+	 * Maps ESSA actions to states the page is allowed to be in after the
+	 * respective action was executed.
+	 */
+	int allowed_essa_state_masks[4] = {
+		BIT(ESSA_USAGE_STABLE),					/* ESSA_SET_STABLE */
+		BIT(ESSA_USAGE_UNUSED),					/* ESSA_SET_UNUSED */
+		BIT(ESSA_USAGE_VOLATILE),				/* ESSA_SET_VOLATILE */
+		BIT(ESSA_USAGE_VOLATILE) | BIT(ESSA_USAGE_POT_VOLATILE) /* ESSA_SET_POT_VOLATILE */
+	};
+
+	assert(NUM_PAGES % 4 == 0);
+	for (i = 0; i < NUM_PAGES; i += 4) {
+		essa(ESSA_SET_STABLE, (unsigned long)pagebuf[i]);
+		essa(ESSA_SET_UNUSED, (unsigned long)pagebuf[i + 1]);
+		essa(ESSA_SET_VOLATILE, (unsigned long)pagebuf[i + 2]);
+		essa(ESSA_SET_POT_VOLATILE, (unsigned long)pagebuf[i + 3]);
+	}
+
+	puts("Please migrate me, then press return\n");
+	(void)getchar();
+
+	for (i = 0; i < NUM_PAGES; i++) {
+		actual_state = essa(ESSA_GET_STATE, (unsigned long)pagebuf[i]);
+		/* extract the usage state in bits 60 and 61 */
+		actual_state = (actual_state >> 2) & 0x3;
+		state_mask = allowed_essa_state_masks[i % ARRAY_SIZE(allowed_essa_state_masks)];
+		report(BIT(actual_state) & state_mask, "page %d state: expected_mask=0x%x actual_mask=0x%lx", i, state_mask, BIT(actual_state));
+	}
+}
+
+int main(void)
+{
+	bool has_essa = check_essa_available();
+
+	report_prefix_push("migration-cmm");
+	if (!has_essa) {
+		report_skip("ESSA is not available");
+
+		/*
+		 * If we just exit and don't ask migrate_cmd to migrate us, it
+		 * will just hang forever. Hence, also ask for migration when we
+		 * skip this test alltogether.
+		 */
+		puts("Please migrate me, then press return\n");
+		(void)getchar();
+
+		goto done;
+	}
+
+	test_migration();
+done:
+	report_prefix_pop();
+	return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index b456b2881448..9b97d0471bcf 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -176,3 +176,7 @@ extra_params = -cpu qemu,gs=off,vx=off
 file = migration.elf
 groups = migration
 smp = 2
+
+[migration-cmm]
+file = migration-cmm.elf
+groups = migration
-- 
2.31.1

Re: [kvm-unit-tests PATCH v3 0/2] s390x: add migration test for CMM

[Claudio Imbrenda]

On Thu, 12 May 2022 15:42:31 +0200
Nico Boehr <nrb@linux.ibm.com> wrote:

> v2->v3:
> ---
> * remove unneeded include asm-offsets.h (Thanks Claudio)
> * change prefix of test to match filename (migration-cmm instead of
>   cmm-migration)
> 
> v1->v2:
> ---
> * Rename cmm-migration.c to migration-cmm.c (Thanks Janosch)
> * Replace switch-case with unrolled loop (Thanks Claudio)
> * Migrate even when ESSA is not available so we don't hang forever
> 
> Upon migration, we expect the CMM page states to be preserved. Add a test which
> checks for that.
> 
> The new test gets a new file so the existing cmm test can still run when the
> prerequisites for running migration tests aren't given (netcat). Therefore, move
> some definitions to a common header to be able to re-use them.
> 

thanks, queued

> Nico Boehr (2):
>   lib: s390x: add header for CMM related defines
>   s390x: add cmm migration test
> 
>  lib/s390x/asm/cmm.h   | 50 ++++++++++++++++++++++++++++
>  s390x/Makefile        |  1 +
>  s390x/cmm.c           | 25 ++------------
>  s390x/migration-cmm.c | 77 +++++++++++++++++++++++++++++++++++++++++++
>  s390x/unittests.cfg   |  4 +++
>  5 files changed, 135 insertions(+), 22 deletions(-)
>  create mode 100644 lib/s390x/asm/cmm.h
>  create mode 100644 s390x/migration-cmm.c
>