From: Nico Boehr <nrb@xxxxxxxxxxxxx> 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> Reviewed-by: Nina Schoetterl-Glausch <nsg@xxxxxxxxxxxxx> Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20221220083030.30153-2-nrb@xxxxxxxxxxxxx Message-Id: <20221220083030.30153-2-nrb@xxxxxxxxxxxxx> Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> --- s390x/migration-skey.c | 218 +++++++++++++++++++++++++++++++++++++---- s390x/unittests.cfg | 15 ++- 2 files changed, 210 insertions(+), 23 deletions(-) diff --git a/s390x/migration-skey.c b/s390x/migration-skey.c index a91eb6b5..8d6d8ecf 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: set storage keys on some pages, migrates the VM and then + * verifies that the storage keys are still as we expect. + * - parallel: start migration and set and check storage keys on some + * pages while migration is in process. + * * Copyright IBM Corp. 2022 * * Authors: @@ -13,16 +19,45 @@ #include <asm/facility.h> #include <asm/page.h> #include <asm/mem.h> -#include <asm/interrupt.h> +#include <asm/barrier.h> #include <hardware.h> +#include <smp.h> + +struct 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 verify_result result; + +static unsigned int thread_iters; +static bool thread_should_exit; +static bool thread_exited; + +static enum { + TEST_INVALID, + TEST_SEQUENTIAL, + TEST_PARALLEL +} arg_test_to_run; -static void test_migration(void) +/* + * 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. + * + * Only the lower seven bits of the seed are considered. + */ +static void set_test_pattern(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++) { /* @@ -32,15 +67,34 @@ 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); } +} - migrate_once(); +/* + * Verify storage keys on pagebuf. + * Storage keys must have been set by set_test_pattern on pagebuf before. + * set_test_pattern must have been called with the same seed value. + * + * If storage keys match the expected result, will return a 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 verify_result verify_test_pattern(unsigned char seed) +{ + union skey expected_key, actual_key; + struct 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; + 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 @@ -51,27 +105,153 @@ 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 report_verify_result(const struct verify_result * result) +{ + if (result->verify_failed) + report_fail("page skey mismatch: first page idx = %lu, addr = 0x%lx, " + "expected_key = 0x%02x, actual_key = 0x%02x", + result->page_mismatch_idx, result->page_mismatch_addr, + result->expected_key.val, result->actual_key.val); + else + report_pass("skeys match"); +} + +static void test_skey_migration_sequential(void) +{ + report_prefix_push("sequential"); + + set_test_pattern(0); + + migrate_once(); + + result = verify_test_pattern(0); + report_verify_result(&result); + + report_prefix_pop(); +} + +static void set_skeys_thread(void) +{ + while (!READ_ONCE(thread_should_exit)) { + set_test_pattern(thread_iters); + + result = verify_test_pattern(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 (!READ_ONCE(thread_exited)) + ; + + /* Ensure we read result and thread_iters below from memory after thread exited */ + mb(); + report_info("thread completed %u iterations", thread_iters); + + report_prefix_push("during migration"); + report_verify_result(&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 = verify_test_pattern(thread_iters - 1); + report_verify_result(&result); + report_prefix_pop(); + +error: + report_prefix_pop(); +} + +static void print_usage(void) +{ + report_info("Usage: migration-skey [--parallel|--sequential]"); +} + +static void parse_args(int argc, char **argv) +{ + if (argc < 2) { + /* default to sequential since it only needs one cpu */ + arg_test_to_run = TEST_SEQUENTIAL; + return; + } + + if (!strcmp("--parallel", argv[1])) + arg_test_to_run = TEST_PARALLEL; + else if (!strcmp("--sequential", argv[1])) + arg_test_to_run = TEST_SEQUENTIAL; + else + arg_test_to_run = TEST_INVALID; } -int main(void) +int main(int argc, char **argv) { report_prefix_push("migration-skey"); - if (test_facility(169)) + if (test_facility(169)) { report_skip("storage key removal facility is active"); - else - test_migration(); + goto error; + } - migrate_once(); + parse_args(argc, argv); + + switch (arg_test_to_run) { + case TEST_SEQUENTIAL: + test_skey_migration_sequential(); + break; + case TEST_PARALLEL: + test_skey_migration_parallel(); + break; + default: + print_usage(); + break; + } +error: + migrate_once(); report_prefix_pop(); return report_summary(); } diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg index 3caf81ed..d97eb5e9 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' -- 2.39.0
