Right now, we have a test which sets storage keys, then migrates the VM
and - after migration finished - verifies the skeys are still there.
Add a new version of the test which changes storage keys while the
migration is in progress. This is achieved by adding a command line
argument to the existing migration-skey test.
Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx>
---
s390x/migration-skey.c | 214 +++++++++++++++++++++++++++++++++++------
s390x/unittests.cfg | 15 ++-
2 files changed, 198 insertions(+), 31 deletions(-)
diff --git a/s390x/migration-skey.c b/s390x/migration-skey.c
index b7bd82581abe..9b9a45f4ad3b 100644
--- a/s390x/migration-skey.c
+++ b/s390x/migration-skey.c
@@ -2,6 +2,12 @@
/*
* Storage Key migration tests
*
+ * There are two variants of this test:
+ * - sequential: sets some storage keys on pages, migrates the VM and then
+ * verifies the storage keys are still as we expect.
+ * - parallel: start migration of a VM and set and check storage keys on some
+ * pages while migration is in process.
+ *
* Copyright IBM Corp. 2022
*
* Authors:
@@ -10,20 +16,44 @@
#include <libcflat.h>
#include <asm/facility.h>
-#include <asm/page.h>
#include <asm/mem.h>
-#include <asm/interrupt.h>
+#include <asm/page.h>
+#include <asm/barrier.h>
#include <hardware.h>
+#include <smp.h>
+
+struct skey_verify_result {
+ bool verify_failed;
+ union skey expected_key;
+ union skey actual_key;
+ unsigned long page_mismatch_idx;
+ unsigned long page_mismatch_addr;
+};
#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 struct skey_verify_result result;
-static void test_migration(void)
+static unsigned int thread_iters;
+static bool thread_should_exit;
+static bool thread_exited;
+
+/*
+ * Set storage key test pattern on pagebuf with a seed for the storage keys.
+ *
+ * Each page's storage key is generated by taking the page's index in pagebuf,
+ * XOR-ing that with the given seed and then multipling the result with two.
+ *
+ * pagebuf must point to page_count consecutive pages.
+ * Only the lower seven bits of the seed are considered.
+ */
+static void skey_set_test_pattern(uint8_t *pagebuf, unsigned long page_count, unsigned char seed)
{
- union skey expected_key, actual_key;
- int i, key_to_set, key_mismatches = 0;
+ unsigned char key_to_set;
+ unsigned long i;
- for (i = 0; i < NUM_PAGES; i++) {
+ for (i = 0; i < page_count; i++) {
/*
* Storage keys are 7 bit, lowest bit is always returned as zero
* by iske.
@@ -31,16 +61,34 @@ static void test_migration(void)
* protection as well as reference and change indication for
* some keys.
*/
- key_to_set = i * 2;
- set_storage_key(pagebuf[i], key_to_set, 1);
+ key_to_set = (i ^ seed) * 2;
+ set_storage_key(pagebuf + i * PAGE_SIZE, key_to_set, 1);
}
+}
- puts("Please migrate me, then press return\n");
- (void)getchar();
+/*
+ * Verify storage keys on pagebuf.
+ * Storage keys must have been set by skey_set_test_pattern on pagebuf before.
+ * skey_set_keys must have been called with the same seed value.
+ *
+ * If storage keys match the expected result, will return a skey_verify_result
+ * with verify_failed false. All other fields are then invalid.
+ * If there is a mismatch, returned struct will have verify_failed true and will
+ * be filled with the details on the first mismatch encountered.
