* [kvm-unit-tests PATCH v4 1/2] s390x: add a library for CMM-related functions
2022-12-01 9:17 [kvm-unit-tests PATCH v4 0/2] s390x: test CMM during migration Nico Boehr
@ 2022-12-01 9:17 ` Nico Boehr
2022-12-01 9:17 ` [kvm-unit-tests PATCH v4 2/2] s390x: add CMM test during migration Nico Boehr
1 sibling, 0 replies; 3+ messages in thread
From: Nico Boehr @ 2022-12-01 9:17 UTC (permalink / raw)
To: kvm; +Cc: frankja, imbrenda, thuth
Upcoming changes will add a test which is very similar to the existing
CMM migration test. To reduce code duplication, move the common function
to a library which can be re-used by both tests.
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
lib/s390x/cmm.c | 92 +++++++++++++++++++++++++++++++++++++++++++
lib/s390x/cmm.h | 31 +++++++++++++++
s390x/Makefile | 1 +
s390x/migration-cmm.c | 33 ++++------------
4 files changed, 131 insertions(+), 26 deletions(-)
create mode 100644 lib/s390x/cmm.c
create mode 100644 lib/s390x/cmm.h
diff --git a/lib/s390x/cmm.c b/lib/s390x/cmm.c
new file mode 100644
index 000000000000..f6c01b3467e8
--- /dev/null
+++ b/lib/s390x/cmm.c
@@ -0,0 +1,92 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * CMM test library
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Authors:
+ * Nico Boehr <nrb@linux.ibm.com>
+ */
+#include <libcflat.h>
+#include <bitops.h>
+#include "cmm.h"
+
+/*
+ * Maps ESSA actions to states the page is allowed to be in after the
+ * respective action was executed.
+ */
+static const unsigned long 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 */
+};
+
+/*
+ * Set CMM page states on pagebuf.
+ * pagebuf must point to page_count consecutive pages.
+ * page_count must be a multiple of 4.
+ */
+void cmm_set_page_states(uint8_t *pagebuf, unsigned long page_count)
+{
+ unsigned long addr = (unsigned long)pagebuf;
+ unsigned long i;
+
+ assert(page_count % 4 == 0);
+ for (i = 0; i < page_count; i += 4) {
+ essa(ESSA_SET_STABLE, addr + i * PAGE_SIZE);
+ essa(ESSA_SET_UNUSED, addr + (i + 1) * PAGE_SIZE);
+ essa(ESSA_SET_VOLATILE, addr + (i + 2) * PAGE_SIZE);
+ essa(ESSA_SET_POT_VOLATILE, addr + (i + 3) * PAGE_SIZE);
+ }
+}
+
+/*
+ * Verify CMM page states on pagebuf.
+ * Page states must have been set by cmm_set_page_states on pagebuf before.
+ * page_count must be a multiple of 4.
+ *
+ * If page states match the expected result, will return a cmm_verify_result
+ * with verify_failed false. All other fields are then invalid.
+ * If there is a mismatch, the returned struct will have verify_failed true
+ * and will be filled with details on the first mismatch encountered.
