Re: [kvm-unit-tests PATCH v3 1/1] s390x: add migration test for storage keys

Nico Boehr
2022-06-01T07:30:11Z

On Tue, 31 May 2022 10:55:27 +0200
Thomas Huth <thuth@redhat.com> wrote:

> On 31/05/2022 10.37, Nico Boehr wrote:
> > Upon migration, we expect storage keys set by the guest to be
> > preserved, so add a test for it.
> >
> > We keep 128 pages and set predictable storage keys. Then, we
> > migrate and check that they can be read back and match the value
> > originally set.
> >
> > Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
> > Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> > ---
> > s390x/Makefile | 1 +
> > s390x/migration-skey.c | 76
> > ++++++++++++++++++++++++++++++++++++++++++ s390x/unittests.cfg |
> > 4 +++ 3 files changed, 81 insertions(+)
> > create mode 100644 s390x/migration-skey.c
> >
> > diff --git a/s390x/Makefile b/s390x/Makefile
> > index 25802428fa13..94fc5c1a3527 100644
> > --- a/s390x/Makefile
> > +++ b/s390x/Makefile
> > @@ -33,6 +33,7 @@ tests += $(TEST_DIR)/adtl-status.elf
> > tests += $(TEST_DIR)/migration.elf
> > tests += $(TEST_DIR)/pv-attest.elf
> > tests += $(TEST_DIR)/migration-cmm.elf
> > +tests += $(TEST_DIR)/migration-skey.elf
> >
> > pv-tests += $(TEST_DIR)/pv-diags.elf
> >
> > diff --git a/s390x/migration-skey.c b/s390x/migration-skey.c
> > new file mode 100644
> > index 000000000000..f846ac435836
> > --- /dev/null
> > +++ b/s390x/migration-skey.c
> > @@ -0,0 +1,76 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +/*
> > + * Storage Key migration tests
> > + *
> > + * Copyright IBM Corp. 2022
> > + *
> > + * Authors:
> > + * Nico Boehr <nrb@linux.ibm.com>
> > + */
> > +
> > +#include <libcflat.h>
> > +#include <asm/facility.h>
> > +#include <asm/page.h>
> > +#include <asm/mem.h>
> > +#include <asm/interrupt.h>
> > +#include <hardware.h>
> > +
> > +#define NUM_PAGES 128
> > +static uint8_t pagebuf[NUM_PAGES][PAGE_SIZE]
> > __attribute__((aligned(PAGE_SIZE))); +
> > +static void test_migration(void)
> > +{
> > + union skey expected_key, actual_key;
> > + int i, key_to_set;
> > +
> > + for (i = 0; i < NUM_PAGES; i++) {
> > + /*
> > + * Storage keys are 7 bit, lowest bit is always
> > returned as zero
> > + * by iske
> > + */
> > + key_to_set = i * 2;
> > + set_storage_key(pagebuf[i], key_to_set, 1);
> > + }
> > +
> > + puts("Please migrate me, then press return\n");
> > + (void)getchar();
> > +
> > + for (i = 0; i < NUM_PAGES; i++) {
> > + report_prefix_pushf("page %d", i);
> > +
> > + actual_key.val = get_storage_key(pagebuf[i]);
> > + expected_key.val = i * 2;
> > +
> > + /* ignore reference bit */
> > + actual_key.str.rf = 0;
> > + expected_key.str.rf = 0;
>
> If the reference bit gets always ignored, testing 64 pages should be
> enough? OTOH this will complicate the for-loop / creation of the key
> value, so I don't mind too much if we keep it this way.
>
> > + report(actual_key.val == expected_key.val,
> > "expected_key=0x%x actual_key=0x%x", expected_key.val,
> > actual_key.val); +
> > + report_prefix_pop();
> > + }
> > +}
> > +
> > +int main(void)
> > +{
> > + report_prefix_push("migration-skey");
> > + if (test_facility(169)) {
> > + report_skip("storage key removal facility is
> > active"); +
> > + /*
> > + * 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();
> > +
> > + goto done;
> > + }
> > +
> > + test_migration();
> > +
> > +done:
>
> } else {
> test_migration();
> }
>
> to get rid of the goto?
>
> > + report_prefix_pop();
> > + return report_summary();
> > +}
>
> Either way:
> Reviewed-by: Thomas Huth <thuth@redhat.com>
>