+ */
+static struct skey_verify_result skey_verify_test_pattern(uint8_t *pagebuf, unsigned long page_count, unsigned char seed)
+{
+ union skey expected_key, actual_key;
+ struct skey_verify_result result = {
+ .verify_failed = true
+ };
+ uint8_t *cur_page;
+ unsigned long i;
- for (i = 0; i < NUM_PAGES; i++) {
- actual_key.val = get_storage_key(pagebuf[i]);
- expected_key.val = i * 2;
+ for (i = 0; i < page_count; i++) {
+ cur_page = pagebuf + i * PAGE_SIZE;
+ actual_key.val = get_storage_key(cur_page);
+ expected_key.val = (i ^ seed) * 2;
/*
* The PoP neither gives a guarantee that the reference bit is
@@ -51,33 +99,145 @@ static void test_migration(void)
actual_key.str.rf = 0;
expected_key.str.rf = 0;
- /* don't log anything when key matches to avoid spamming the log */
if (actual_key.val != expected_key.val) {
- key_mismatches++;
- report_fail("page %d expected_key=0x%x actual_key=0x%x", i, expected_key.val, actual_key.val);
+ result.expected_key.val = expected_key.val;
+ result.actual_key.val = actual_key.val;
+ result.page_mismatch_idx = i;
+ result.page_mismatch_addr = (unsigned long)cur_page;
+ return result;
}
}
- report(!key_mismatches, "skeys after migration match");
+ result.verify_failed = false;
+ return result;
+}
+
+static void skey_report_verify(struct skey_verify_result * const result)
+{
+ if (result->verify_failed)
+ report_fail("page skey mismatch: first page idx = %lu, addr = 0x%lx, "
+ "expected_key = 0x%x, actual_key = 0x%x",
+ result->page_mismatch_idx, result->page_mismatch_addr,
+ result->expected_key.val, result->actual_key.val);
+ else
+ report_pass("skeys match");
+}
+
+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)
+static void test_skey_migration_sequential(void)
+{
+ report_prefix_push("sequential");
+
+ skey_set_test_pattern(pagebuf, NUM_PAGES, 0);
+
+ migrate_once();
+
+ result = skey_verify_test_pattern(pagebuf, NUM_PAGES, 0);
+ skey_report_verify(&result);
+
+ report_prefix_pop();
+}
+
+static void set_skeys_thread(void)
+{
+ while (!READ_ONCE(thread_should_exit)) {
+ skey_set_test_pattern(pagebuf, NUM_PAGES, thread_iters);
+
+ result = skey_verify_test_pattern(pagebuf, NUM_PAGES, thread_iters);
+
+ /*
+ * 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++;
+
+ if (result.verify_failed)
+ break;
+ }
+
+ WRITE_ONCE(thread_exited, 1);
+}
+
+static void test_skey_migration_parallel(void)
+{
+ report_prefix_push("parallel");
+
+ 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(set_skeys_thread));
+
+ 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");
+ skey_report_verify(&result);
+ report_prefix_pop();
+
+ /*
+ * Verification of skeys 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 skeys which might not have been migrated
+ * correctly.
+ */
+ report_prefix_push("after migration");
+ assert(thread_iters > 0);
+ result = skey_verify_test_pattern(pagebuf, NUM_PAGES, thread_iters - 1);
+ skey_report_verify(&result);
+ report_prefix_pop();
+
+error:
+ report_prefix_pop();
+}
+
+static void print_usage(void)
+{
+ report_info("Usage: migration-skey [parallel|sequential]");
+}
+
+int main(int argc, char **argv)
{
report_prefix_push("migration-skey");
if (test_facility(169)) {
report_skip("storage key removal facility is active");
+ goto 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.
- */
- puts("Please migrate me, then press return\n");
- (void)getchar();
+ if (argc < 2) {
+ print_usage();
+ goto error;
+ }
+
+ if (!strcmp("parallel", argv[1])) {
+ test_skey_migration_parallel();
+ } else if (!strcmp("sequential", argv[1])) {
+ test_skey_migration_sequential();
} else {
- test_migration();
+ print_usage();
}
+error:
+ migrate_once();
report_prefix_pop();
return report_summary();
}
diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
index 3caf81eda396..7763cb857954 100644
--- a/s390x/unittests.cfg
+++ b/s390x/unittests.cfg
@@ -185,10 +185,6 @@ smp = 2
file = migration-cmm.elf
groups = migration
-[migration-skey]
-file = migration-skey.elf
-groups = migration
-
[panic-loop-extint]
file = panic-loop-extint.elf
groups = panic
@@ -208,3 +204,14 @@ groups = migration
[exittime]
file = exittime.elf
smp = 2
+
+[migration-skey-sequential]
+file = migration-skey.elf
+groups = migration
+extra_params = -append 'sequential'
+
+[migration-skey-parallel]
+file = migration-skey.elf
+smp = 2
+groups = migration
+extra_params = -append 'parallel'
--
2.36.1