+ */
+struct cmm_verify_result cmm_verify_page_states(uint8_t *pagebuf, unsigned long page_count)
+{
+ struct cmm_verify_result result = {
+ .verify_failed = true
+ };
+ unsigned long expected_mask, actual_mask;
+ unsigned long addr, i;
+
+ assert(page_count % 4 == 0);
+
+ for (i = 0; i < page_count; i++) {
+ addr = (unsigned long)(pagebuf + i * PAGE_SIZE);
+ actual_mask = essa(ESSA_GET_STATE, addr);
+ /* usage state in bits 60 and 61 */
+ actual_mask = BIT((actual_mask >> 2) & 0x3);
+ expected_mask = allowed_essa_state_masks[i % ARRAY_SIZE(allowed_essa_state_masks)];
+ if (!(actual_mask & expected_mask)) {
+ result.page_mismatch_idx = i;
+ result.page_mismatch_addr = addr;
+ result.expected_mask = expected_mask;
+ result.actual_mask = actual_mask;
+ return result;
+ }
+ }
+
+ result.verify_failed = false;
+ return result;
+}
+
+void cmm_report_verify(const struct cmm_verify_result *result)
+{
+ if (result->verify_failed)
+ report_fail("page state mismatch: first page idx = %lu, addr = %lx, "
+ "expected_mask = 0x%x, actual_mask = 0x%x",
+ result->page_mismatch_idx, result->page_mismatch_addr,
+ result->expected_mask, result->actual_mask);
+ else
+ report_pass("page states match");
+}
diff --git a/lib/s390x/cmm.h b/lib/s390x/cmm.h
new file mode 100644
index 000000000000..a14e6afe809c
--- /dev/null
+++ b/lib/s390x/cmm.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * CMM test library
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Authors:
+ * Nico Boehr <nrb@linux.ibm.com>
+ */
+#ifndef S390X_CMM_H
+#define S390X_CMM_H
+
+#include <libcflat.h>
+#include <asm/page.h>
+#include <asm/cmm.h>
+
+struct cmm_verify_result {
+ bool verify_failed;
+ char expected_mask;
+ char actual_mask;
+ unsigned long page_mismatch_idx;
+ unsigned long page_mismatch_addr;
+};
+
+void cmm_set_page_states(uint8_t *pagebuf, unsigned long page_count);
+
+struct cmm_verify_result cmm_verify_page_states(uint8_t *pagebuf, unsigned long page_count);
+
+void cmm_report_verify(const struct cmm_verify_result *result);
+
+#endif /* S390X_CMM_H */
diff --git a/s390x/Makefile b/s390x/Makefile
index bf1504f9d58c..401cb6371cee 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -99,6 +99,7 @@ cflatobjs += lib/s390x/malloc_io.o
cflatobjs += lib/s390x/uv.o
cflatobjs += lib/s390x/sie.o
cflatobjs += lib/s390x/fault.o
+cflatobjs += lib/s390x/cmm.o
OBJDIRS += lib/s390x
diff --git a/s390x/migration-cmm.c b/s390x/migration-cmm.c
index aa7910ca76bf..541abd31f46a 100644
--- a/s390x/migration-cmm.c
+++ b/s390x/migration-cmm.c
@@ -9,46 +9,27 @@
*/
#include <libcflat.h>
+#include <cmm.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 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 */
- };
+ struct cmm_verify_result result;
- 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]);
- }
+ cmm_set_page_states(pagebuf, NUM_PAGES);
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));
- }
+ result = cmm_verify_page_states(pagebuf, NUM_PAGES);
+ cmm_report_verify(&result);
}
int main(void)
--
2.36.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* [kvm-unit-tests PATCH v4 2/2] s390x: add CMM test during migration
2022-12-01 9:17 [kvm-unit-tests PATCH v4 0/2] s390x: test CMM during migration Nico Boehr
2022-12-01 9:17 ` [kvm-unit-tests PATCH v4 1/2] s390x: add a library for CMM-related functions Nico Boehr
@ 2022-12-01 9:17 ` Nico Boehr
1 sibling, 0 replies; 3+ messages in thread
From: Nico Boehr @ 2022-12-01 9:17 UTC (permalink / raw)
To: kvm; +Cc: frankja, imbrenda, thuth
Add a test which modifies CMM page states while migration is in
progress.
Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
s390x/Makefile | 1 +
s390x/migration-during-cmm.c | 123 +++++++++++++++++++++++++++++++++++
s390x/unittests.cfg | 5 ++
3 files changed, 129 insertions(+)
create mode 100644 s390x/migration-during-cmm.c
diff --git a/s390x/Makefile b/s390x/Makefile
index 401cb6371cee..64c7c04409ae 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -39,6 +39,7 @@ tests += $(TEST_DIR)/panic-loop-extint.elf
tests += $(TEST_DIR)/panic-loop-pgm.elf
tests += $(TEST_DIR)/migration-sck.elf
tests += $(TEST_DIR)/exittime.elf
+tests += $(TEST_DIR)/migration-during-cmm.elf
pv-tests += $(TEST_DIR)/pv-diags.elf
diff --git a/s390x/migration-during-cmm.c b/s390x/migration-during-cmm.c
new file mode 100644
index 000000000000..7e1f9590ae50
--- /dev/null
+++ b/s390x/migration-during-cmm.c
@@ -0,0 +1,123 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Perform CMMA actions while migrating.
