On Tue, 22 Nov 2022 17:12:43 +0100 Nico Boehr <nrb@xxxxxxxxxxxxx> wrote: > Add a test which modifies CMM page states while migration is in > progress. > > Signed-off-by: Nico Boehr <nrb@xxxxxxxxxxxxx> > --- > s390x/Makefile | 1 + > s390x/migration-during-cmm.c | 111 +++++++++++++++++++++++++++++++++++ > s390x/unittests.cfg | 5 ++ > 3 files changed, 117 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..3c96283d7b00 > --- /dev/null > +++ b/s390x/migration-during-cmm.c > @@ -0,0 +1,111 @@ > +/* 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 is 128 enough to allow multiple iterations of the thread? > + > +static uint8_t pagebuf[NUM_PAGES * PAGE_SIZE] __attribute__((aligned(PAGE_SIZE))); > + > +static int thread_iters; please make all ints unsigned unless you really need them signed > +static int thread_should_exit; > +static int thread_exited; (these are fine as is, since they are only used as flags) > +static bool verification_failure_occured; > +struct cmm_verify_result result; > + > +static void test_cmm_during_migration(void) > +{ > + /* > + * The second CPU must not print on the console, otherwise it will race with > + * the primary CPU on the SCLP buffer. > + */ > + while (!thread_should_exit) { > + cmm_set_page_states(pagebuf, NUM_PAGES); I would do (pagebuf + (thread_iters % 4) * PAGE_SIZE this way you will actually change the values for each page at each iteration (will need a bigger buffer) > + if (!cmm_verify_page_states(pagebuf, NUM_PAGES, &result)) { > + verification_failure_occured = true; > + goto out; > + } > + thread_iters++; > + } > + > +out: > + thread_exited = 1; > +} > + > +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); > + > + puts("Please migrate me, then press return\n"); > + (void)getchar(); > + > + thread_should_exit = 1; I would use WRITE_ONCE, otherwise you probably need a mb() here > + > + while (!thread_exited) > + mb(); > + > + report_info("thread completed %d iterations", thread_iters); > + > + report_prefix_push("during migration"); > + if (verification_failure_occured) > + cmm_report_verify_fail(&result); > + else > + report_pass("page states matched"); > + 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"); > + if (!cmm_verify_page_states(pagebuf, NUM_PAGES, &result)) pagebuf + ((thread_iters - 1) % 4) * PAGE_SIZE > + cmm_report_verify_fail(&result); > + else > + report_pass("page states matched"); > + report_prefix_pop(); > + > + goto done; > + > +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 alltogether. > + */ > + puts("Please migrate me, then press return\n"); > + (void)getchar(); > + > +done: > + 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