Add a test which modifies CMM page states while migration is in progress. Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx> Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx> --- s390x/Makefile | 1 + s390x/migration-during-cmm.c | 127 +++++++++++++++++++++++++++++++++++ s390x/unittests.cfg | 5 ++ 3 files changed, 133 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..1a8dc89f7b32 --- /dev/null +++ b/s390x/migration-during-cmm.c @@ -0,0 +1,127 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Perform CMMA actions while migrating. + * + * Copyright IBM Corp. 2022 + * + * Authors: + * Nico Boehr <nrb@xxxxxxxxxxxxx> + */ + +#include <libcflat.h> +#include <smp.h> +#include <asm-generic/barrier.h> + +#include "cmm.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(); + struct psw psw; + + 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; + } + + psw.mask = extract_psw_mask(); + psw.addr = (unsigned long)test_cmm_during_migration; + smp_cpu_setup(1, psw); + + 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