Re: [kvm-unit-tests PATCH v1 2/2] s390x: add cmm migration test

Claudio Imbrenda
2022-05-09T14:00:31Z

On Mon, 9 May 2022 14:08:05 +0200
Nico Boehr <nrb@linux.ibm.com> wrote:

> When a VM is migrated, we expect the page states to be preserved. Add a test
> which checks for that.
>
> Signed-off-by: Nico Boehr <nrb@linux.ibm.com>
> ---
> s390x/Makefile | 1 +
> s390x/cmm-migration.c | 78 +++++++++++++++++++++++++++++++++++++++++++
> s390x/unittests.cfg | 4 +++
> 3 files changed, 83 insertions(+)
> create mode 100644 s390x/cmm-migration.c
>
> diff --git a/s390x/Makefile b/s390x/Makefile
> index a8e04aa6fe4d..8ac0afdfd994 100644
> --- a/s390x/Makefile
> +++ b/s390x/Makefile
> @@ -32,6 +32,7 @@ tests += $(TEST_DIR)/epsw.elf
> tests += $(TEST_DIR)/adtl-status.elf
> tests += $(TEST_DIR)/migration.elf
> tests += $(TEST_DIR)/pv-attest.elf
> +tests += $(TEST_DIR)/cmm-migration.elf
>
> pv-tests += $(TEST_DIR)/pv-diags.elf
>
> diff --git a/s390x/cmm-migration.c b/s390x/cmm-migration.c
> new file mode 100644
> index 000000000000..4a7b50e40fc6
> --- /dev/null
> +++ b/s390x/cmm-migration.c
> @@ -0,0 +1,78 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * CMM migration tests (ESSA)
> + *
> + * Copyright IBM Corp. 2022
> + *
> + * Authors:
> + * Nico Boehr <nrb@linux.ibm.com>
> + */
> +
> +#include <libcflat.h>
> +#include <asm/asm-offsets.h>
> +#include <asm/interrupt.h>
> +#include <asm/page.h>
> +#include <asm/cmm.h>
> +#include <bitops.h>
> +
> +#define NUM_PAGES 128
> +static uint8_t pagebuf[NUM_PAGES][PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
> +
> +static void test_migration(void)
> +{
> + int i, state_mask, actual_state;
> + /*
> + * Maps ESSA actions to states the page is allowed to be in after the
> + * respective action was executed.
> + */
> + int allowed_essa_state_masks[4] = {
> + BIT(ESSA_USAGE_STABLE), /* ESSA_SET_STABLE */
> + BIT(ESSA_USAGE_UNUSED), /* ESSA_SET_UNUSED */
> + BIT(ESSA_USAGE_VOLATILE), /* ESSA_SET_VOLATILE */
> + BIT(ESSA_USAGE_VOLATILE) | BIT(ESSA_USAGE_POT_VOLATILE) /* ESSA_SET_POT_VOLATILE */
> + };
> +
> + for (i = 0; i < NUM_PAGES; i++) {
> + switch(i % 4) {
> + case 0:
> + essa(ESSA_SET_STABLE, (unsigned long)pagebuf[i]);
> + break;
> + case 1:
> + essa(ESSA_SET_UNUSED, (unsigned long)pagebuf[i]);
> + break;
> + case 2:
> + essa(ESSA_SET_VOLATILE, (unsigned long)pagebuf[i]);
> + break;
> + case 3:
> + essa(ESSA_SET_POT_VOLATILE, (unsigned long)pagebuf[i]);
> + break;

const int essa_commands[4] = {ESSA_SET_STABLE, ESSA_SET_UNUSED, ...

for (i = 0; i < NUM_PAGES; i++)
essa(essa_commands[i % 4], ...

I think it would look more compact and more readable

> + }
> + }
> +
> + puts("Please migrate me, then press return\n");
> + (void)getchar();
> +
> + for (i = 0; i < NUM_PAGES; i++) {
> + actual_state = essa(ESSA_GET_STATE, (unsigned long)pagebuf[i]);
> + /* extract the usage state in bits 60 and 61 */
> + actual_state = (actual_state >> 2) & 0x3;
> + state_mask = allowed_essa_state_masks[i % ARRAY_SIZE(allowed_essa_state_masks)];
> + report(BIT(actual_state) & state_mask, "page %d state: expected_mask=0x%x actual_mask=0x%lx", i, state_mask, BIT(actual_state));
> + }
> +}
> +
> +int main(void)
> +{
> + bool has_essa = check_essa_available();
> +
> + report_prefix_push("cmm-migration");
> + if (!has_essa) {
> + report_skip("ESSA is not available");
> + goto done;
> + }
> +
> + test_migration();
> +done:
> + report_prefix_pop();
> + return report_summary();
> +}
> diff --git a/s390x/unittests.cfg b/s390x/unittests.cfg
> index b456b2881448..625026d90e52 100644
> --- a/s390x/unittests.cfg
> +++ b/s390x/unittests.cfg
> @@ -176,3 +176,7 @@ extra_params = -cpu qemu,gs=off,vx=off
> file = migration.elf
> groups = migration
> smp = 2
> +
> +[cmm-migration]
> +file = cmm-migration.elf
> +groups = migration