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Authors:
+ * Nico Boehr <nrb@linux.ibm.com>
+ */
+
+#include <libcflat.h>
+#include <smp.h>
+#include <cmm.h>
+#include <asm-generic/barrier.h>
+
+#define NUM_PAGES 128
+
+/*
+ * Allocate 3 pages more than we need so we can start at different offsets.
+ * This ensures page states change on every loop iteration.
+ */
+static uint8_t pagebuf[(NUM_PAGES + 3) * PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
+
+static unsigned int thread_iters;
+static int thread_should_exit;
+static int thread_exited;
+struct cmm_verify_result result;
+
+static void test_cmm_during_migration(void)
+{
+ uint8_t *pagebuf_start;
+ /*
+ * The second CPU must not print to the console, otherwise it will race with
+ * the primary CPU on the SCLP buffer.
+ */
+ while (!READ_ONCE(thread_should_exit)) {
+ /*
+ * Start on a offset different from the last iteration so page states change with
+ * every iteration. This is why pagebuf has 3 extra pages.
+ */
+ pagebuf_start = pagebuf + (thread_iters % 4) * PAGE_SIZE;
+ cmm_set_page_states(pagebuf_start, NUM_PAGES);
+
+ /*
+ * Always increment even if the verify fails. This ensures primary CPU knows where
+ * we left off and can do an additional verify round after migration finished.
+ */
+ thread_iters++;
+
+ result = cmm_verify_page_states(pagebuf_start, NUM_PAGES);
+ if (result.verify_failed)
+ break;
+ }
+
+ WRITE_ONCE(thread_exited, 1);
+}
+
+static void migrate_once(void)
+{
+ static bool migrated;
+
+ if (migrated)
+ return;
+
+ migrated = true;
+ puts("Please migrate me, then press return\n");
+ (void)getchar();
+}
+
+int main(void)
+{
+ bool has_essa = check_essa_available();
+
+ report_prefix_push("migration-during-cmm");
+ if (!has_essa) {
+ report_skip("ESSA is not available");
+ goto error;
+ }
+
+ if (smp_query_num_cpus() == 1) {
+ report_skip("need at least 2 cpus for this test");
+ goto error;
+ }
+
+ smp_cpu_setup(1, PSW_WITH_CUR_MASK(test_cmm_during_migration));
+
+ migrate_once();
+
+ WRITE_ONCE(thread_should_exit, 1);
+
+ while (!thread_exited)
+ mb();
+
+ report_info("thread completed %u iterations", thread_iters);
+
+ report_prefix_push("during migration");
+ cmm_report_verify(&result);
+ report_prefix_pop();
+
+ /*
+ * Verification of page states occurs on the thread. We don't know if we
+ * were still migrating during the verification.
+ * To be sure, make another verification round after the migration
+ * finished to catch page states which might not have been migrated
+ * correctly.
+ */
+ report_prefix_push("after migration");
+ assert(thread_iters > 0);
+ result = cmm_verify_page_states(pagebuf + ((thread_iters - 1) % 4) * PAGE_SIZE, NUM_PAGES);
+ cmm_report_verify(&result);
+ report_prefix_pop();
+
+error:
+ /*
+ * 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 altogether.
+ */
+ migrate_once();
+
+ report_prefix_pop();
+ return report_summary();
+}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index 3caf81eda396..f6889bd4da01 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -208,3 +208,8 @@ groups = migration
[exittime]
file = exittime.elf
smp = 2
+
+[migration-during-cmm]
+file = migration-during-cmm.elf
+groups = migration
+smp = 2
--
2.36.1
^ permalink raw reply related [flat|nested] 3+ messages in thread